Vitamin D

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For other uses, see Vitamin D (disambiguation). Vitamin D_sentence_0

This article is about the family of vitamers. Vitamin D_sentence_1

For individual forms, see ergocalciferol, cholecalciferol, vitamin D4, and vitamin D5. Vitamin D_sentence_2

Vitamin D_table_infobox_0

Vitamin DVitamin D_header_cell_0_0_0
Class identifiersVitamin D_header_cell_0_1_0
SynonymsVitamin D_header_cell_0_2_0 CalciferolsVitamin D_cell_0_2_1
UseVitamin D_header_cell_0_3_0 Rickets, osteoporosis, vitamin D deficiencyVitamin D_cell_0_3_1
ATC codeVitamin D_header_cell_0_4_0 A11CCVitamin D_cell_0_4_1
Biological targetVitamin D_header_cell_0_5_0 vitamin D receptorVitamin D_cell_0_5_1
Clinical dataVitamin D_header_cell_0_6_0
Drugs.comVitamin D_header_cell_0_7_0 Vitamin D_cell_0_7_1
External linksVitamin D_header_cell_0_8_0
MeSHVitamin D_header_cell_0_9_0 Vitamin D_cell_0_9_1

Vitamin D is a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, and many other biological effects. Vitamin D_sentence_3

In humans, the most important compounds in this group are vitamin D3 (also known as cholecalciferol) and vitamin D2 (ergocalciferol). Vitamin D_sentence_4

The major natural source of the vitamin is synthesis of cholecalciferol in the lower layers of skin epidermis through a chemical reaction that is dependent on sun exposure (specifically UVB radiation). Vitamin D_sentence_5

Cholecalciferol and ergocalciferol can be ingested from the diet and from supplements. Vitamin D_sentence_6

Only a few foods, such as the flesh of fatty fish, naturally contain significant amounts of vitamin D. In the U.S. and other countries, cow's milk and plant-derived milk substitutes are fortified with vitamin D, as are many breakfast cereals. Vitamin D_sentence_7

Mushrooms exposed to ultraviolet light contribute useful amounts of vitamin D. Dietary recommendations typically assume that all of a person's vitamin D is taken by mouth, as sun exposure in the population is variable and recommendations about the amount of sun exposure that is safe are uncertain in view of the skin cancer risk. Vitamin D_sentence_8

Vitamin D from the diet, or from skin synthesis, is biologically inactive. Vitamin D_sentence_9

It is activated by two protein enzyme hydroxylation steps, the first in the liver and the second in the kidneys. Vitamin D_sentence_10

As vitamin D can be synthesized in adequate amounts by most mammals if exposed to sufficient sunlight, it is not essential, so technically not a vitamin. Vitamin D_sentence_11

Instead it can be considered a hormone, with activation of the vitamin D pro-hormone resulting in the active form, calcitriol, which then produces effects via a nuclear receptor in multiple locations. Vitamin D_sentence_12

Cholecalciferol is converted in the liver to calcifediol (25-hydroxycholecalciferol); ergocalciferol is converted to 25-hydroxyergocalciferol. Vitamin D_sentence_13

These two vitamin D metabolites (called 25-hydroxyvitamin D or 25(OH)D) are measured in serum to determine a person's vitamin D status. Vitamin D_sentence_14

Calcifediol is further hydroxylated by the kidneys to form calcitriol (also known as 1,25-dihydroxycholecalciferol), the biologically active form of vitamin D. Calcitriol circulates as a hormone in the blood, having a major role regulating the concentration of calcium and phosphate, and promoting the healthy growth and remodeling of bone. Vitamin D_sentence_15

Calcitriol also has other effects, including some on cell growth, neuromuscular and immune functions, and reduction of inflammation. Vitamin D_sentence_16

Vitamin D has a significant role in calcium homeostasis and metabolism. Vitamin D_sentence_17

Its discovery was due to effort to find the dietary substance lacking in children with rickets (the childhood form of osteomalacia). Vitamin D_sentence_18

Vitamin D supplements are given to treat or to prevent osteomalacia and rickets. Vitamin D_sentence_19

The evidence for other health effects of vitamin D supplementation in the general population is inconsistent. Vitamin D_sentence_20

The effect of vitamin D supplementation on mortality is not clear, with one meta-analysis finding a small decrease in mortality in elderly people, and another concluding no clear justification exists for recommending supplementation for preventing many diseases, and that further research of similar design is not needed in these areas. Vitamin D_sentence_21

Types Vitamin D_section_0

Vitamin D_table_general_1

NameVitamin D_header_cell_1_0_0 Chemical compositionVitamin D_header_cell_1_0_1 StructureVitamin D_header_cell_1_0_2
Vitamin D1Vitamin D_header_cell_1_1_0 Mixture of molecular compounds of ergocalciferol with lumisterol, 1:1Vitamin D_cell_1_1_1 Vitamin D_cell_1_1_2
Vitamin D2Vitamin D_header_cell_1_2_0 ergocalciferol (made from ergosterol)Vitamin D_cell_1_2_1 Vitamin D_cell_1_2_2
Vitamin D3Vitamin D_header_cell_1_3_0 cholecalciferol (made from 7-dehydrocholesterol in the skin).Vitamin D_cell_1_3_1 Vitamin D_cell_1_3_2
Vitamin D4Vitamin D_header_cell_1_4_0 22-dihydroergocalciferolVitamin D_cell_1_4_1 Vitamin D_cell_1_4_2
Vitamin D5Vitamin D_header_cell_1_5_0 sitocalciferol (made from 7-dehydrositosterol)Vitamin D_cell_1_5_1 Vitamin D_cell_1_5_2

Several forms (vitamers) of vitamin D exist. Vitamin D_sentence_22

The two major forms are vitamin D2 or ergocalciferol, and vitamin D3 or cholecalciferol; vitamin D without a subscript refers to either D2 or D3 or both. Vitamin D_sentence_23

These are known collectively as calciferol. Vitamin D_sentence_24

Vitamin D2 was chemically characterized in 1931. Vitamin D_sentence_25

In 1935, the chemical structure of vitamin D3 was established and proven to result from the ultraviolet irradiation of 7-dehydrocholesterol. Vitamin D_sentence_26

Chemically, the various forms of vitamin D are secosteroids, i.e., steroids in which one of the bonds in the steroid rings is broken. Vitamin D_sentence_27

The structural difference between vitamin D2 and vitamin D3 is the side chain of D2 that contains a double bond between carbons 22 and 23, and a methyl group on carbon 24. Vitamin D_sentence_28

Biology Vitamin D_section_1

The active vitamin D metabolite calcitriol mediates its biological effects by binding to the vitamin D receptor (VDR), which is principally located in the nuclei of target cells. Vitamin D_sentence_29

The binding of calcitriol to the VDR allows the VDR to act as a transcription factor that modulates the gene expression of transport proteins (such as TRPV6 and calbindin), which are involved in calcium absorption in the intestine. Vitamin D_sentence_30

The vitamin D receptor belongs to the nuclear receptor superfamily of steroid/thyroid hormone receptors, and VDRs are expressed by cells in most organs, including the brain, heart, skin, gonads, prostate, and breast. Vitamin D_sentence_31

VDR activation in the intestine, bone, kidney, and parathyroid gland cells leads to the maintenance of calcium and phosphorus levels in the blood (with the assistance of parathyroid hormone and calcitonin) and to the maintenance of bone content. Vitamin D_sentence_32

One of the most important roles of vitamin D is to maintain skeletal calcium balance by promoting calcium absorption in the intestines, promoting bone resorption by increasing osteoclast number, maintaining calcium and phosphate levels for bone formation, and allowing proper functioning of parathyroid hormone to maintain serum calcium levels. Vitamin D_sentence_33

Vitamin D deficiency can result in lower bone mineral density and an increased risk of reduced bone density (osteoporosis) or bone fracture because a lack of vitamin D alters mineral metabolism in the body. Vitamin D_sentence_34

Thus, vitamin D is also critical for bone remodeling through its role as a potent stimulator of bone resorption. Vitamin D_sentence_35

The VDR regulates cell proliferation and differentiation. Vitamin D_sentence_36

Vitamin D also affects the immune system, and VDRs are expressed in several white blood cells, including monocytes and activated T and B cells. Vitamin D_sentence_37

In vitro, vitamin D increases expression of the tyrosine hydroxylase gene in adrenal medullary cells, and affects the synthesis of neurotrophic factors, nitric oxide synthase, and glutathione. Vitamin D_sentence_38

Vitamin D receptor expression decreases with age and findings suggest that vitamin D is directly related to muscle strength, mass and function, all being important factors to an athlete's performance. Vitamin D_sentence_39

Deficiency Vitamin D_section_2

Main article: Vitamin D deficiency Vitamin D_sentence_40

An estimated one billion people worldwide are either vitamin D insufficient or deficient. Vitamin D_sentence_41

Vitamin D deficiency is widespread in the European population. Vitamin D_sentence_42

A diet with insufficient vitamin D in conjunction with inadequate sun exposure causes vitamin D deficiency. Vitamin D_sentence_43

Severe vitamin D deficiency in children causes rickets, a softening and weakening of bones, which is a rare disease in the developed world. Vitamin D_sentence_44

Vitamin D deficiency is found worldwide in the elderly and remains common in children and adults. Vitamin D_sentence_45

Deficiency results in impaired bone mineralization and bone damage which leads to bone-softening diseases, including rickets in children and osteomalacia in adults. Vitamin D_sentence_46

Low blood calcifediol (25-hydroxy-vitamin D) can result from avoiding the sun. Vitamin D_sentence_47

Being deficient in vitamin D can cause intestinal absorption of dietary calcium to fall to 15%. Vitamin D_sentence_48

When not deficient, an individual usually absorbs between 60-80%. Vitamin D_sentence_49

Bone health Vitamin D_section_3

Rickets Vitamin D_section_4

Main article: Rickets Vitamin D_sentence_50

Rickets, a childhood disease, is characterized by impeded growth and soft, weak, deformed long bones that bend and bow under their weight as children start to walk. Vitamin D_sentence_51

Rickets typically appears between 3 and 18 months of age. Vitamin D_sentence_52

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. Vitamin D_sentence_53

This condition is characterized by bow legs, which can be caused by calcium or phosphorus deficiency, as well as a lack of vitamin D; today, it is largely found in low-income countries in Africa, Asia, or the Middle East and in those with genetic disorders such as pseudovitamin D deficiency rickets. Vitamin D_sentence_54

Maternal vitamin D deficiency may cause overt bone disease from before birth and impairment of bone quality after birth. Vitamin D_sentence_55

Nutritional rickets exists in countries with intense year-round sunlight such as Nigeria and can occur without vitamin D deficiency. Vitamin D_sentence_56

Although rickets and osteomalacia are now rare in the UK, outbreaks have happened in some immigrant communities in which osteomalacia sufferers included women with seemingly adequate daylight outdoor exposure wearing Western clothing. Vitamin D_sentence_57

Having darker skin and reduced exposure to sunshine did not produce rickets unless the diet deviated from a Western omnivore pattern characterized by high intakes of meat, fish, and eggs, and low intakes of high-extraction cereals. Vitamin D_sentence_58

The dietary risk factors for rickets include abstaining from animal foods. Vitamin D_sentence_59

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. Vitamin D_sentence_60

In sunny countries such as Nigeria, South Africa, and Bangladesh, where rickets occurs 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. Vitamin D_sentence_61

Rickets was formerly a major public health problem among the US population; in Denver, where ultraviolet rays are about 20% stronger than at sea level on the same latitude, almost two-thirds of 500 children had mild rickets in the late 1920s. Vitamin D_sentence_62

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. Vitamin D_sentence_63

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. Vitamin D_sentence_64

Osteoporosis and osteomalacia Vitamin D_section_5

Main articles: Osteoporosis and Osteomalacia Vitamin D_sentence_65

Osteomalacia is a disease in adults that results from vitamin D deficiency. Vitamin D_sentence_66

Characteristics of this disease are softening of the bones, leading to bending of the spine, bowing of the legs, proximal muscle weakness, bone fragility, and increased risk for fractures. Vitamin D_sentence_67

Osteomalacia reduces calcium absorption and increases calcium loss from bone, which increases the risk for bone fractures. Vitamin D_sentence_68

Osteomalacia is usually present when 25-hydroxyvitamin D levels are less than about 10 ng/mL. Vitamin D_sentence_69

Although the effects of osteomalacia are thought to contribute to chronic musculoskeletal pain, there is no persuasive evidence of lower vitamin D levels in chronic pain sufferers or that supplementation alleviates chronic nonspecific musculoskeletal pain. Vitamin D_sentence_70

Skin pigmentation Vitamin D_section_6

Dark-skinned people living in temperate climates have been shown to have low vitamin D levels but the significance of this is not certain. Vitamin D_sentence_71

Dark-skinned people are less efficient at making vitamin D because melanin in the skin hinders vitamin D synthesis. Vitamin D_sentence_72

Vitamin D deficiency is common in Hispanic and African-Americans in the United States, with levels dropping significantly in the winter. Vitamin D_sentence_73

This is due to the levels of melanin in the skin, as it acts as a natural protectant from sun exposure. Vitamin D_sentence_74

Use of supplements Vitamin D_section_7

Supplementation with vitamin D is a reliable method for preventing or treating rickets. Vitamin D_sentence_75

The effects of vitamin D supplementation on non-skeletal health are uncertain. Vitamin D_sentence_76

A 2013 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_sentence_77

Vitamin D supplements do not alter the outcomes for myocardial infarction, stroke or cerebrovascular disease, cancer, bone fractures or knee osteoarthritis. Vitamin D_sentence_78

Low vitamin D levels may result from disease rather than cause disease. Vitamin D_sentence_79

A United States Institute of Medicine (IOM) report states: "Outcomes related to cancer, cardiovascular disease and hypertension, and diabetes and metabolic syndrome, falls and physical performance, immune functioning and autoimmune disorders, infections, neuropsychological functioning, and preeclampsia could not be linked reliably with calcium or vitamin D intake and were often conflicting." Vitamin D_sentence_80

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. Vitamin D_sentence_81

Members of the IOM panel maintain that they used a "standard procedure for dietary recommendations" and that the report is solidly based on the data. Vitamin D_sentence_82

Research on vitamin D supplements, including large-scale clinical trials, is continuing. Vitamin D_sentence_83

Mortality, all-causes Vitamin D_section_8

Vitamin D3 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. Vitamin D_sentence_84

Other forms (vitamin D2, alfacalcidol, and calcitriol) do not appear to have any beneficial effects with regard to the risk of death. Vitamin D_sentence_85

High blood levels appear to be associated with a lower risk of death, but it is unclear if supplementation can result in this benefit. Vitamin D_sentence_86

Both an excess and a deficiency in vitamin D appear to cause abnormal functioning and premature aging. Vitamin D_sentence_87

The relationship between serum calcifediol level and all-cause mortality is parabolic. Vitamin D_sentence_88

Harm from vitamin D appears to occur at a lower vitamin D level in the black population than in the white population. Vitamin D_sentence_89

Bone health Vitamin D_section_9

In general, no good evidence supports the commonly held belief that vitamin D supplements can help prevent osteoporosis. Vitamin D_sentence_90

Its general use for prevention of this disease in those without vitamin D deficiency is thus likely not needed. Vitamin D_sentence_91

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. Vitamin D_sentence_92

A study found that supplementation with 800 UI or more daily, in those older than 65 years was "somewhat favorable in the prevention of hip fracture and non-vertebral fracture". Vitamin D_sentence_93

The effect is small or none for people living independently. Vitamin D_sentence_94

Low serum vitamin D levels have been associated with falls, and low bone mineral density. Vitamin D_sentence_95

Taking extra vitamin D, however, does not appear to change the risk. Vitamin D_sentence_96

Athletes who are vitamin D deficient are at an increased risk of stress fractures and/or major breaks, particularly those engaging in contact sports. Vitamin D_sentence_97

The greatest benefit with supplementation is seen in athletes who are deficient (25(OH)D serum levels <30 ng/mL), or severely deficient (25(OH)D serum levels <25 ng/mL). Vitamin D_sentence_98

Incremental decreases in risks are observed with rising serum 25(OH)D concentrations plateauing at 50 ng/mL with no additional benefits seen in levels beyond this point. Vitamin D_sentence_99

Because it found mounting evidence for a benefit to bone health, though it had not found good evidence of other benefits, the US Food and Drug Administration (FDA) has required manufacturers to declare the amount of vitamin D on nutrition facts labels, as "nutrients of public health significance", since May 2016. Vitamin D_sentence_100

By a proposed deadline extension, small manufacturers with less than $10 million in annual food sales will have to comply by January 1, 2021, while larger ones have to comply by January 1, 2020. Vitamin D_sentence_101

Manufacturers of single-ingredient sugars such as honey and maple syrup and certain cranberry products have until July 1, 2021, to make the changes. Vitamin D_sentence_102

Cancer Vitamin D_section_10

Vitamin D supplements have been widely marketed for their claimed anti­cancer properties. Vitamin D_sentence_103

Associations have been shown in observational studies between low vitamin D levels and the risk of development of certain cancers. Vitamin D_sentence_104

It is unclear, however, if taking additional vitamin D in the diet or as supplements affects the risk of cancer. Vitamin D_sentence_105

Reviews have described the evidence as being "inconsistent, inconclusive as to causality, and insufficient to inform nutritional requirements" and "not sufficiently robust to draw conclusions". Vitamin D_sentence_106

One 2014 review found that supplements had no significant effect on cancer risk. Vitamin D_sentence_107

Another 2014 review concluded that vitamin D3 may decrease the risk of death from cancer (one fewer death in 150 people treated over 5 years), but concerns with the quality of the data were noted. Vitamin D_sentence_108

Insufficient evidence existed to recommend vitamin D supplements for all people with cancer, although some evidence suggested that low vitamin D may be associated with a worse outcome for some cancers, and that higher 25-hydroxy vitamin D levels at the time of diagnosis were associated with better outcomes. Vitamin D_sentence_109

A 2020 systematic review and meta-analysis in people with colorectal cancer found evidence of a clinically meaningful benefit from vitamin D supplementation on outcomes, including survival, although the analysis had limitations. Vitamin D_sentence_110

Cardiovascular disease Vitamin D_section_11

Taking vitamin D supplements does not meaningfully reduce the risk of stroke, cerebrovascular disease, cardial infarction, or ischemic heart disease. Vitamin D_sentence_111

Supplementation may have no effect on blood pressure. Vitamin D_sentence_112

Immune system Vitamin D_section_12

Infectious diseases Vitamin D_section_13

In general, vitamin D functions to activate the innate and dampen the adaptive immune systems with antibacterial, antiviral and anti-inflammatory effects. Vitamin D_sentence_113

Deficiency has been linked to increased risk or severity of viral infections, including HIV and COVID-19. Vitamin D_sentence_114

Low levels of vitamin D appear to be a risk factor for tuberculosis, and historically it was used as a treatment. Vitamin D_sentence_115

Supplementation slightly decreases the risk and severity of acute respiratory tract infections, and also the exacerbation of asthma. Vitamin D_sentence_116

There is no evidence for vitamin D affecting respiratory infections in children under five years of age. Vitamin D_sentence_117

Vitamin D supplementation substantially reduces the rate of moderate or severe exacerbations of COPD in people with baseline 25(OH)D levels under 25nmol/L but not in those with less severe deficiency. Vitamin D_sentence_118

Autoimmune diseases Vitamin D_section_14

Although tentative data link low levels of vitamin D to asthma, evidence to support a beneficial effect on asthmatics from supplementation is inconclusive. Vitamin D_sentence_119

One review found that vitamin D supplementation could reduce the need for steroids used to inhibit episode frequency in people with mild to moderate asthma, and that supplementation had no effect on day-to-day asthma symptoms. Vitamin D_sentence_120

In general practice, supplementation with vitamin D is not recommended for treatment or prevention of asthma. Vitamin D_sentence_121

Inflammatory bowel disease Vitamin D_section_15

Low levels of vitamin D are associated with two major forms of human inflammatory bowel disease (IBD): Crohn's disease and ulcerative colitis. Vitamin D_sentence_122

A meta-analysis of vitamin D therapy in IBD patients with vitamin D deficiency has shown that supplementation is effective at correcting vitamin D levels and is associated with improvements in scores for clinical disease activity and biochemical markers. Vitamin D_sentence_123

Other conditions Vitamin D_section_16

Diabetes – A systematic review of 2014 concluded that the available studies show no evidence of vitamin D3 supplementation having an effect on glucose homeostasis or diabetes prevention. Vitamin D_sentence_124

A review article of 2016 reported that while there is increasing evidence that vitamin D deficiency may be a risk factor for diabetes, over-all evidence regarding vitamin D levels and diabetes mellitus is contradictory, requiring further studies. Vitamin D_sentence_125

Depression – 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 depressive disorder had a moderate effect. Vitamin D_sentence_126

Cognition and dementia – A systematic review of clinical studies found an association between low vitamin D levels with cognitive impairment and a higher risk of developing Alzheimer's disease. Vitamin D_sentence_127

However, lower vitamin D concentrations are also associated with poor nutrition and spending less time outdoors. Vitamin D_sentence_128

Therefore, alternative explanations for the increase in cognitive impairment exist and hence a direct causal relationship between vitamin D levels and cognition could not be established. Vitamin D_sentence_129

Pregnancy – Low levels of vitamin D in pregnancy are associated with gestational diabetes, pre-eclampsia, and small (for gestational age) infants. Vitamin D_sentence_130

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. Vitamin D_sentence_131

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_sentence_132

Vitamin D supplementation is also likely to reduce the risk of gestational diabetes, undersized babies and of their poor rate of growth. Vitamin D_sentence_133

Pregnant women often do not take the recommended amount of vitamin D. Vitamin D_sentence_134

Weight loss – Though hypothesized that vitamin D supplementation may be an effective treatment for obesity apart from calorie restriction, one systematic review found no association of supplementation with body weight or fat mass. Vitamin D_sentence_135

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. Vitamin D_sentence_136

Allowable health claims Vitamin D_section_17

Governmental regulatory agencies stipulate for the food and dietary supplement industries certain health claims as allowable as statements on packaging. Vitamin D_sentence_137

European Food Safety Authority Vitamin D_sentence_138

Vitamin D_unordered_list_0

  • normal function of the immune systemVitamin D_item_0_0
  • normal inflammatory responseVitamin D_item_0_1
  • normal muscle functionVitamin D_item_0_2
  • reduced risk of falling in people over age 60Vitamin D_item_0_3

US Food and Drug Administration (FDA) Vitamin D_sentence_139

Vitamin D_unordered_list_1

  • "Adequate calcium and vitamin D, as part of a well balanced diet, along with physical activity, may reduce the risk of osteoporosis."Vitamin D_item_1_4

Health Canada Vitamin D_sentence_140

Vitamin D_unordered_list_2

  • "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."Vitamin D_item_2_5

Other possible agencies with claim guidance: Japan FOSHU and Australia-New Zealand. Vitamin D_sentence_141

Dietary intake Vitamin D_section_18

Recommended levels Vitamin D_section_19

Various institutions have proposed different recommendations for the amount of daily intake 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 µg (microgram) = 40 IU (international unit). Vitamin D_sentence_142

Vitamin D_table_general_2

United KingdomVitamin D_cell_2_0_0
Age groupVitamin D_header_cell_2_1_0 Intake (μg/day)Vitamin D_header_cell_2_1_1 Maximum intake (μg/day)Vitamin D_header_cell_2_1_2
Breast-fed infants 0–12 monthsVitamin D_cell_2_2_0 8.5 - 10Vitamin D_cell_2_2_1 25Vitamin D_cell_2_2_2
Formula-fed infants (<500 ml/d)Vitamin D_cell_2_3_0 10Vitamin D_cell_2_3_1 25Vitamin D_cell_2_3_2
Children 1 - 10 yearsVitamin D_cell_2_4_0 10Vitamin D_cell_2_4_1 50Vitamin D_cell_2_4_2
Children >10 and adultsVitamin D_cell_2_5_0 10Vitamin D_cell_2_5_1 100Vitamin D_cell_2_5_2
United StatesVitamin D_cell_2_6_0
Age groupVitamin D_header_cell_2_7_0 RDA (IU/day)Vitamin D_header_cell_2_7_1 (μg/day)Vitamin D_header_cell_2_7_2
Infants 0–6 monthsVitamin D_cell_2_8_0 400*Vitamin D_cell_2_8_1 10Vitamin D_cell_2_8_2
Infants 6–12 monthsVitamin D_cell_2_9_0 400*Vitamin D_cell_2_9_1 10Vitamin D_cell_2_9_2
1–70 yearsVitamin D_cell_2_10_0 600Vitamin D_cell_2_10_1 15Vitamin D_cell_2_10_2
71+ yearsVitamin D_cell_2_11_0 800Vitamin D_cell_2_11_1 20Vitamin D_cell_2_11_2
Pregnant/LactatingVitamin D_cell_2_12_0 600Vitamin D_cell_2_12_1 15Vitamin D_cell_2_12_2
Age groupVitamin D_header_cell_2_13_0 Tolerable upper intake level (IU/day)Vitamin D_header_cell_2_13_1 (µg/day)Vitamin D_header_cell_2_13_2
Infants 0–6 monthsVitamin D_cell_2_14_0 1,000Vitamin D_cell_2_14_1 25Vitamin D_cell_2_14_2
Infants 6–12 monthsVitamin D_cell_2_15_0 1,500Vitamin D_cell_2_15_1 37.5Vitamin D_cell_2_15_2
1–3 yearsVitamin D_cell_2_16_0 2,500Vitamin D_cell_2_16_1 62.5Vitamin D_cell_2_16_2
4–8 yearsVitamin D_cell_2_17_0 3,000Vitamin D_cell_2_17_1 75Vitamin D_cell_2_17_2
9+ yearsVitamin D_cell_2_18_0 4,000Vitamin D_cell_2_18_1 100Vitamin D_cell_2_18_2
Pregnant/lactatingVitamin D_cell_2_19_0 4,000Vitamin D_cell_2_19_1 100Vitamin D_cell_2_19_2
CanadaVitamin D_cell_2_20_0
Age groupVitamin D_header_cell_2_21_0 RDA (IU)Vitamin D_header_cell_2_21_1 Tolerable upper intake (IU)Vitamin D_header_cell_2_21_2
Infants 0–6 monthsVitamin D_cell_2_22_0 400*Vitamin D_cell_2_22_1 1,000Vitamin D_cell_2_22_2
Infants 7–12 monthsVitamin D_cell_2_23_0 400*Vitamin D_cell_2_23_1 1,500Vitamin D_cell_2_23_2
Children 1–3 yearsVitamin D_cell_2_24_0 600Vitamin D_cell_2_24_1 2,500Vitamin D_cell_2_24_2
Children 4–8 yearsVitamin D_cell_2_25_0 600Vitamin D_cell_2_25_1 3,000Vitamin D_cell_2_25_2
Children and Adults 9–70 yearsVitamin D_cell_2_26_0 600Vitamin D_cell_2_26_1 4,000Vitamin D_cell_2_26_2
Adults > 70 yearsVitamin D_cell_2_27_0 800Vitamin D_cell_2_27_1 4,000Vitamin D_cell_2_27_2
Pregnancy & LactationVitamin D_cell_2_28_0 600Vitamin D_cell_2_28_1 4,000Vitamin D_cell_2_28_2
Australia and New ZealandVitamin D_cell_2_29_0
Age groupVitamin D_header_cell_2_30_0 Adequate Intake (μg)Vitamin D_header_cell_2_30_1 Upper Level of Intake (μg)Vitamin D_header_cell_2_30_2
Infants 0–12 monthsVitamin D_cell_2_31_0 5*Vitamin D_cell_2_31_1 25Vitamin D_cell_2_31_2
Children 1–18 yearsVitamin D_cell_2_32_0 5*Vitamin D_cell_2_32_1 80Vitamin D_cell_2_32_2
Adults 19–50 yearsVitamin D_cell_2_33_0 5*Vitamin D_cell_2_33_1 80Vitamin D_cell_2_33_2
Adults 51–70 yearsVitamin D_cell_2_34_0 10*Vitamin D_cell_2_34_1 80Vitamin D_cell_2_34_2
Adults > 70 yearsVitamin D_cell_2_35_0 15*Vitamin D_cell_2_35_1 80Vitamin D_cell_2_35_2
European Food Safety AuthorityVitamin D_cell_2_36_0
Age groupVitamin D_header_cell_2_37_0 Adequate Intake (μg)Vitamin D_header_cell_2_37_1 Tolerable upper limit (μg)Vitamin D_header_cell_2_37_2
Infants 0–12 monthsVitamin D_cell_2_38_0 10Vitamin D_cell_2_38_1 25Vitamin D_cell_2_38_2
Children 1–10 yearsVitamin D_cell_2_39_0 15Vitamin D_cell_2_39_1 50Vitamin D_cell_2_39_2
Children 11–17 yearsVitamin D_cell_2_40_0 15Vitamin D_cell_2_40_1 100Vitamin D_cell_2_40_2
AdultsVitamin D_cell_2_41_0 15Vitamin D_cell_2_41_1 100Vitamin D_cell_2_41_2
Pregnancy & LactationVitamin D_cell_2_42_0 15Vitamin D_cell_2_42_1 100Vitamin D_cell_2_42_2
* Adequate intake, no RDA/RDI yet establishedVitamin D_cell_2_43_0

United Kingdom Vitamin D_section_20

The UK National Health Service (NHS) recommends that people at risk of vitamin D deficiency, breast-fed babies, formula-fed babies taking less than 500ml/day, and children aged 6 months to 4 years, should take daily vitamin D supplements throughout the year to ensure sufficient intake. Vitamin D_sentence_143

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 that cover up most of the skin, or with dark skin, such as having an African, African-Caribbean or south Asian background. Vitamin D_sentence_144

Other people may be able to make adequate vitamin D from sunlight exposure from April to September. Vitamin D_sentence_145

The NHS and Public Health England recommend that everyone, including pregnant and breastfeeding women, consider taking a daily supplement containing 10 µg (400 IU) of vitamin D during autumn and winter because of inadequate sunlight for vitamin D synthesis. Vitamin D_sentence_146

United States Vitamin D_section_21

The dietary reference intake for vitamin D issued in 2010 by the Institute of Medicine (IoM) (renamed National Academy of Medicine in 2015), superseded previous recommendations which were expressed in terms of Adequate Intake. Vitamin D_sentence_147

The recommendations were formed assuming the individual has no skin synthesis of vitamin D because of inadequate sun exposure. Vitamin D_sentence_148

The reference intake for vitamin D refers to total intake from food, beverages and supplements, and assumes that calcium requirements are being met. Vitamin D_sentence_149

The tolerable upper intake level (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." Vitamin D_sentence_150

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. Vitamin D_sentence_151

For U.S food and dietary supplement labeling purposes, the amount in a serving is expressed as a percent of Daily Value (%DV). Vitamin D_sentence_152

For vitamin D labeling purposes, 100% of the Daily Value was 400 IU (10 μg), but on May 27, 2016, it was revised to 800 IU (20 μg) to bring it into agreement with the RDA. Vitamin D_sentence_153

Compliance with the updated labeling regulations was required by January 1, 2020, for manufacturers with $10 million or more in annual food sales, and by January 1, 2021 for manufacturers with less than $10 million in annual food sales. Vitamin D_sentence_154

During the first six months following the January 1, 2020 compliance date, the FDA plans to work cooperatively with manufacturers to meet the new Nutrition Facts label requirements and will not focus on enforcement actions regarding these requirements during that time. Vitamin D_sentence_155

A table of the old and new adult Daily Values is provided at Reference Daily Intake. Vitamin D_sentence_156

Canada Vitamin D_section_22

Health Canada published recommended dietary allowances (RDA) and tolerable upper intake levels for vitamin D in 2012 based on the Institute of Medicine report. Vitamin D_sentence_157

Australia and New Zealand Vitamin D_section_23

Australia and New Zealand published nutrient reference values including guidelines for dietary vitamin D intake in 2005. Vitamin D_sentence_158

About a third of Australians have vitamin D deficiency. Vitamin D_sentence_159

European Union Vitamin D_section_24

The European Food Safety Authority (EFSA) in 2016 reviewed the current evidence, finding the relationship between serum 25(OH)D concentration and musculoskeletal health outcomes is widely variable. Vitamin D_sentence_160

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 nmol/L was a suitable target value. Vitamin D_sentence_161

For all people over the age of 1, including women who are pregnant or lactating, they set an adequate intake of 15 μg/day (600 IU). Vitamin D_sentence_162

The EFSA reviewed safe levels of intake in 2012, setting the tolerable upper limit for adults at 100 μg/day (4000 IU), a similar conclusion as the IOM. Vitamin D_sentence_163

The Swedish National Food Agency recommends a daily intake of 10 μg (400 IU) of vitamin D3 for children and adults up to 75 years, and 20 μg (800 IU) for adults 75 and older. Vitamin D_sentence_164

Non-government organisations in Europe have made their own recommendations. Vitamin D_sentence_165

The German Society for Nutrition recommends 20 µg. Vitamin D_sentence_166

The European Menopause and Andropause Society recommends postmenopausal women consume 15 µg (600 IU) until age 70, and 20 µg (800 IU) from age 71. Vitamin D_sentence_167

This dose should be increased to 100 µg (4,000 IU) in some patients with very low vitamin D status or in case of co-morbid conditions. Vitamin D_sentence_168

Credits to the contents of this page go to the authors of the corresponding Wikipedia page: D.