Vitamin D - Knowledge

952:, alfacalcidol, and calcitriol) do not appear to have any beneficial effects with regard to the risk of death. High blood levels appear to be associated with a lower risk of death, but it is unclear if supplementation can result in this benefit. Both an excess and a deficiency in vitamin D appear to cause abnormal functioning and premature aging. The relationship between serum calcifediol concentrations and all-cause mortality is "U-shaped": mortality is elevated at high and low calcifediol levels, relative to moderate levels. Harm from vitamin D appears to occur at a lower vitamin D level in the dark skinned Canadian and United States populations which have been studied than in the light skinned Canadian and United States populations which have been studied. Whether this is so with dark skinned populations in other parts of the world is unknown. 12276:

the oils secreted by skin into fur. Although much of the vitamin D produced within human skin is absorbed directly, birds and furbearing animals acquire most of their vitamin D orally, as they groom themselves (Bicknell and Prescott, 1946; Carpenter and Zhao, 1999). Vitamin D is generated from the oily secretions of skin into fur. The oral consumption of UV-exposed dermal excretion is the way many animals acquire the "nutrient," vitamin D. Although Fraser (1983) has argued that dermal absorption of vitamin D may be more natural, what we know from animals indicates that oral consumption is equally physiological. Since vitamin D can be extracted from UV-exposed human sweat and skin secretions (Bicknell and Prescott, 1946), it is also reasonable to think that early humans obtained some of their vitamin D by mouth as well, by licking the skin.

3957:: 0.36) compared to those without supplementation, but without a change in mortality. A Cochrane review, also of three studies, found the evidence for the effectiveness of vitamin D supplementation for the treatment of COVID-19 to be very uncertain. They found there was substantial clinical and methodological heterogeneity in the three studies that were included, mainly because of different supplementation strategies, vitamin D formulations (one using calcifediol), pre-treatment status and reported outcomes. Another meta-analysis stated that the use of high doses of vitamin D in people with COVID-19 is not based on solid evidence although calcifediol supplementation may have a protective effect on ICU admissions. 3946:

significantly increased the susceptibility to becoming infected with COVID-19 and having severe COVID-19, with odds ratios of 1.5 and 1.9 respectively, but these findings had high risk of bias and heterogeneity. A two-fold greater mortality was found, but this analysis was less robust. These findings confirm smaller, earlier analyses, one of which, in reporting that people with COVID-19 tend to have lower 25(OH)D levels than healthy subjects, stated that the trend for associations with health outcomes was limited by the low quality of the studies and by the possibility of reverse causality mechanisms.

357:. Vitamin D supplements are commonly used to treat or to prevent osteomalacia and rickets. The evidence for other health benefits of vitamin D supplementation in individuals who are already vitamin D sufficient is inconsistent. The effect of vitamin D supplementation on morbidity and mortality is also unclear, with one meta-analysis finding a small decrease in mortality in elderly people. Except for the prevention of rickets and osteomalacia in high-risk groups, any benefit of vitamin D supplements to musculoskeletal or general health may be small and in some cases, may have adverse effects on health. 3149: 2508: 964:. Its general use for prevention of this disease in those without vitamin D deficiency is thus likely not needed. For older people with osteoporosis, taking vitamin D with calcium may help prevent hip fractures, but it also slightly increases the risk of stomach and kidney problems. A study found that supplementation with 800 IU or more daily, in those older than 65 years was "somewhat favorable in the prevention of hip fracture and non-vertebral fracture". The effect is small or none for people living independently. Low serum vitamin D levels have been associated with 1287:, and small (for gestational age) infants. Although taking vitamin D supplements during pregnancy raises blood levels of vitamin D in the mother at term, the full extent of benefits for the mother or baby is unclear. Pregnant women who take an adequate amount of vitamin D during gestation may experience a lower risk of pre-eclampsia and positive immune effects. Vitamin D supplementation is also likely to reduce the risk of gestational diabetes, undersized babies and of their poor rate of growth. Pregnant women often do not take the recommended amount of vitamin D. 834:, almost two-thirds of 500 children had mild rickets in the late 1920s. An increase in the proportion of animal protein in the 20th century American diet coupled with increased consumption of milk fortified with relatively small quantities of vitamin D coincided with a dramatic decline in the number of rickets cases. Also, in the United States and Canada, vitamin D-fortified milk, infant vitamin supplements, and vitamin supplements have helped to eradicate the majority of cases of rickets for children with fat malabsorption conditions. 3473: 3488: 5749: 3157: 465: 418: 492: 587: 70: 445: 3942:(NICE) does not recommend to offer a vitamin D supplement to people solely to prevent or treat COVID-19. Both organizations included recommendations to continue the previous established recommendations on vitamin D supplementation for other reasons, such as bone and muscle health, as applicable. Both organizations noted that more people may require supplementation due to lower amounts of sun exposure during the pandemic. 14299: 1089:

melanoma. Several drug classes and natural health products can modulate vitamin D-related CYP enzymes, potentially causing lower levels of vitamin D and its active metabolites in tissues, suggesting that maintaining adequate vitamin D levels, that is, avoiding vitamin D deficiency, either through dietary supplements or by modulating CYP metabolism, could be beneficial in decreasing the risk of melanoma development.

1202:. Another meta-analysis reported that vitamin D supplementation significantly improved glycemic control , hemoglobin A1C (HbA1C), and fasting blood glucose (FBG) in individuals with type 2 diabetes. In prospective studies, high versus low level of vitamin D was respectively associated with significant decrease in risk of type 2 diabetes, combined type 2 diabetes and prediabetes, and prediabetes. A 2011 16040: 13727: 11523: 10539: 10503: 10467: 10431: 10293: 10077: 9844: 9770: 9672: 9355: 7489: 3916:

stroke, cerebrovascular disease, cancer) by more than 15%, and that further research trials with similar design are unlikely to change these conclusions. As of 2022, there is insufficient evidence for an effect of vitamin D supplementation on the risk of cancer. A 2019 meta-analysis found a small increase in risk of stroke when calcium and vitamin D supplements were taken together.

268:. Foods such as the flesh of fatty fish are good sources of vitamin D, though there are few other foods where it naturally appears in significant amounts. In the U.S. and other countries, cow's milk and plant-based milk substitutes are fortified with vitamin D, as are many breakfast cereals. Mushrooms exposed to ultraviolet light also provide useful amounts of vitamin D 322:(also known as calcidiol or 25-hydroxycholecalciferol), while ergocalciferol is converted to ercalcidiol (25-hydroxyergocalciferol). These two vitamin D metabolites, collectively referred to as 25-hydroxyvitamin D or 25(OH)D, are measured in serum to assess a person's vitamin D status. Calcifediol is further hydroxylated by the kidneys and certain immune cells to form 3312: 761:

between 12–20 ng/mL (30–50 nmol/liter). It is estimated that one billion adults worldwide are either vitamin D insufficient or deficient, including those in developed countries across Europe. Severe vitamin D deficiency in children, although rare in the developed world, can cause a softening and weakening of growing bones, leading to a condition known as

1895:(UL) is defined as "the highest average daily intake of a nutrient that is likely to pose no risk of adverse health effects for nearly all persons in the general population." Although ULs are believed to be safe, information on the long-term effects is incomplete and these levels of intake are not recommended for long-term consumption. 1953:(EFSA) in 2016 reviewed the current evidence, finding the relationship between serum 25(OH)D concentration and musculoskeletal health outcomes is widely variable. They considered that average requirements and population reference intakes values for vitamin D cannot be derived, and that a serum 25(OH)D concentration of 50 3567:, and also by low calcium or phosphate. Following the final converting step in the kidney, calcitriol is released into the circulation. By binding to vitamin D-binding protein, calcitriol is transported throughout the body, including to the intestine, kidneys, and bones. Calcitriol is the most potent natural 3773:

from vitamin A. He called it vitamin D because he thought it was the fourth vitamin to be named. It was not initially realized that vitamin D can be synthesized by humans (in the skin) through exposure to UV light, and therefore is technically not a vitamin, but rather can be considered to be a hormone.

891:. On the other hand, the effects of vitamin D supplementation on non-skeletal health are uncertain. A review did not find any effect from supplementation on the rates of non-skeletal disease, other than a tentative decrease in mortality in the elderly. Vitamin D supplements do not alter the outcomes for 12275:

The high 25(OH)D concentrations, and relatively high vitamin D requirements of apes and monkeys are understandable in light of their biology—their body surface area relative to mass is generally greater than for humans, and they are inveterate groomers, consuming by mouth the vitamin D generated from

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and concluded vitamin A, or a closely associated factor, could prevent the disease. In 1922, Elmer McCollum tested modified cod liver oil in which the vitamin A had been destroyed. The modified oil cured the sick dogs, so McCollum concluded the factor in cod liver oil which cured rickets was distinct

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nmol/L) were to be recommended for athletes. Part of the controversy is because numerous studies have found differences in serum levels of 25(OH)D between ethnic groups; studies point to genetic as well as environmental reasons behind these variations. Supplementation to achieve these standard levels

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in 2015), superseded previous recommendations which were expressed in terms of adequate intake. The recommendations were formed assuming the individual has no skin synthesis of vitamin D because of inadequate sun exposure. The reference intake for vitamin D refers to total intake from food, beverages

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There is some evidence that vitamin D supplementation therapy for people with inflammatory bowel disease may be associated with improvements in scores for clinical inflammatory bowel disease activity and biochemical markers. Vitamin D treatment may be associated with less frequent relapse of symptoms

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found a decrease in mortality in elderly people. Another meta-analysis covering over 350,000 people concluded that vitamin D supplementation in unselected community-dwelling individuals does not reduce skeletal (total fracture) or non-skeletal outcomes (myocardial infarction, ischemic heart disease,

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could not be linked reliably with intake of either calcium or vitamin D, and were often conflicting." Some researchers claim the IOM was too definitive in its recommendations and made a mathematical mistake when calculating the blood level of vitamin D associated with bone health. Members of the IOM

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Although rickets and osteomalacia are now rare in the United Kingdom, outbreaks have happened in some immigrant communities in which people with osteomalacia included women with seemingly adequate daylight outdoor exposure wearing Western clothing. Having darker skin and reduced exposure to sunshine

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in the skin, which hinders vitamin D synthesis, makes dark-skinned individuals less efficient at producing vitamin D. In the U.S., vitamin D deficiency is particularly common among Hispanic and African-American populations, with levels dropping significantly in the winter due to melanin’s protective

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ml/day, and children aged 6 months to 4 years, should take daily vitamin D supplements throughout the year to ensure sufficient intake. This includes people with limited skin synthesis of vitamin D, who are not often outdoors, are frail, housebound, living in a care home, or usually wearing clothes

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to discuss possible structures, which contributed to bringing a team together. X-ray crystallography demonstrated the sterol molecules were flat, not as proposed by the German team led by Windaus. In 1932, Otto Rosenheim and Harold King published a paper putting forward structures for sterols and

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Vitamin D toxicity is treated by discontinuing vitamin D supplementation and restricting calcium intake. Kidney damage may be irreversible. Exposure to sunlight for extended periods of time does not normally cause vitamin D toxicity. The concentrations of vitamin D precursors produced in the skin

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nmol/L) is needed for bone and overall health. The dietary reference intakes for vitamin D are chosen with a margin of safety and 'overshoot' the targeted serum value to ensure the specified levels of intake achieve the desired serum 25(OH)D levels in almost all persons. No contributions to serum

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are responsible for the degradation of the active vitamin D. CYP24A1, the primary catabolic enzyme of calcitriol, is overexpressed in melanoma tissues and cells. This overexpression could lead to lower levels of active vitamin D in tissues, potentially promoting the development and progression of

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Vitamin D deficiency remains the main cause of rickets among young infants in most countries because breast milk is low in vitamin D and social customs and climatic conditions can prevent adequate sun exposure. In sunny countries such as Nigeria, South Africa, and Bangladesh, where rickets occurs

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characterized by bow legs, which can be caused by calcium or phosphorus deficiency, as well as a lack of vitamin D; in the 21st century, it is largely found in low-income countries in Africa, Asia, or the Middle East and in those with genetic disorders such as pseudo-vitamin-D-deficiency rickets.

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that bend and bow under their weight as children start to walk. Rickets typically appear between 3 and 18 months of age. Cases continue to be reported in North American and other Western Countries and is primarily seen in breastfed infants and those with darker skin complexions. This condition is

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The authors conclude that there is therefore little reason to use vitamin D supplements to maintain or improve musculoskeletal health, except for the prevention of rare conditions such as rickets and osteomalacia in high risk groups, which can be caused by vitamin D deficiency after long lack of

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European Food Safety Authority (EFSA) Panel on Dietetic Products, Nutrition and Allergies (NDA) (2010). "Scientific opinion on the substantiation of health claims related to vitamin D and normal function of the immune system and inflammatory response (ID 154, 159), maintenance of normal muscle

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Several systematic reviews and meta-analyses of multiple studies have described the associations of vitamin D deficiency with adverse outcomes in COVID-19. In the largest analysis, with data from 76 observational studies including almost two million adults, vitamin D deficiency or insufficiency

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and the weaker the sunlight, the more minutes of exposure are needed. It also depends on parts of body exposed, all three factors affect minimal erythema dose (MED). Vitamin D overdose from UV exposure is impossible: the skin reaches an equilibrium where the vitamin D degrades as fast as it is

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A diet insufficient in vitamin D, combined with inadequate sunlight exposure, can lead to vitamin D deficiency, which is defined as a blood 25-hydroxyvitamin D or 25(OH)D level below 12 ng/mL (30 nmol/liter). Vitamin D insufficiency, on the other hand, is characterized by a blood 25(OH)D level

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Vitamin D overdose causes hypercalcemia, which is a strong indication of vitamin D toxicity – this can be noted with an increase in urination and thirst. If hypercalcemia is not treated, it results in excess deposits of calcium in soft tissues and organs such as the kidneys, liver, and heart,

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have lower vitamin D levels, and that there was a small association between low vitamin D levels at the time of birth and later development of ADHD. Several small, randomized controlled trials of vitamin D supplementation indicated improved ADHD symptoms such as impulsivity and hyperactivity.

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muscle weakness, bone fragility, and increased risk for fractures. Osteomalacia reduces calcium absorption and increases calcium loss from bone, which increases the risk for bone fractures. Osteomalacia is usually present when 25-hydroxyvitamin D levels are less than about

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spectrum, but typically produce 4% to 10% of the total UV emissions as UVB, some tanning beds can use only separate UVB light bulbs specifically for vitamin D production). Exposure to light through windows is insufficient because glass almost completely blocks UVB light.

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Hernández-Alonso P, Boughanem H, Canudas S, Becerra-Tomás N, Fernández de la Puente M, Babio N, et al. (July 2021). "Circulating vitamin D levels and colorectal cancer risk: A meta-analysis and systematic review of case-control and prospective cohort studies".

1259:. However, lower vitamin D concentrations are also associated with poor nutrition and spending less time outdoors. Therefore, alternative explanations for the increase in cognitive impairment exist and hence a direct causal relationship between vitamin D levels and 9455: 3414:

Land vertebrates required another source of vitamin D other than plants for their calcified skeletons. They had to either ingest it or be exposed to sunlight to photosynthesize it in their skin. Land vertebrates have been photosynthesizing vitamin D for more than

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In birds and fur-bearing mammals, fur or feathers block UV rays from reaching the skin. Instead, vitamin D is created from oily secretions of the skin deposited onto the feathers or fur, and is obtained orally during grooming. However, some animals, such as the

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Adequate amounts of vitamin D can be produced with moderate sun exposure to the face, arms and legs (for those with the least melanin), averaging 5–30 minutes twice per week, or approximately 25% of the time for minimal sunburn. The darker the skin on the

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Those who are pregnant or breastfeeding should consult a doctor before taking a vitamin D supplement. The FDA advised manufacturers of liquid vitamin D supplements that droppers accompanying these products should be clearly and accurately marked for 400

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Maternal vitamin D deficiency may cause overt bone disease from before birth and impairment of bone quality after birth. Nutritional rickets exists in countries with intense year-round sunlight such as Nigeria and can occur without vitamin D deficiency.

1145:. The benefits were found in young children and adolescents (ages 1 up to 16 years) and were not confirmed with higher doses (>1000 IU per day or more). Vitamin D supplementation substantially reduces the rate of moderate or severe exacerbations of 1238:

Clinical trials of vitamin D supplementation for depressive symptoms have generally been of low quality and show no overall effect, although subgroup analysis showed supplementation for participants with clinically significant depressive symptoms or

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only. Primitive marine vertebrates are thought to absorb calcium from the ocean into their skeletons and eat plankton rich in vitamin D, although the function in those without a calcified cartilage is unclear. Phytoplankton in the ocean (such as

3693:. This hydroxylation also leads to a greater degree of inactivation: the activity of calcitriol decreases to 60% of original after 24-hydroxylation, whereas ercalcitriol undergoes a 10-fold decrease in activity on conversion to ercalcitetrol. 13803: 1866:

that cover up most of the skin, or with dark skin, such as having an African, African-Caribbean or south Asian background. Other people may be able to make adequate vitamin D from sunlight exposure from April to September. The NHS and

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Sahebi R, Rezayi M, Emadzadeh M, Salehi M, Tayefi M, Parizadeh SM, et al. (February 2019). "The effects of vitamin D supplementation on indices of glycemic control in Iranian diabetics: A systematic review and meta-analysis".

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Chung M, Lee J, Terasawa T, Lau J, Trikalinos TA (December 2011). "Vitamin D with or without calcium supplementation for prevention of cancer and fractures: an updated meta-analysis for the U.S. Preventive Services Task Force".

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in response to any increase in vitamin D nutrition, while maternal hypercalcemia during pregnancy may increase fetal sensitivity to effects of vitamin D and lead to a syndrome of intellectual disability and facial deformities.

2855:(especially in the kidneys) may develop. Other symptoms of vitamin D toxicity include intellectual disability in young children, abnormal bone growth and formation, diarrhea, irritability, weight loss, and severe depression. 1181:

in IBD. It is not clear if this treatment improves the person's quality of life or what the clinical response to vitamin D treatment. The ideal treatment regime and dose of vitamin D therapy has not been well enough studied.

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supplementation has been tentatively found to lead to a reduced risk of death in the elderly, but the effect has not been deemed pronounced, or certain enough, to make taking supplements recommendable. Other forms (vitamin

9439: 1177:. Deficiencies in vitamin D have been linked to the severity of the case of inflammatory bowel disease, however, whether vitamin D deficiency causes inflammatory bowel disease or is a symptom of the disease is not clear. 9896: 3845:

of his own money, Steenbock patented his invention. His irradiation technique was used for foodstuffs, most notably for milk. By the expiration of his patent in 1945, rickets had been all but eliminated in the US.

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demonstrated that irradiation by ultraviolet light increased the vitamin D content of foods and other organic materials. After irradiating rodent food, Steenbock discovered the rodents were cured of rickets. Using

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Gan J, Galer P, Ma D, Chen C, Xiong T (November 2019). "The Effect of Vitamin D Supplementation on Attention-Deficit/Hyperactivity Disorder: A Systematic Review and Meta-Analysis of Randomized Controlled Trials".

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Low levels of 25-hydroxyvitamin D, a routinely used marker for vitamin D, have been suggested as a contributing factor in increasing the risk the development and progression of various types of cancer, including

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did not produce rickets unless the diet deviated from a Western omnivore pattern characterized by high intakes of meat, fish, and eggs. The dietary risk factors for rickets include abstaining from animal foods.

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Mohammadi S, Hajhashemy Z, Saneei P (June 2021). "Serum vitamin D levels in relation to type-2 diabetes and prediabetes in adults: a systematic review and dose-response meta-analysis of epidemiologic studies".

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Vitamin D toxicity is rare. It is caused by supplementing with high doses of vitamin D rather than sunlight. The threshold for vitamin D toxicity has not been established; however, according to some research:

1355:"Adequate calcium and regular exercise may help to achieve strong bones in children and adolescents and may reduce the risk of osteoporosis in older adults. An adequate intake of vitamin D is also necessary." 12423:

is produced commercially by extracting 7-dehydrocholesterol from wool fat, followed by UVB irradiation and purification is commercially made by irradiating and then purifying the ergosterol extracted from

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Calcifediol is transported to the proximal tubules of the kidneys, where it is hydroxylated at the 1-α position (lower right of the molecule) to form calcitriol (1,25-dihydroxycholecalciferol, 1,25(OH)

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Recommendations on recommended 25(OH)D serum levels vary across authorities, and vary based on factors like age. US labs generally report 25(OH)D levels in ng/mL. Other countries often use nmol/L. One

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Wahl DA, Cooper C, Ebeling PR, Eggersdorfer M, Hilger J, Hoffmann K, et al. (1 February 2013). "A global representation of vitamin D status in healthy populations: reply to comment by Saadi".

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Zhao Y, Chen C, Pan W, Gao M, He W, Mao R, et al. (May 2016). "Comparative efficacy of vitamin D status in reducing the risk of bladder cancer: A systematic review and network meta-analysis".

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with increased bone fragility and risk of bone fractures. Osteoporosis can be a long-term effect of calcium and/or vitamin D insufficiency, the latter contributing by reducing calcium absorption.

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There is conflicting evidence about the benefits of interventions with vitamin D. Supplementation of between 800 and 1,000 IU is safe, but higher levels leading to blood levels of more than 50

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For US food and dietary supplement labeling purposes, the amount in a serving is expressed as a percent of Daily Value (%DV). For vitamin D labeling purposes, 100% of the daily value was 400

871:, there is no persuasive evidence of lower vitamin D levels in people with chronic pain or that supplementation alleviates chronic nonspecific musculoskeletal pain. Osteomalacia progress to 9340: 8184: 272:. Dietary recommendations typically assume that all of a person's vitamin D is taken by mouth, given the variability in sunlight exposure among the population and uncertainties regarding 9164:

Pathak K, Soares MJ, Calton EK, Zhao Y, Hallett J (June 2014). "Vitamin D supplementation and body weight status: a systematic review and meta-analysis of randomized controlled trials".

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Holick MF, MacLaughlin JA, Clark MB, Holick SA, Potts JT, Anderson RR, et al. (October 1980). "Photosynthesis of previtamin D3 in human skin and the physiologic consequences".

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Hussain S, Singh A, Akhtar M, Najmi AK (September 2017). "Vitamin D supplementation for the management of knee osteoarthritis: a systematic review of randomized controlled trials".

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gene, leading to a reduction in the degradation of vitamin D. Infants who have such a mutation have an increased sensitivity to vitamin D and in case of additional intake a risk of

12290:"Cholecalciferol supplementation alters gut function and improves digestibility in an underground inhabitant, the naked mole rat (Heterocephalus glaber), when fed on a carrot diet" 3427:, are naturally cholecalciferol-deficient, as serum 25-OH vitamin D levels are undetectable. Dogs and cats are practically incapable of vitamin D synthesis due to high activity of 1914:μg) to bring it into agreement with the recommended dietary allowance (RDA). Compliance with the updated labeling regulations was required by 1 January 2020 for manufacturers with 13770: 3853:

was identified. Shortly thereafter, the conversion of vitamin D to calcifediol and then to calcitriol, the biologically active form, was confirmed. The photosynthesis of vitamin D

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was not to patent discoveries, believing the results of medical research should be open to everybody. In the 1930s, Windaus clarified further the chemical structure of vitamin D.

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published recommended dietary intakes (DRIs) and tolerable upper intake levels (ULs) for vitamin D based on the jointly commissioned and funded Institute of Medicine 2010 report.

3723:(VDRE) which are specific DNA sequences on genes. Transcription of these genes is stimulated and produces greater levels of the proteins which mediate the effects of vitamin D. 1941:

Australia and New Zealand published nutrient reference values including guidelines for dietary vitamin D intake in 2006. About a third of Australians have vitamin D deficiency.

1307:. A 2016 meta-analysis found that circulating vitamin D status was improved by weight loss, indicating that fat mass may be inversely associated with blood levels of vitamin D. 776:) levels can result from limited sun exposure. When vitamin D levels are deficient, the total absorption of dietary calcium can decrease from the normal range of 60–80% to 15%. 2784:

A study published in 2017 assessed the prevalence of high daily intake levels of supplemental vitamin D among adults ages 20+ in the United States, based on publicly available

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and/or major breaks, particularly those engaging in contact sports. The greatest benefit with supplementation is seen in athletes who are deficient (25(OH)D serum levels <30

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among older toddlers and children, it has been attributed to low dietary calcium intakes, which are characteristic of cereal-based diets with limited access to dairy products.

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of vitamin D. These vary according to precise definition, age, pregnancy or lactation, and the extent assumptions are made regarding skin synthesis of vitamin D. Conversion: 1

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Bolland MJ, Grey A, Gamble GD, Reid IR (April 2014). "The effect of vitamin D supplementation on skeletal, vascular, or cancer outcomes: a trial sequential meta-analysis".

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Synthesis of vitamin D in nature is dependent on the presence of UV radiation and subsequent activation in the liver and in the kidneys. Many animals synthesize vitamin D

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Damascena AD, Azevedo LM, Oliveira TA, Santana JD, Pereira M (August 2021). "Addendum to vitamin D deficiency aggravates COVID-19: systematic review and meta-analysis".

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In the epidermal strata of the skin, vitamin D production is greatest in the stratum basale (colored red in the illustration) and stratum spinosum (colored light brown).

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The percentage of the population taking over 1000 IU/day, as well as the percentage taking over 4000 IU/day, have both increased since 1999, according to trend analysis.

12856:"Membrane-mediated actions of 1,25-dihydroxy vitamin D3: a review of the roles of phospholipase A2 activating protein and Ca(2+)/calmodulin-dependent protein kinase II" 11909:"Serum concentrations of lipids, vitamin d metabolites, retinol, retinyl esters, tocopherols and selected carotenoids in twelve captive wild felid species at four zoos" 8401:

Guzman-Prado Y, Samson O, Segal JP, Limdi JK, Hayee B (May 2020). "Vitamin D Therapy in Adults With Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis".

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Norman AW, Myrtle JF, Midgett RJ, Nowicki HG, Williams V, Popják G (July 1971). "1,25-dihydroxycholecalciferol: identification of the proposed active form of vitamin D

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have not confirmed that vitamin D supplements reduce the risk of cancer incidence, the relative risk of cancer deaths was lower by up to 16% in several meta-analyses.

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Schöttker B, Jorde R, Peasey A, Thorand B, Jansen EH, Groot L, et al. (Consortium on Health Ageing: Network of Cohorts in Europe the United States) (June 2014).

8817:"Correlation between total vitamin D levels and psychotic psychopathology in patients with schizophrenia: therapeutic implications for add-on vitamin D augmentation" 10761: 10416: 5083:

Puchacz E, Stumpf WE, Stachowiak EK, Stachowiak MK (February 1996). "Vitamin D increases expression of the tyrosine hydroxylase gene in adrenal medullary cells".

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or in soy beverage products. Plant milks are defined as beverages made from soy, almond, rice, among other plant sources intended as alternatives to dairy milk.

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or more in annual food sales, and by 1 January 2021 for manufacturers with lower volume food sales. A table of the old and new adult daily values is provided at

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Institute of Medicine (US) Committee to Review Dietary Reference Intakes for Vitamin D and Calcium (2011). Ross AC, Taylor CL, Yaktine AL, Del Valle HB (eds.).

8869:"Association between maternal serum 25-hydroxyvitamin D level and pregnancy and neonatal outcomes: systematic review and meta-analysis of observational studies" 326:(1,25-dihydroxycholecalciferol), the biologically active form of vitamin D. Calcitriol circulates in the blood as a hormone, playing a major role in regulating 13536:

Pyrżak B, Witkowska-Sędek E, Krajewska M, Demkow U, Kucharska AM (2015). "Metabolic and immunological consequences of vitamin D deficiency in obese children".

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Wallace C, Gordon M, Sinopoulou V, Limketkai BN, et al. (Cochrane Gut Group) (October 2023). "Vitamin D for the treatment of inflammatory bowel disease".

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IU). One thousand micrograms per day in infants has produced toxicity within one month. After being commissioned by the Canadian and American governments, the

11512: 10275: 7897:"Effect of Vitamin D on Blood Pressure and Hypertension in the General Population: An Update Meta-Analysis of Cohort Studies and Randomized Controlled Trials" 3575:, which mediates most of the physiological actions of vitamin D. In addition to the kidneys, calcitriol is also synthesized by certain other cells, including 2710:

Published cases of toxicity involving hypercalcemia in which the vitamin D dose and the 25-hydroxy-vitamin D levels are known all involve an intake of ≥40,000

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and causes bone damage, leading to bone-softening diseases such as rickets in children and osteomalacia in adults. Low blood calcifediol (25-hydroxyvitamin D

124: 9283:"Scientific opinion on the substantiation of a health claim related to vitamin D and risk of falling pursuant to Article 14 of Regulation (EC) No 1924/2006" 855:

is a disease in adults that results from vitamin D deficiency. Characteristics of this disease are softening of the bones, leading to bending of the spine,

10947: 7242:"Association Between Calcium or Vitamin D Supplementation and Fracture Incidence in Community-Dwelling Older Adults: A Systematic Review and Meta-analysis" 3804:

in Hampstead, London, were working on the structure of vitamin D, which was still unknown, as well as the structure of steroids. A meeting took place with

3384:, possibly helping to prevent DNA damage by absorbing UVB, making vitamin D an inactive end product. The familiar vitamin D endocrine machinery containing 11356: 1217:

alone. However, it is important to highlight that the studies available to be included in this review presented considerable flaws in quality and design.

295:. Since most mammals can synthesise sufficient vitamin D with adequate sunlight exposure, it is technically not essential in the diet and thus not a true 1315:

Governmental regulatory agencies stipulate for the food and dietary supplement industries certain health claims as allowable as statements on packaging.

342:. Additionally, calcitriol has other effects, including influencing cell differentiation, neuromuscular and immune functions, and reducing inflammation. 12267: 1020:, as "nutrients of public health significance", since May 2016. By a proposed deadline extension, some manufacturers had until 1 July 2021, to comply. 9693: 9117:"Association Between Vitamin D Supplementation During Pregnancy and Offspring Growth, Morbidity, and Mortality: A Systematic Review and Meta-analysis" 3447:

to UVB and UVC light, followed by purification. The 7-dehydrocholesterol is a natural substance in fish organs, especially the liver, in wool grease (

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nmol/L was a suitable target value. For all people over the age of 1, including women who are pregnant or lactating, they set an adequate intake of 15

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One of the most important functions of vitamin D is to maintain skeletal calcium balance by promoting calcium absorption in the intestines, promoting

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Vitamin D deficiency is prevalent globally, particularly among the elderly, and remains common in both children and adults. This deficiency impairs

6892:"Vitamin D and mortality: meta-analysis of individual participant data from a large consortium of cohort studies from Europe and the United States" 13589: 9494: 9307: 8208:"Vitamin D to prevent exacerbations of COPD: systematic review and meta-analysis of individual participant data from randomised controlled trials" 3368:

of two innermost strata of the epidermis, the stratum basale and stratum spinosum, which also are able to produce calcitriol and express the VDR.

3070: 2926: 10564: 9332: 3726:

Some reactions of the cell to calcitriol appear to be too fast for the classical VDRE transcription pathway, leading to the discovery of various

8176: 6612:"Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of observational studies and randomised trials" 4702:"The Lancet Diabetes & Endocrinology: Vitamin D supplementation in adults does not prevent fractures, falls or improve bone mineral density" 3892:

over 2004–18 to track current research and provide education to consumers. As of 2022, the role of vitamin D in the prevention and treatment of

3719:

Calcitriol enters the target cell and binds to the vitamin D receptor in the cytoplasm. This activated receptor enters the nucleus and binds to

15951: 4612:

Reid IR, Bolland MJ, Grey A (January 2014). "Effects of vitamin D supplements on bone mineral density: a systematic review and meta-analysis".

539:

of 7-dehydrocholesterol. Although a chemical nomenclature for vitamin D forms was recommended in 1981, alternative names remain commonly used.

7750:"Vitamin D Supplementation and Cardiovascular Disease Risks in More Than 83 000 Individuals in 21 Randomized Clinical Trials: A Meta-analysis" 15946: 12467: 10036: 9752: 4119: 9918: 9866: 9531: 8438:"Effects of Vitamin D Supplementation on Prevention of Type 2 Diabetes in Patients With Prediabetes: A Systematic Review and Meta-analysis" 3520:

at position 25 (upper right of the molecule) to form 25-hydroxycholecalciferol (calcifediol or 25(OH)D). This reaction is catalyzed by the

1271:

Trials have demonstrated lower vitamin D levels are highly prevalent in people with schizophrenia, particularly those with acute episodes.

11948:

Holick MF (2018). "Chapter 4: Photobiology of Vitamin D". In Feldman D, Pike JW, Bouillon R, Giovannucci E, Goltzman D, Hewison M (eds.).

5219: 3323:

is produced photochemically from 7-dehydrocholesterol in the skin of most vertebrate animals, including humans. The precursor of vitamin D

3068: 2924: 15835: 15339: 15311: 15208: 9254:

function (ID 155) and maintenance of normal cardiovascular function (ID 159) pursuant to Article 13(1) of Regulation (EC) No 1924/2006".

5048:

Watkins RR, Lemonovich TL, Salata RA (May 2015). "An update on the association of vitamin D deficiency with common infectious diseases".

1028:

Potential associations have been found between low vitamin D levels and the risk of developing several types of cancer. Meta-analyses of

13933:"Therapeutic and prognostic role of vitamin D for COVID-19 infection: A systematic review and meta-analysis of 43 observational studies" 13747: 10674:"Serum concentrations of 1,25-dihydroxyvitamin D2 and 1,25-dihydroxyvitamin D3 in response to vitamin D2 and vitamin D3 supplementation" 5535:"The uncertain significance of low vitamin D levels in African descent populations: a review of the bone and cardiometabolic literature" 4737:"Effectiveness of vitamin D2 compared with vitamin D3 replacement therapy in a primary healthcare setting: a retrospective cohort study" 2734:

ng cholecalciferol/ergocalciferol). In addition, for products intended for infants, the FDA recommends the dropper hold no more than 400

2489:

Vitamin D content in typical foods is reduced variably by cooking. Boiled, fried and baked foods retained 69–89% of original vitamin D.

15999: 15994: 10977: 10002: 9209:"Vitamin D status and weight loss: a systematic review and meta-analysis of randomized and nonrandomized controlled weight-loss trials" 13241:

Ivory tower and industrial innovation: university-industry technology transfer before and after the Bayh-Dole Act in the United States

11651:. The National Academies Collection: Reports funded by National Institutes of Health. Washington (DC): National Academies Press (US). 4060: 3938:

state there is insufficient evidence to recommend for or against using vitamin D supplementation to prevent or treat COVID-19. The UK

3082: 2938: 15936: 11253: 11197:"The 2011 report on dietary reference intakes for calcium and vitamin D from the Institute of Medicine: what clinicians need to know" 9723: 6865: 3826: 1345:"Adequate calcium and vitamin D, as part of a well balanced diet, along with physical activity, may reduce the risk of osteoporosis." 12084:

Holick MF (February 2002). "Vitamin D: the underappreciated D-lightful hormone that is important for skeletal and cellular health".

11096:"Genetic and environmental determinants of 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D levels in Hispanic and African Americans" 9817: 7848:"Effect of Vitamin D Supplementation on Blood Pressure: A Systematic Review and Meta-analysis Incorporating Individual Patient Data" 4907:

Bouillon R, Van Cromphaut S, Carmeliet G (February 2003). "Intestinal calcium absorption: Molecular vitamin D mediated mechanisms".

12407: 3552: 3079: 3077: 3073: 2935: 2933: 2929: 2364:, a lichen, increases with exposure to ultraviolet light, and is stimulated by industrial ultraviolet lamps for fortification. The 935:

panel maintain that they used a "standard procedure for dietary recommendations" and that the report is solidly based on the data.

11644: 9657: 7410:

Chibuzor MT, Graham-Kalio D, Osaji JO, Meremikwu MM, et al. (Cochrane Metabolic and Endocrine Disorders Group) (April 2020).

3080: 2936: 672:

levels necessary for bone formation, and facilitating the proper function of parathyroid hormone to sustain serum calcium levels.

15167: 3925: 3801: 2365: 9280: 9252: 2738:

IU. For infants (birth to 12 months), the tolerable upper limit (maximum amount that can be tolerated without harm) is set at 25

15828: 13375:

Holick MF, DeLuca HF, Avioli LV (January 1972). "Isolation and identification of 25-hydroxycholecalciferol from human plasma".

8624:"Vitamin D Status and Attention Deficit Hyperactivity Disorder: A Systematic Review and Meta-Analysis of Observational Studies" 7171: 13654:"Effects of Nutritional Supplements and Dietary Interventions on Cardiovascular Outcomes: An Umbrella Review and Evidence Map" 11542:"Regulation of calcitriol biosynthesis and activity: focus on gestational vitamin D deficiency and adverse pregnancy outcomes" 9372: 3062: 2918: 15409: 14968: 13764: 13553: 13288: 13249: 13210: 13049: 12744: 12261: 12222: 11990: 11957: 11696: 11350: 11016: 10134: 10022: 8012: 7326:

Bolland MJ, Grey A, Gamble GD, Reid IR (July 2014). "Vitamin D supplementation and falls: a trial sequential meta-analysis".

6784: 6373: 6334: 5770:

Wagner CL, Greer FR (November 2008). "Prevention of rickets and vitamin D deficiency in infants, children, and adolescents".

5407: 4879: 4852: 4709: 3076: 3071: 2932: 2927: 1870:

recommend that everyone, including those who are pregnant and breastfeeding, consider taking a daily supplement containing 10

13294: 13255: 13216: 13055: 12750: 12228: 11702: 8085:

Nnoaham KE, Clarke A (February 2008). "Low serum vitamin D levels and tuberculosis: a systematic review and meta-analysis".

6379: 6340: 5413: 4885: 3074: 2930: 2498: 15091: 13514: 11308: 221:, along with numerous other biological functions. In humans, the most significant compounds within this group are vitamin D 13585: 9787: 8719:"Vitamin D supplementation for depressive symptoms: a systematic review and meta-analysis of randomized controlled trials" 6806: 6528:"Does vitamin D supplementation alleviate chronic nonspecific musculoskeletal pain? A systematic review and meta-analysis" 2006:

Non-government organisations in Europe have made their own recommendations. The German Society for Nutrition recommends 20

703:. Additionally, vitamin D influences the immune system, with VDRs being expressed in several white blood cells, including 11660: 10722: 10408: 9398: 3064: 2920: 283:

Vitamin D obtained from the diet or synthesised in the skin is biologically inactive. It becomes active by two enzymatic

273: 13004: 12540:

Göring H (November 2018). "Vitamin D in Nature: A Product of Synthesis and/or Degradation of Cell Membrane Components".

1861:(NHS) recommends that people at risk of vitamin D deficiency, breast-fed babies, formula-fed babies taking less than 500 630:, which are hormone-dependent regulators of gene expression. These receptors are expressed in cells across most organs. 15052: 15024: 14342: 13879:"Association of Vitamin D Status with SARS-CoV-2 Infection or COVID-19 Severity: A Systematic Review and Meta-analysis" 6128:"The role of cereals in the aetiology of nutritional rickets: the lesson of the Irish National Nutrition Survey 1943-8" 4338:

Hollis BW (January 1996). "Assessment of vitamin D nutritional and hormonal status: what to measure and how to do it".

3063: 2919: 2703:

A review published in 2015 noted that adverse effects have been reported only at 25(OH)D serum concentrations above 200

2544:

A 2014 review concluded that the most advantageous serum levels for 25(OH)D for all outcomes appeared to be close to 30

787:

Vitamin D deficiency has also been associated with an increased risk of developing various types of cancer, including

11764:

Holick MF (April 1987). "Photosynthesis of vitamin D in the skin: effect of environmental and life-style variables".

9489: 9449: 7701:"Vitamin D supplementation and total cancer incidence and mortality: a meta-analysis of randomized controlled trials" 3105: 3067: 3065: 2923: 2921: 11424:"CYP24A1 and SLC34A1 genetic defects associated with idiopathic infantile hypercalcemia: from genotype to phenotype" 3069: 2925: 2552:

nmol/L). The optimal vitamin D levels are still controversial and another review concluded that ranges from 30 to 40

1134:

with antibacterial, antiviral and anti-inflammatory effects. Low levels of vitamin D appear to be a risk factor for

779:

Dark-skinned individuals living in temperate climates are more likely to have low vitamin D levels. This is because

15512: 14985: 10268: 9746:"Federal Register May 27, 2016 Food Labeling: Revision of the Nutrition and Supplement Facts Labels. FR page 33982" 7412:"Vitamin D, calcium or a combination of vitamin D and calcium for the treatment of nutritional rickets in children" 4957:"Sunlight and vitamin D for bone health and prevention of autoimmune diseases, cancers, and cardiovascular disease" 4059:. Micronutrient Information Center, Linus Pauling Institute, Oregon State University, Corvallis. 11 February 2021. 3081: 3075: 2937: 2931: 13827:"Low vitamin D status is associated with coronavirus disease 2019 outcomes: a systematic review and meta-analysis" 3949:

A meta-analysis of three studies on the effect of oral vitamin D or calcifediol supplementation indicated a lower

3335:

of 290–315 nm. These wavelengths are present in sunlight, as well as in the light emitted by the UV lamps in

15086: 14657: 11884:

Eyley SC, Williams DH (1975). "Photolytic production of vitamin D. The preparative value of a photo-sensitiser".

8962:"Vitamin D supplementation during pregnancy: state of the evidence from a systematic review of randomised trials" 7462: 5290:

Eriksen EF, Glerup H (2002). "Vitamin D deficiency and aging: implications for general health and osteoporosis".

5123:"Evaluation, treatment, and prevention of vitamin D deficiency: an Endocrine Society clinical practice guideline" 3078: 3072: 2934: 2928: 14085:

Dissanayake HA, de Silva NL, Sumanatilleke M, de Silva SD, Gamage KK, Dematapitiya C, et al. (April 2022).

10939: 10003:

Institute of Medicine (US) Standing Committee on the Scientific Evaluation of Dietary Reference Intakes (1997).

9962:

Pérez-López FR, Brincat M, Erel CT, Tremollieres F, Gambacciani M, Lambrinoudaki I, et al. (January 2012).

8306:"Association Between Inflammatory Bowel Disease and Vitamin D Deficiency: A Systematic Review and Meta-analysis" 6771:. The National Academies Collection: Reports funded by National Institutes of Health. National Academies Press. 4799:"IUPAC-IUB Joint Commission on Biochemical Nomenclature (JCBN): Nomenclature of vitamin D. Recommendations 1981" 3825:

was very productive and led to the isolation and characterization of vitamin D. At this time, the policy of the

3066: 2922: 15618: 15241: 15177: 15071: 13103: 12438:"Tissue distribution of 7-dehydrocholesterol, vitamin D3 and 25-hydroxyvitamin D3 in several species of fishes" 11342: 11333: 10058: 7946:"Vitamin D status and blood pressure in children and adolescents: a systematic review of observational studies" 6982:

Tuohimaa P, Keisala T, Minasyan A, Cachat J, Kalueff A (December 2009). "Vitamin D, nervous system and aging".

3459:(ergocalciferol) is produced in a similar way using ergosterol from yeast or mushrooms as a starting material. 3428: 1950: 1318: 11598:"Trends in Use of High-Dose Vitamin D Supplements Exceeding 1000 or 4000 International Units Daily, 1999–2014" 9947: 9375:. Bureau of Nutritional Sciences Food Directorate, Health Products and Food Branch Health Canada. 1 May 2000. 6662:

Autier P, Boniol M, Pizot C, Mullie P (January 2014). "Vitamin D status and ill health: a systematic review".

3970:

Fish do not synthesise vitamin D in a natural setting and rely on dietary sources. As with mammals, vitamin D

15633: 15101: 15076: 13712: 11145:"Circulating 25-hydroxy-vitamin D and risk of cardiovascular disease: a meta-analysis of prospective studies" 4783:

Vitamin D is a fat-soluble vitamin consisting of vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol)

3935: 3885: 3113: 3096: 1032:

have found reduced risk of cancer incidence related to vitamin D intake and 25(OH)D levels, particularly for

987:

ng/mL). Incremental decreases in risks are observed with rising serum 25(OH)D concentrations plateauing at 50

13077: 11907:

Crissey SD, Ange KD, Jacobsen KL, Slifka KA, Bowen PE, Stacewicz-Sapuntzakis M, et al. (January 2003).

4213:

Lehmann U, Gjessing HR, Hirche F, Mueller-Belecke A, Gudbrandsen OA, Ueland PM, et al. (October 2015).

3800:

in 1928 for his work on the constitution of sterols and their connection with vitamins. In 1929, a group at

1141:

Vitamin D supplementation in low doses (400 to 1000 IU/day) may slightly decrease the overall risk of acute

16016: 15690: 15685: 15427: 15142: 14186:

Stroehlein JK, Wallqvist J, Iannizzi C, Mikolajewska A, Metzendorf MI, Benstoem C, et al. (May 2021).

12027:"A revised action spectrum for vitamin D synthesis by suberythemal UV radiation exposure in humans in vivo" 11516: 10412: 9922: 9823: 9689: 9336: 7468: 5162:

Cashman KD, Dowling KG, Škrabáková Z, Gonzalez-Gross M, Valtueña J, De Henauw S, et al. (April 2016).

3929: 2804: 2407: 1980: 1892: 1887: 1338: 1013: 960:

In general, no good evidence supports the commonly held belief that vitamin D supplements can help prevent

12329:

Zafalon RV, Risolia LW, Pedrinelli V, Vendramini TH, Rodrigues RB, Amaral AR, et al. (January 2020).

11094:

Engelman CD, Fingerlin TE, Langefeld CD, Hicks PJ, Rich SS, Wagenknecht LE, et al. (September 2008).

10449:"Federal Register: Food Additives Permitted for Direct Addition to Food for Human Consumption; Vitamin D2" 3817:

bile acids which found immediate acceptance. The informal academic collaboration between the team members

3631:(cholecalciferol) share a similar mechanism of action as outlined above. Metabolites produced by vitamin D 2502: 1874:μg (400 IU) of vitamin D during autumn and winter because of inadequate sunlight for vitamin D synthesis. 15172: 15152: 14666: 14648: 9281:

European Food Safety Authority (EFSA) Panel on Dietetic Products, Nutrition and Allergies (NDA) (2011).

4560:

Bjelakovic G, Gluud LL, Nikolova D, Whitfield K, Wetterslev J, Simonetti RG, et al. (January 2014).

3058: 2914: 2797: 2774: 1142: 1053: 417: 13704: 12331:"Vitamin D metabolism in dogs and cats and its relation to diseases not associated with bone metabolism" 7799:"Vitamin D supplementation, cardiac events and stroke: A systematic review and meta-regression analysis" 4308: 2600:

25(OH)D level are assumed from sun exposure and the recommendations are fully applicable to people with

16030: 15798: 15680: 11973:

Holick MF (2020). "Sunlight, UV Radiation, Vitamin D, and Skin Cancer: How Much Sunlight do We Need?".

4269:"From vitamin D to hormone D: fundamentals of the vitamin D endocrine system essential for good health" 3818: 3720: 2473:

raises 25(OH)D blood levels faster and remains active in the body longer, others contend that vitamin D

1166: 20: 11845:"Vitamin D: importance in the prevention of cancers, type 1 diabetes, heart disease, and osteoporosis" 10556: 9484: 9282: 8766:

Balion C, Griffith LE, Strifler L, Henderson M, Patterson C, Heckman G, et al. (September 2012).

5954:

Paterson CR, Ayoub D (October 2015). "Congenital rickets due to vitamin D deficiency in the mothers".

5121:

Holick MF, Binkley NC, Bischoff-Ferrari HA, Gordon CM, Hanley DA, Heaney RP, et al. (July 2011).

3793: 3233: 15803: 10999:

Bischoff-Ferrari HA (2008). "Optimal Serum 25-Hydroxyvitamin D Levels for Multiple Health Outcomes".

3604: 3541: 1240: 1149:

in people with baseline 25(OH)D levels under 25nmol/L, but not in those with less severe deficiency.

627: 15361: 8099: 5990: 3327:, 7-dehydrocholesterol is produced in relatively large quantities. 7-Dehydrocholesterol reacts with 1968:

The EFSA reviewed safe levels of intake in 2012, setting the tolerable upper limit for adults at 100

349:

and metabolism. Its discovery was due to effort to identify the dietary deficiency in children with

15432: 14479: 12436:

Takeuchi A, Okano T, Sayamoto M, Sawamura S, Kobayashi T, Motosugi M, et al. (February 1986).

11003:(Review). Advances in Experimental Medicine and Biology. Vol. 810. Springer. pp. 500–25. 10821:

Wahl DA, Cooper C, Ebeling PR, Eggersdorfer M, Hilger J, Hoffmann K, et al. (29 August 2012).

7076:"Vitamin D and vitamin D analogues for preventing fractures in post-menopausal women and older men" 3797: 3525: 3381: 2852: 1883: 700: 458: 172: 12437: 10004: 8206:

Jolliffe DA, Greenberg L, Hooper RL, Mathyssen C, Rafiq R, de Jongh RT, et al. (April 2019).

4843:

Fleet JC, Shapses SA (2020). "Vitamin D". In BP Marriott, DF Birt, VA Stallings, AA Yates (eds.).

15661: 14973: 13793:

Evidence reviews for the use of vitamin D supplementation as prevention and treatment of COVID-19

13162:

Proceedings of the Royal Society of London. Series B, Containing Papers of a Biological Character

9745: 6041:

Fischer PR, Rahman A, Cimma JP, Kyaw-Myint TO, Kabir AR, Talukder K, et al. (October 1999).

5911:

Elidrissy AT (September 2016). "The Return of Congenital Rickets, Are We Missing Occult Cases?".

5215: 4115: 3837: 3776:

In 1925, it was established that when 7-dehydrocholesterol is irradiated with light, a form of a

3734:

likely serves as an alternate receptor in this pathway. The classical VDR may still play a role.

2573: 1858: 1203: 1098: 995: 896: 536: 12025:

Young AR, Morgan KA, Harrison GI, Lawrence KP, Petersen B, Wulf HC, et al. (October 2021).

9862: 7123:

Bischoff-Ferrari HA, Willett WC, Orav EJ, Oray EJ, Lips P, Meunier PJ, et al. (July 2012).

15507: 15484: 15236: 15017: 14335: 14087:"Prognostic and Therapeutic Role of Vitamin D in COVID-19: Systematic Review and Meta-analysis" 9373:"Health Canada Scientific Summary on the U. S. Health Claim Regarding Calcium and Osteoporosis" 8094: 5991:"Adaptation of calcium absorption during treatment of nutritional rickets in Nigerian children" 5211: 3191: 2612:

nmol/L) are "not consistently associated with increased benefit". Serum 25(OH)D levels above 50

1919: 1835: 1256: 1251:

A systematic review of clinical studies found an association between low vitamin D levels with

1131: 1106: 915: 14308: 9605: 9559: 4215:"Efficacy of fish intake on vitamin D status: a meta-analysis of randomized controlled trials" 3340: 3328: 3148: 2384:

Manufactured foods fortified with vitamin D include some fruit juices and fruit juice drinks,

16065: 15253: 11195:

Ross AC, Manson JE, Abrams SA, Aloia JF, Brannon PM, Clinton SK, et al. (January 2011).

9441:

Nutrient Reference Values for Australia and New Zealand Including Recommended Dietary Intakes

8717:

Shaffer JA, Edmondson D, Wasson LT, Falzon L, Homma K, Ezeokoli N, et al. (April 2014).

7846:

Beveridge LA, Struthers AD, Khan F, Jorde R, Scragg R, Macdonald HM, et al. (May 2015).

7210: 5642:

Khalid AT, Moore CG, Hall C, Olabopo F, Rozario NL, Holick MF, et al. (September 2017).

3675: 3603:

The activity of calcifediol and calcitriol can be reduced by hydroxylation at position 24 by

2750:(IOM) as of 30 November 2010, has increased the tolerable upper limit (UL) to 2,500 2747: 2604:

or negligible exposure to sunlight. The Institute found serum 25(OH)D concentrations above 30

2588: 2507: 1867: 1102: 1029: 1017: 911: 892: 732: 716: 594:

The active vitamin D metabolite, calcitriol, exerts its biological effects by binding to the

15216: 10969: 10786:

Jakobsen J, Knuthsen P (April 2014). "Stability of vitamin D in foodstuffs during cooking".

8815:

Yüksel RN, Altunsoy N, Tikir B, Cingi Külük M, Unal K, Goka S, et al. (December 2014).

7748:

Barbarawi M, Kheiri B, Zayed Y, Barbarawi O, Dhillon H, Swaid B, et al. (August 2019).

6483:

Straube S, Andrew Moore R, Derry S, McQuay HJ (January 2009). "Vitamin D and chronic pain".

2063: 2010:μg. The European Menopause and Andropause Society recommends postmenopausal women consume 15 1209:

examined one study that showed vitamin D together with insulin maintained levels of fasting

1157:

Vitamin D supplementation does not help prevent asthma attacks or alleviate their symptoms.

590:

The role of active vitamin D or calcitriol (orange) in calcium metabolism in the human body.

16070: 15878: 14934: 14714: 14438: 14259: 13611:

Goulão, Beatriz, Stewart, Fiona, Ford, John A., MacLennan, Graeme, Avenell, Alison (2018).

13610: 13419: 13329: 12772:

Holick MF, Kleiner-Bossaller A, Schnoes HK, Kasten PM, Boyle IT, DeLuca HF (October 1973).

12685: 12038: 11977:. Advances in Experimental Medicine and Biology. Vol. 1268. Springer. pp. 19–36. 10006:

DRI, Dietary reference intakes: for calcium, phosphorus, magnesium, vitamin D, and fluoride

5709: 5644:"Utility of sun-reactive skin typing and melanin index for discerning vitamin D deficiency" 4463: 4401: 4253:

Cardwell, Glenn et al. “A Review of Mushrooms as a Potential Source of Dietary Vitamin D.”

3748:

Vitamin D was discovered in 1922 following on from previous research. American researchers

3592: 3452: 3444: 3392:

enzymes for activation and inactivation, and a vitamin D binding protein (DBP) is found in

2876: 2860: 2620:

nmol/L) may be cause for concern. However, some people with serum 25(OH)D between 30 and 50

1280: 1252: 1127: 969: 876: 755: 728: 720: 677: 673: 603: 436: 117: 13877:

Kazemi A, Mohammadi V, Aghababaee SK, Golzarand M, Clark CC, Babajafari S (October 2021).

10451:. Food and Drug Administration, US Department of Health and Human Services. 18 July 2016. 9715: 5753: 5748: 1194:

A meta-analysis reported that vitamin D supplementation significantly reduced the risk of

810:

Rickets, a childhood disease, is characterized by impeded growth and soft, weak, deformed

8: 15793: 15399: 15394: 15366: 15329: 15162: 15147: 15111: 14828: 13987:

Bassatne A, Basbous M, Chakhtoura M, El Zein O, Rahme M, El-Hajj Fuleihan G (June 2021).

13540:. Advances in Experimental Medicine and Biology. Vol. 840. Springer. pp. 13–9. 13388: 11381:

Schlingmann KP, Kaufmann M, Weber S, Irwin A, Goos C, John U, et al. (August 2011).

9066:"Vitamin D and its role during pregnancy in attaining optimal health of mother and fetus" 8867:

Aghajafari F, Nagulesapillai T, Ronksley PE, Tough SC, O'Beirne M, Rabi DM (March 2013).

6832: 5241:

Munns CF, Shaw N, Kiely M, Specker BL, Thacher TD, Ozono K, et al. (February 2016).

3950: 3897: 3564: 2770: 2681: 2339: 1300: 927: 769: 642: 638: 575: 483: 346: 14304: 14263: 14247: 13989:"The link between COVID-19 and VItamin D (VIVID): A systematic review and meta-analysis" 13423: 13333: 12689: 12374: 12042: 10309: 8913:"Vitamin D supplementation during pregnancy: Updated meta-analysis on maternal outcomes" 8130:

Luong K, Nguyen LT (June 2011). "Impact of vitamin D in the treatment of tuberculosis".

7676: 7651: 5862:

Zargar AH, Mithal A, Wani AI, Laway BA, Masoodi SR, Bashir MI, et al. (June 2000).

5752: This article incorporates text from this source, which is available under the 5732: 5713: 5697: 5611: 5586: 4736: 4586: 4561: 4467: 4405: 2672:μg/day (50k IU) over several months can increase serum 25-hydroxyvitamin D levels to 150 2034:

IU) in some patients with very low vitamin D status or in case of co-morbid conditions.

16060: 15926: 15862: 15854: 15851: 15134: 14607: 14502: 14225: 14212: 14187: 14160: 14135: 14111: 14086: 14064: 14013: 13988: 13957: 13932: 13905: 13851: 13826: 13678: 13653: 13567: 13487: 13462: 13435: 13179: 12980: 12955: 12931: 12880: 12855: 12815:"24-Hydroxylation of 1,25-dihydroxyergocalciferol. An unambiguous deactivation process" 12649: 12624: 12565: 12517: 12490: 12188: 12163: 12144: 12101: 12061: 12026: 12004: 11817: 11792: 11622: 11597: 11568: 11489: 11464: 11221: 11196: 11169: 11144: 11143:

Wang L, Song Y, Manson JE, Pilz S, März W, Michaëlsson K, et al. (November 2012).

11120: 11095: 11071: 11044: 10918: 10863: 10753: 10698: 10673: 10649: 10385: 10360: 10336: 10311: 10244: 10219: 10182: 10157: 9649: 9189: 9141: 9116: 9092: 9038: 9013: 8986: 8961: 8937: 8912: 8841: 8816: 8792: 8767: 8743: 8718: 8699: 8650: 8599: 8574: 8555: 8511: 8467: 8330: 8305: 8281: 8256: 8237: 8155: 8062: 8037: 8004: 7972: 7945: 7921: 7896: 7872: 7847: 7823: 7798: 7774: 7749: 7725: 7700: 7627: 7602: 7580: 7436: 7411: 7387: 7362: 7303: 7290: 7289:

Cranney A, Horsley T, O'Donnell S, Weiler H, Puil L, Ooi D, et al. (August 2007).

7266: 7241: 7222: 7163: 7100: 7075: 7056: 7007: 6964: 6916: 6891: 6798: 6722: 6636: 6611: 6587: 6574: 6555: 6508: 6180: 6023: 5936: 5888: 5863: 5839: 5814: 5795: 5668: 5643: 5624: 5559: 5534: 5510: 5485: 5461: 5436: 5371: 5315: 5267: 5242: 5188: 5163: 5025: 5000: 4932: 4815: 4798: 4769: 4637: 4487: 4363: 4190: 4165: 3905: 3850: 3785: 3710: 3572: 3385: 3131: 3109: 3092: 2824: 2723: 2659: 2641: 2051: 2047: 1846: 1174: 1170: 1037: 1002: 965: 696: 688:

due to its impact on mineral metabolism. Consequently, vitamin D is also important for

602:

of target cells. When calcitriol binds to the VDR, it enables the receptor to act as a

595: 528: 308: 265: 241: 141: 13352: 12831: 12814: 12790: 12773: 12708: 10122: 7339: 6675: 5243:"Global Consensus Recommendations on Prevention and Management of Nutritional Rickets" 4679: 4625: 4424: 2800:) of 600–800 IU, by taking over 1000 IU, which suggests intentional supplement intake. 2410:(FDA) amended food additive regulations for milk fortification, stating that vitamin D 15321: 15010: 14894: 14869: 14328: 14275: 14229: 14217: 14188:"Vitamin D supplementation for the treatment of COVID-19: a living systematic review" 14165: 14116: 14068: 14056: 14018: 13962: 13910: 13856: 13760: 13683: 13634: 13559: 13549: 13492: 13443: 13392: 13357: 13284: 13245: 13206: 13045: 12985: 12936: 12885: 12836: 12795: 12740: 12713: 12654: 12600: 12592: 12557: 12522: 12459: 12399: 12352: 12311: 12257: 12218: 12193: 12136: 12097: 12066: 12008: 11996: 11986: 11953: 11930: 11866: 11822: 11773: 11746: 11692: 11652: 11627: 11573: 11494: 11445: 11404: 11346: 11300: 11226: 11174: 11125: 11076: 11022: 11012: 10910: 10867: 10855: 10803: 10745: 10703: 10654: 10390: 10341: 10249: 10187: 10126: 10028: 10018: 9985: 9445: 9404:. Japan Consumer Affairs Agency, Food Labelling Division. 1 June 2011. Archived from 9230: 9181: 9146: 9132: 9097: 9043: 8991: 8942: 8890: 8846: 8797: 8748: 8703: 8691: 8655: 8604: 8559: 8547: 8503: 8471: 8459: 8418: 8383: 8335: 8286: 8229: 8147: 8112: 8067: 8018: 8008: 7977: 7926: 7877: 7828: 7779: 7730: 7681: 7632: 7584: 7572: 7523: 7441: 7392: 7343: 7308: 7271: 7214: 7155: 7105: 7048: 7043: 7026: 6999: 6956: 6921: 6857: 6790: 6780: 6714: 6679: 6641: 6592: 6547: 6527: 6500: 6465: 6424: 6369: 6330: 6305: 6264: 6220: 6149: 6108: 6064: 6015: 5971: 5928: 5893: 5844: 5787: 5737: 5673: 5616: 5564: 5515: 5466: 5403: 5363: 5307: 5272: 5193: 5144: 5100: 5096: 5065: 5030: 4978: 4924: 4875: 4848: 4820: 4774: 4756: 4683: 4629: 4591: 4535: 4479: 4429: 4355: 4290: 4236: 4195: 4056: 3403: 3349: 2766: 2267: 1295:

Though hypothesized that vitamin D supplementation may be an effective treatment for

1206: 1033: 998: 634: 611: 136: 13652:

Khan SU, Khan MU, Riaz H, Valavoor S, Zhao D, Vaughan L, et al. (August 2019).

13571: 12569: 12105: 11248: 11160: 9980: 9963: 8515: 8241: 8159: 7863: 7226: 7167: 7124: 7060: 7011: 6968: 6802: 6726: 6559: 6512: 6027: 5940: 5628: 5375: 5319: 4641: 4491: 4367: 3697:

It is disputed whether these differences lead to a measurable drop in efficacy (see

1359:

Other possible agencies with claim guidance: Japan FOSHU and Australia-New Zealand.

1303:, one systematic review found no association of supplementation with body weight or 15969: 15288: 15283: 14904: 14879: 14799: 14267: 14207: 14199: 14155: 14147: 14106: 14098: 14048: 14008: 14000: 13952: 13944: 13900: 13890: 13846: 13838: 13673: 13665: 13624: 13541: 13482: 13474: 13427: 13384: 13347: 13337: 13169: 13156:

Askew FA, Bourdillon RB, Bruce HM, Callow RK, St. L. Philpot J, Webster TA (1932).

13138: 12975: 12967: 12926: 12916: 12875: 12867: 12826: 12785: 12703: 12693: 12644: 12636: 12549: 12512: 12502: 12449: 12389: 12342: 12301: 12183: 12175: 12148: 12128: 12093: 12056: 12046: 11978: 11920: 11889: 11856: 11812: 11804: 11736: 11617: 11609: 11563: 11553: 11484: 11476: 11435: 11394: 11290: 11216: 11208: 11164: 11156: 11115: 11107: 11066: 11056: 11004: 10922: 10902: 10845: 10837: 10799: 10795: 10757: 10737: 10693: 10685: 10644: 10634: 10603: 10380: 10372: 10331: 10323: 10239: 10231: 10177: 10169: 10118: 10061:. US Department of Agriculture, Agricultural Research Service. 2014. Archived from 10010: 9975: 9795: 9629: 9619: 9583: 9573: 9297: 9263: 9220: 9193: 9173: 9136: 9128: 9087: 9077: 9033: 9029: 9025: 8981: 8973: 8932: 8924: 8880: 8836: 8828: 8787: 8779: 8738: 8730: 8683: 8645: 8635: 8594: 8590: 8586: 8539: 8495: 8449: 8410: 8379: 8375: 8371: 8325: 8317: 8276: 8272: 8268: 8219: 8139: 8104: 8057: 8049: 8000: 7967: 7957: 7916: 7908: 7867: 7859: 7818: 7810: 7769: 7761: 7720: 7712: 7671: 7663: 7622: 7614: 7562: 7554: 7515: 7431: 7427: 7423: 7382: 7374: 7335: 7298: 7261: 7253: 7206: 7147: 7139: 7095: 7091: 7087: 7038: 6995: 6991: 6948: 6911: 6903: 6847: 6772: 6706: 6671: 6631: 6623: 6582: 6539: 6492: 6455: 6414: 6295: 6254: 6210: 6176: 6139: 6098: 6054: 6005: 5963: 5920: 5883: 5875: 5834: 5830: 5826: 5779: 5727: 5717: 5663: 5655: 5606: 5598: 5554: 5546: 5505: 5497: 5456: 5448: 5355: 5299: 5262: 5254: 5183: 5175: 5134: 5092: 5057: 5020: 5012: 4968: 4936: 4916: 4810: 4764: 4748: 4675: 4621: 4581: 4577: 4573: 4525: 4471: 4419: 4409: 4347: 4280: 4226: 4185: 4181: 4177: 4118:. Office of Dietary Supplements, US National Institutes of Health. 12 August 2022. 3911:

Some preliminary studies link low vitamin D levels with disease later in life. One

3813: 3753: 3472: 3248:

in an organic solvent takes about 12 days to complete. The conversion of previtamin

2400: 2385: 740: 623: 312: 14579: 14574: 14569: 14052: 14004: 13931:

Petrelli F, Luciani A, Perego G, Dognini G, Colombelli PL, Ghidini A (July 2021).

13129:

Rosenheim O, King H (1932). "The Ring-system of sterols and bile acids. Part II".

8543: 8224: 8207: 7558: 6403:"Previous milk consumption is associated with greater bone density in young women" 5799: 4701: 3376:

Vitamin D can be synthesized only by a photochemical process. Its production from

253: 16044: 15931: 15913: 15613: 15246: 15041: 14909: 14466: 14451: 13278: 13239: 13198: 13037: 12774:"1,24,25-Trihydroxyvitamin D3. A metabolite of vitamin D3 effective on intestine" 12732: 12674:"Genetic evidence that the human CYP2R1 enzyme is a key vitamin D 25-hydroxylase" 12251: 12214:

The Vitamin D Solution: A 3-Step Strategy to Cure Our Most Common Health Problems

12212: 11686: 11515:(Press release). Food and Drug Administration (FDA). 15 June 2010. Archived from 10741: 10107:

in Cladina spp. over a latitudinal gradient: possible correlation with UV levels"

8783: 8734: 8321: 8143: 7765: 6363: 6324: 5397: 4869: 3833: 3765: 3477: 3398: 3226: 2188: 1195: 1065: 976: 865: 864:

ng/mL. Although the effects of osteomalacia are thought to contribute to chronic

724: 689: 657: 607: 431: 339: 226: 178: 74: 31: 15820: 14557: 14552: 14547: 14542: 13948: 13588:. National Cancer Institute, US National Institutes of Health. 21 October 2013. 13510: 12871: 11982: 11275: 11008: 8928: 8255:

Williamson A, Martineau AR, Sheikh A, Jolliffe D, Griffiths CJ (February 2023).

7814: 7667: 6952: 5696:

Ben-Eltriki M, Gayle EJ, Paras JM, Nyame-Addo L, Chhabra M, Deb S (April 2024).

4475: 3498:

Vitamin D is carried via the blood to the liver, where it is converted into the

15956: 15765: 15734: 15706: 15651: 15263: 15194: 14979: 14899: 14612: 14425: 13895: 13878: 13842: 13478: 13322:

Proceedings of the National Academy of Sciences of the United States of America

12678:

Proceedings of the National Academy of Sciences of the United States of America

12031:

Proceedings of the National Academy of Sciences of the United States of America

11741: 11728: 11596:

Rooney MR, Harnack L, Michos ED, Ogilvie RP, Sempos CT, Lutsey PL (June 2017).

11422:

De Paolis E, Scaglione GL, De Bonis M, Minucci A, Capoluongo E (October 2019).

11045:"Plausible ergogenic effects of vitamin D on athletic performance and recovery" 9560:

EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) (29 June 2016).

8499: 7962: 6766: 6762: 6496: 6241:

Dunnigan MG, Henderson JB, Hole DJ, Barbara Mawer E, Berry JL (December 2005).

5967: 5815:"Interventions for the prevention of nutritional rickets in term born children" 5587:"Effect of race and genetics on vitamin D metabolism, bone and vascular health" 5550: 4394:

Proceedings of the National Academy of Sciences of the United States of America

3878: 3822: 3805: 3749: 3424: 3280: 2697: 2656: 2396: 1834:

Various institutions have proposed different recommendations for the amount of

1110: 926:

and metabolic syndrome, falls and physical performance, immune functioning and

904: 900: 887:

Supplementation with vitamin D is a reliable method for preventing or treating

830:

Rickets was formerly a major public health problem among the US population. In

685: 478: 406: 386: 234: 129: 27: 15546: 14203: 13014: 12553: 12394: 12132: 11646: 11061: 10906: 10841: 9405: 8640: 8623: 8304:

Del Pinto R, Pietropaoli D, Chandar AK, Ferri C, Cominelli F (November 2015).

8038:"Vitamin D and immune regulation: antibacterial, antiviral, anti-inflammatory" 7519: 6710: 6543: 6300: 6283: 6215: 6198: 6059: 6042: 6010: 5924: 5486:"Special considerations for vitamin D in the south Asian population in the UK" 5452: 5303: 4973: 4956: 3487: 2900:

Click on genes, proteins and metabolites below to link to respective articles.

2803:

Over 3% of the population exceeds the NIH daily tolerable upper intake level (

16054: 15775: 15551: 14748: 14738: 14723: 14443: 14279: 14136:"Vitamin D supplementation, COVID-19 & Disease Severity: A meta-analysis" 14102: 13731: 13613:"Cancer and vitamin D supplementation: a systematic review and meta-analysis" 12596: 12179: 11808: 11527: 10543: 10507: 10471: 10435: 10297: 10081: 9848: 9774: 9676: 9624: 9607: 9578: 9561: 9359: 9302: 9267: 8832: 7543: 7493: 7378: 6419: 6402: 5501: 4760: 4285: 4268: 3912: 3789: 3757: 3584: 3365: 3195: 3161: 2844: 2685: 2569: 2562: 2119: 2043: 1930: 1349: 1284: 284: 249: 14386: 14381: 14151: 13431: 13142: 12698: 12673: 12507: 12051: 11861: 11844: 11295: 9225: 9208: 8960:

Roth DE, Leung M, Mesfin E, Qamar H, Watterworth J, Papp E (November 2017).

7716: 7257: 6573:

Chung M, Balk EM, Brendel M, Ip S, Lau J, Lee J, et al. (August 2009).

5602: 5179: 4530: 4513: 4231: 4214: 2042:

Although vitamin D is present naturally in only a few foods, it is commonly

245: 26:

This article is about the family of D-"vitamins". For individual forms, see

15979: 15974: 15941: 15903: 15888: 15558: 15494: 15479: 15442: 15389: 15356: 15096: 15063: 14954: 14874: 14833: 14786: 14753: 14733: 14728: 14589: 14517: 14507: 14497: 14355: 14221: 14169: 14120: 14060: 14022: 13966: 13914: 13860: 13687: 13638: 13563: 13496: 13174: 13157: 13009: 12989: 12940: 12889: 12717: 12658: 12604: 12561: 12526: 12403: 12356: 12197: 12140: 12070: 12000: 11934: 11925: 11908: 11870: 11826: 11656: 11631: 11613: 11577: 11498: 11449: 11440: 11423: 11408: 11304: 11276:"Vitamin D supplementation, 25-hydroxyvitamin D concentrations, and safety" 11230: 11178: 11129: 11080: 11026: 10914: 10859: 10807: 10749: 10707: 10658: 10394: 10345: 10327: 10310:

de Lourdes Samaniego-Vaesken M, Alonso-Aperte E, Varela-Moreiras G (2012).

10253: 10191: 10130: 10032: 9989: 9234: 9185: 9150: 9101: 9047: 8995: 8946: 8894: 8850: 8801: 8768:"Vitamin D, cognition, and dementia: a systematic review and meta-analysis" 8752: 8695: 8659: 8608: 8551: 8507: 8463: 8422: 8387: 8339: 8290: 8233: 8151: 8116: 8071: 8022: 7981: 7930: 7881: 7832: 7783: 7734: 7685: 7636: 7576: 7527: 7445: 7396: 7347: 7312: 7275: 7218: 7159: 7109: 7052: 7003: 6960: 6925: 6861: 6794: 6718: 6683: 6645: 6596: 6551: 6504: 6469: 6428: 6268: 6243:"Meat consumption reduces the risk of nutritional rickets and osteomalacia" 6224: 6068: 6019: 5975: 5932: 5897: 5879: 5848: 5791: 5783: 5741: 5677: 5620: 5568: 5519: 5470: 5367: 5311: 5276: 5197: 5148: 5069: 5061: 5034: 4982: 4928: 4778: 4687: 4633: 4595: 4539: 4294: 4240: 4199: 3901: 3551:

D). The conversion of calcifediol to calcitriol is catalyzed by the enzyme

3537: 3513: 3230: 3156: 1135: 1097:

Vitamin D supplementation is not associated with a reduced risk of stroke,

1049: 961: 931: 919: 872: 852: 847: 843: 681: 599: 571: 543: 464: 354: 264:. Cholecalciferol and ergocalciferol can also be obtained through diet and 159: 113: 109: 13629: 13612: 13447: 13396: 13361: 13342: 13317: 12840: 12799: 12463: 12315: 11777: 11750: 11399: 11382: 10220:"Photobiology of vitamin D in mushrooms and its bioavailability in humans" 10173: 8687: 8414: 7143: 7125:"A pooled analysis of vitamin D dose requirements for fracture prevention" 6309: 6153: 6112: 5989:

Oramasionwu GE, Thacher TD, Pam SD, Pettifor JM, Abrams SA (August 2008).

5864:"Pseudovitamin D deficiency rickets—a report from the Indian subcontinent" 5104: 4824: 4483: 4433: 4414: 4385: 4359: 1891:

and supplements, and assumes that calcium requirements are being met. The

15893: 15742: 15719: 15221: 15124: 14886: 14743: 14564: 14456: 13545: 13513:. Office of Dietary Supplements, US National Institutes of Health. 2018. 12813:

Horst RL, Reinhardt TA, Ramberg CF, Koszewski NJ, Napoli JL (July 1986).

12640: 12491:"Vitamin D in plants: a review of occurrence, analysis, and biosynthesis" 11893: 11480: 11212: 11111: 10689: 9588: 8108: 7999:. Vitamins & Hormones. Vol. 86. Academic Press. pp. 23–62. 7912: 5722: 5359: 5258: 5139: 5122: 3809: 3777: 3743: 3591:, modulating body defenses against microbial invaders by stimulating the 3587:. When synthesized by monocyte-macrophages, calcitriol acts locally as a 3580: 3533: 3502: 3481: 3336: 3332: 3187: 2840: 2762:

IU per day for ages 9–71+ years (including pregnant or lactating women).

2665:

240 μg/day (10k IU), over 5 months have been shown not to cause toxicity.

2576:

increases when blood levels of vitamin D are lowest in a range of 8 to 24

2392: 1886:

for vitamin D issued in 2010 by the Institute of Medicine (IoM) (renamed

1199: 1005:, but not independently can improve healing in children with nutritional 736: 650: 567: 335: 319: 277: 206: 203: 14084: 12306: 12289: 11465:"Vitamin D-Mediated Hypercalcemia: Mechanisms, Diagnosis, and Treatment" 10850: 7567: 6259: 6242: 6144: 6127: 6103: 6086: 5659: 5396:

Brown JE, Isaacs J, Krinke B, Lechtenberg E, Murtaugh M (28 June 2013).

4752: 2584:

nmol/L), although results among the studies analyzed were inconsistent.

15984: 15960: 15917: 15908: 15898: 15770: 15656: 15306: 15258: 15187: 15182: 14824: 14816: 14809: 14773: 14766: 14693: 14639: 14621: 14537: 14512: 14486: 14461: 14420: 14185: 13439: 12971: 12454: 10672:

Biancuzzo RM, Clarke N, Reitz RE, Travison TG, Holick MF (March 2013).

10235: 9788:"Daily Value Reference of the Dietary Supplement Label Database (DSLD)" 9634: 9606:

EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) (2012).

8436:

Zhang Y, Tan H, Tang J, Li J, Chong W, Hai Y, et al. (July 2020).

8053: 7618: 4734: 4351: 3954: 3714: 3521: 3506: 3499: 3492: 3393: 3183: 2884: 2832: 2447: 2388: 2351: 2090: 1045: 1016:(FDA) has required manufacturers to declare the amount of vitamin D on 972:. Taking extra vitamin D, however, does not appear to change the risk. 811: 661: 646: 559: 491: 410: 390: 323: 304: 261: 60: 43: 39: 35: 14271: 12921: 12904: 12347: 12330: 11558: 11541: 11505: 10639: 10622: 10607: 10376: 10059:"Search, National Nutrient Database for Standard Reference Release 27" 9177: 9082: 9065: 8977: 8885: 8868: 8454: 8437: 8036:

Bishop E, Ismailova A, Dimeloe SK, Hewison M, White JH (August 2020).

7151: 6907: 6627: 5161: 5016: 4920: 4847:. London, United Kingdom: Academic Press (Elsevier). pp. 93–114. 4166:"Vitamin D metabolism, mechanism of action, and clinical applications" 2395:-based beverages, certain cheese and cheese products, flour products, 191: 15573: 15502: 15384: 15296: 15231: 15157: 14929: 14921: 14838: 14804: 14630: 14599: 14529: 14396: 14373: 13669: 13183: 12672:

Cheng JB, Levine MA, Bell NH, Mangelsdorf DJ, Russell DW (May 2004).

10098: 10062: 9889:"Australian Health Survey: Biomedical Results for Nutrients, 2011–12" 9608:"Scientific Opinion on the Tolerable Upper Intake Level of vitamin D" 9115:

Bi WG, Nuyt AM, Weiler H, Leduc L, Santamaria C, Wei SQ (July 2018).

8911:

Palacios C, De-Regil LM, Lombardo LK, Peña-Rosas JP (November 2016).

8866: 8177:"SACN rapid review: Vitamin D and acute respiratory tract infections" 7650:

Seraphin G, Rieger S, Hewison M, Capobianco E, Lisse TS (July 2023).

6460: 6444:"High prevalence of vitamin D inadequacy and implications for health" 6443: 4386:"Identification of 1,25-dihydroxycholecalciferol, a form of vitamin D 3761: 3361: 2601: 1260: 1210: 1165:

Low levels of vitamin D are associated with two major forms of human

704: 669: 619: 586: 331: 218: 214: 153: 13535: 12771: 10823:"A global representation of vitamin D status in healthy populations" 9064:

Wagner CL, Taylor SN, Dawodu A, Johnson DD, Hollis BW (March 2012).

8573:

Brophy S, Davies H, Mannan S, Brunt H, Williams R (September 2011).

6852: 6526:

Gaikwad M, Vanlint S, Mittinity M, Moseley GL, Stocks N (May 2017).

6401:

Teegarden D, Lyle RM, Proulx WR, Johnston CC, Weaver CM (May 1999).

4735:

Alayed Albarri EM, Sameer Alnuaimi A, Abdelghani D (4 August 2022).

4212: 3356:

The skin consists of two primary layers: the inner layer called the

2823:

The main symptoms of vitamin D overdose are hypercalcemia including

2807:) of 4000 IU, above which level the risk of toxic effects increases. 1036:, although the strength of the associations was classified as weak. 991:

ng/mL with no additional benefits seen in levels beyond this point.

15724: 15623: 15605: 15563: 15541: 15464: 15456: 15437: 15419: 15348: 15226: 15119: 15081: 14707: 11539: 10218:

Keegan RJ, Lu Z, Bogusz JM, Williams JE, Holick MF (January 2013).

7699:

Keum N, Lee DH, Greenwood DC, Manson JE, Giovannucci E (May 2019).

7603:"Vitamin D and Clinical Cancer Outcomes: A Review of Meta-Analyses" 6776: 5120: 3908:, and other medical conditions remains under preliminary research. 3893: 3588: 3576: 2848: 2836: 2828: 2778: 2359: 2227: 2162: 2132: 1304: 1225:

A meta-analysis of observational studies showed that children with

1061: 923: 856: 788: 257: 69: 13876: 12328: 11793:"History of the discovery of vitamin D and its active metabolites" 11540:

Olmos-Ortiz A, Avila E, Durand-Carbajal M, Díaz L (January 2015).

10014: 9961: 8910: 7895:

Zhang D, Cheng C, Wang Y, Sun H, Yu S, Xue Y, et al. (2020).

7409: 7291:"Effectiveness and safety of vitamin D in relation to bone health" 6240: 6087:"An epidemiological model of privational rickets and osteomalacia" 5698:"Vitamin D in Melanoma: Potential Role of Cytochrome P450 Enzymes" 3380:

would have started very early in the evolution of life around the

3178:

The transformation that converts 7-dehydrocholesterol to vitamin D

2692:

Idiopathic infantile hypercalcemia is caused by a mutation of the

1220: 1068:(CYP) enzymes to become active and bind to the VDR. Specifically, 444: 15628: 15595: 15590: 15582: 15469: 15404: 15275: 15033: 14391: 14351: 14320: 13730: