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64-402: Ergocalciferol , also known as vitamin D 2 and nonspecifically calciferol , is a type of vitamin D found in food and used as a dietary supplement . As a supplement it is used to prevent and treat vitamin D deficiency . This includes vitamin D deficiency due to poor absorption by the intestines or liver disease . It may also be used for low blood calcium due to hypoparathyroidism . It

128-425: 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

192-666: A direct causal relationship between vitamin D levels and cognition could not be established. People diagnosed with schizophrenia tend to have lower serum vitamin D concentration compared to those without the condition. This may be a consequence of the disease rather than a cause, due, for example, to low dietary vitamin D and less time spent exposed to sunlight. Results from supplementation trials have been inconclusive. Low levels of vitamin D in pregnancy are associated with gestational diabetes , pre-eclampsia , and small (for gestational age) infants. Although taking vitamin D supplements during pregnancy raises blood levels of vitamin D in

256-485: A higher risk of cancer in epidemiologic studies, the general conclusion is that there is insufficient evidence for an effect of vitamin D supplementation on the risk of cancer. Potential associations have been found between low vitamin D levels and the risk of developing several types of cancer. Meta-analyses of observational studies have found reduced risk of cancer incidence related to vitamin D intake and 25(OH)D levels, particularly for colorectal cancer , although

320-441: A long-term effect of calcium and/or vitamin D insufficiency, the latter contributing by reducing calcium absorption. In the absence of confirmed vitamin D deficiency there is no evidence that vitamin D supplementation without concomitant calcium slows or stops the progression of osteomalacia to osteoporosis. For older people with osteoporosis, taking vitamin D with calcium may help prevent hip fractures, but it also slightly increases

384-481: A lower intensive care unit (ICU) admission rate compared to those without supplementation, but without a change in mortality, but another review considered the evidence for treatment of COVID-19 to be very uncertain. 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. Vitamin D supplementation substantially reduced

448-400: A moderate effect. 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 . 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

512-409: A true vitamin . Instead it functions as a hormone ; the activation of the vitamin D pro-hormone produces calcitriol , the active form. Calcitriol then exerts its effects via the vitamin D receptor , a nuclear receptor found in various tissues throughout the body. Cholecalciferol is converted in the liver to calcifediol (also known as calcidiol or 25-hydroxycholecalciferol), while ergocalciferol

576-450: A vitamin D 2 supplement; both effectively improves vitamin D status. Vitamin D 2 from UV-irradiated yeast baked into bread or mushrooms is bioavailable and increases blood levels of 25(OH)D. Viosterol, the name given to early preparations of irradiated ergosterol , is essentially synonymous with ergocalciferol. However, currently, Viosterol is also the brand name for cholecalciferol (vitamin D 3 ) in some countries. Ergocalciferol

640-592: 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. Vitamin D deficiency and insufficiency have been associated with adverse outcomes in COVID-19. A review of supplement trials indicated

704-456: Is 20 to 50 nanograms per milliliter (ng/mL). Blood levels necessary to cause adverse effects in adults are thought to be greater than about 150 ng/mL. An excess of vitamin D causes abnormally hypercalcaemia (high blood concentrations of calcium), which can cause overcalcification of the bones and of soft tissues including arteries, heart and kidneys. Untreated, can lead to irreversible kidney failure. Symptoms of vitamin D toxicity may include

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768-502: Is a biological precursor of vitamin D 2 , the chemical name of which is ergocalciferol . Exposure of white button mushrooms to UV-C irradiation produces time-dependent increases in vitamin D2 concentrations in the mushrooms. Fungi are grown industrially to enable ergosterol extraction and preparation as a powder for sale as a vitamin D 2 dietary supplement and food additive . Preparations of irradiated ergosterol containing

832-406: Is a secosteroid formed by a photochemical bond breaking of a steroid , specifically, by the action of ultraviolet light (UV-B or UV-C) on ergosterol , a form of provitamin D 2 . Like cholecalciferol , ergocalciferol is inactive by itself. It requires two hydroxylations to become active: the first in the liver by CYP2R1 to form 25-hydroxyergocalciferol (ercalcidiol or 25-OH D 2 ), and

896-560: Is a sterol found in fungi, and named after ergot , the common name of members of the fungal genus Claviceps from which ergosterol was first isolated. Ergosterol is a component of yeast and other fungal cell membranes , serving many of the same functions that cholesterol serves in animal cells. Its specificity in higher fungi is thought to be related to the climatic instabilities (highly varying humidity and moisture conditions) encountered by these organisms in their typical ecological niches (plant and animal surfaces, soil). Thus, despite

960-497: Is a useful target for antifungal drugs. Ergosterol is also present in the cell membranes of some protists, such as trypanosomes . This is the basis for the use of some antifungals against West African sleeping sickness . Amphotericin B , an antifungal drug, targets ergosterol. It binds physically to ergosterol within the membrane, thus creating a polar pore in fungal membranes. This causes ions (predominantly potassium and hydrons ) and other molecules to leak out, which will kill

1024-484: Is accord on the adult maximum of 100 μg/d (4000 IU/d). In contrast, some non-government authors have proposed a safe upper intake level of 250 μg (10,000 IU) per day in healthy adults. In part, this is based on the observation that endogenous skin production with full body exposure to sunlight or use of tanning beds is comparable to taking an oral dose between 250 μg and 625 μg (10,000 IU and 25,000 IU) per day and maintaining blood concentrations on

1088-585: Is caused by a mutation of the CYP24A1 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 hypercalcaemia. The disorder can continue into adulthood. Supplementation with vitamin D is a reliable method for preventing or treating rickets . 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

1152-412: 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 calcitriol (1,25-dihydroxycholecalciferol), the biologically active form of vitamin D. Calcitriol circulates in

1216-409: Is defined as a blood 25-hydroxyvitamin D or 25(OH)D level below 12 ng/mL (30 nmol/liter). Vitamin D insufficiency is characterized by a blood 25(OH)D level 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

1280-669: Is found compared to those grown in the wild or dried in the sun. When fresh mushrooms or dried powders are purposely exposed to ultraviolet light, vitamin D 2 levels can be concentrated to much higher levels. The irradiation procedure does not cause significant discoloration, or whitening, of mushrooms. Claims have been made that a normal serving (approx. 2 oz or 60 grams) of fresh mushrooms treated with ultraviolet light have increased vitamin D content to levels up to 80 micrograms or 3200 IU if exposed to just five minutes of UV light after being harvested. Button mushrooms with enhanced vitamin D 2 content produced this way functions similarly to

1344-441: 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. (made from 7-dehydrocholesterol in

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1408-611: Is manufactured and sold under various brand names, including Deltalin ( Eli Lilly and Company ), Drisdol (Sanofi-Synthelabo), and Calcidol (Patrin Pharma). Vitamin D Vitamin D is a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium , magnesium , and phosphate , along with numerous other biological functions. In humans, the most significant compounds within this group are vitamin D 3 ( cholecalciferol ) and vitamin D 2 ( ergocalciferol ). The primary natural source of vitamin D

1472-400: Is not associated with a reduced risk of stroke, cerebrovascular disease , myocardial infarction , or ischemic heart disease . Supplementation does not lower blood pressure in the general population. One meta-analysis found a small increase in risk of stroke when calcium and vitamin D supplements were taken together. In general, vitamin D functions to activate the innate and dampen

1536-512: Is on the World Health Organization's List of Essential Medicines . Ergocalciferol may be used as a vitamin D supplement , whereas cholecalciferol (vitamin D 3 ) is produced naturally by the skin when exposed to ultraviolet light. Ergocalciferol (D 2 ) and cholecalciferol (D 3 ) are considered to be equivalent for vitamin D production, as both forms appear to have similar efficacy in ameliorating rickets and reducing

1600-502: Is synthesized by combining two molecules of farnesyl pyrophosphate, a 15-carbon-long terpenoid, into lanosterol, which has 30 carbons. Then, two methyl groups are removed, making ergosterol. The "azole" class of antifungal agents inhibit the enzyme that performs these demethylation steps in the biosynthetic pathway between lanosterol and ergosterol. Some protozoa, including Trichomonas and Leishmania are inhibited by drugs that target ergosterol synthesis and function Ergosterol

1664-417: Is taken by mouth or via injection into a muscle . Excessive doses can result in vitamin D toxicity causing increased urine production, high blood pressure , kidney stones , kidney failure , muscle weakness, and constipation. If high doses are taken for a long period of time, tissue calcification may occur. Normal doses are safe in pregnancy . It works by increasing the amount of calcium absorbed by

1728-505: Is that fatty tissue sequesters vitamin D. There is evidence that pathogenesis of uterine fibroids is associated with low serum vitamin D and that supplementation reduces size of fibroids. Governmental regulatory agencies stipulate for the food and dietary supplement industries certain health claims as allowable as statements on packaging. Europe: European Food Safety Authority (EFSA) US: Food and Drug Administration (FDA) Ergosterol Ergosterol (ergosta-5,7,22-trien-3β-ol)

1792-444: Is the synthesis of cholecalciferol in the lower layers of the skin’s epidermis , triggered by a photochemical reaction with ultraviolet B (UV-B) radiation from sunlight or UV-B lamps . Cholecalciferol and ergocalciferol can also be obtained through diet and supplements . 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

1856-485: Is the toxic state of an excess of vitamin D. There is not general agreement about the intake levels at which vitamin D may cause harm. From a review of the human trial literature, "Doses below 10,000 IU/day are not usually associated with toxicity, whereas doses equal to or above 50,000 IU/day for several weeks or months are frequently associated with toxic side effects including documented hypercalcemia." The normal range for blood concentration of 25-hydroxyvitamin D in adults

1920-482: The adaptive immune systems with antibacterial, antiviral and anti-inflammatory effects. Low serum levels of vitamin D appear to be a risk factor for tuberculosis . However, supplementation trials showed no benefit. Vitamin D supplementation at low doses may slightly decrease the overall risk of acute respiratory tract infections . The benefits were found in children and adolescents, and were not confirmed with higher doses. Vitamin D deficiency has been linked to

1984-454: The side chain : vitamin D 2 has a double bond between carbons 22 and 23, and a methyl group on carbon 24. Numerous vitamin D analogues have also been synthesized. The active vitamin D metabolite, calcitriol, exerts its biological effects by binding to the vitamin D receptor (VDR), which is primarily located in the nuclei of target cells. When calcitriol binds to the VDR, it enables

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2048-455: 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 panel maintain that they used a "standard procedure for dietary recommendations" and that the report is solidly based on the data. Vitamin D 3 supplementation has been tentatively found to lead to a reduced risk of death in

2112-464: 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 2 . 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 safe levels of sunlight exposure , particularly due to

2176-457: The added energy requirements of ergosterol synthesis (if compared to cholesterol), ergosterol is thought to have evolved as a nearly ubiquitous, evolutionarily advantageous fungal alternative to cholesterol. This advantage could be linked to the presence of two conjugated double bonds in the structure (B-ring) of ergosterol giving it antioxidant properties. Because ergosterol is present in cell membranes of fungi, yet absent in those of animals, it

2240-399: The associated risk of skin cancer . Vitamin D obtained from the diet or synthesised in the skin is biologically inactive. It becomes active by two enzymatic hydroxylation steps, the first occurring in the liver and the second in the kidneys . Since most mammals can synthesise sufficient vitamin D with adequate sunlight exposure, it is technically not essential in the diet and thus not

2304-579: The blood as a hormone, playing a major role in regulating calcium and phosphate concentrations, as well as promoting bone health and bone remodeling . Vitamin D has a significant role in calcium homeostasis and metabolism. Its discovery was due to effort to identify the dietary deficiency in children with rickets , the childhood form of osteomalacia . 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

2368-433: The cell. Amphotericin B has been replaced by safer agents in most circumstances, but is still used, despite its side effects, for life-threatening fungal or protozoan infections. Fluconazole , miconazole , itraconazole , clotrimazole , and myclobutanil work in a different way, inhibiting synthesis of ergosterol from lanosterol by interfering with 14α-demethylase . Ergosterol is a smaller molecule than lanosterol; it

2432-541: The developed world, can cause a softening and weakening of growing bones, leading to a condition known as rickets . Vitamin D deficiency is prevalent globally, particularly among the elderly, and remains common in both children and adults. This deficiency impairs bone mineralization and causes bone damage, leading to bone-softening diseases such as rickets in children and osteomalacia in adults. Low blood calcifediol (25-hydroxyvitamin D 3 ) levels can result from limited sun exposure. When vitamin D levels are deficient,

2496-417: The elderly, but the effect has not been deemed pronounced, or certain enough, to make taking supplements recommendable. Other forms (vitamin D 2 , 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

2560-486: The following: increased thirst , increased urination , nausea, vomiting, diarrhea, decreased appetite, irritability, constipation, fatigue, muscle weakness and insomnia. In almost every case, stopping the vitamin D supplementation combined with a low-calcium diet and corticosteroid drugs will allow for a full recovery within a month. In 2011, the U.S. National Academy of Medicine revised tolerable upper intake levels (UL) to protect against vitamin D toxicity. Prior to

2624-582: The immune system, with VDRs being expressed in several white blood cells, including monocytes and activated T and B cells . In vitro studies indicate that vitamin D increases the expression of the tyrosine hydroxylase gene in adrenal medullary cells and affects the synthesis of neurotrophic factors , nitric oxide synthase , and glutathione , which may control the body's response and adaption to stress . VDR expression decreases with age. A diet insufficient in vitamin D, combined with inadequate sunlight exposure, can lead to vitamin D deficiency, which

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2688-421: The incidence of falls in elderly patients. Conflicting reports exist, however, concerning the relative effectiveness, with some studies suggesting that ergocalciferol has less efficacy based on limitations in absorption, binding, and inactivation. A meta-analysis concluded that evidence usually favors cholecalciferol in raising vitamin D levels in blood, although it stated more research is needed. Ergocalciferol

2752-544: The intestine, bone, kidney, and parathyroid gland cells plays a crucial role in maintaining calcium and phosphorus levels in the blood, a process that is assisted by parathyroid hormone and calcitonin , thereby supporting bone health . One of the most important functions of vitamin D is to maintain skeletal calcium balance by promoting calcium absorption in the intestines, promoting bone resorption by increasing osteoclast numbers, maintaining calcium and phosphate levels necessary for bone formation, and facilitating

2816-528: The intestines and reabsorbed by the kidneys. Food in which it is found include some mushrooms . Ergocalciferol was first described in 1936. Ergocalciferol is available as a generic medication and over the counter . In 2022, it was the 38th most commonly prescribed medication in the United States, with more than 15   million prescriptions. Certain foods such as breakfast cereal and margarine have ergocalciferol added to them in some countries. It

2880-631: 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. 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. Maternal vitamin D deficiency can cause fetal bone defects from before birth and impairment of bone quality after birth. Rickets typically appear between 3 and 18 months of age. This condition can be caused by vitamin D, calcium or phosphorus deficiency. Vitamin D deficiency remains

2944-501: The main cause of rickets among young infants in most countries because breast milk is low in vitamin D, and darker skin, social customs and climatic conditions can contribute to inadequate sun exposure. A post-weaning Western omnivore diet characterized by high intakes of meat, fish, eggs and vitamin D fortified milk is protective, whereas low intakes of those foods and high cereal/grain intake contributes to risk. For young children with rickets, supplementation with vitamin D plus calcium

3008-425: The mother at term, the full extent of benefits for the mother or baby is unclear. Pregnant women often do not take the recommended amount of vitamin D, however, the benefits and risk of vitamin D supplementation during pregnancy have not been well studied. Obesity increases the risk of having low serum vitamin D. Supplementation does not lead to weight loss, but weight loss increases serum vitamin D. The theory

3072-420: The order of 100 ng/mL. Although in the U.S. the adult UL is set at 4000 IU/day, over-the-counter products are available at 5000 and 10000 IU. The percentage of the U.S. population taking over 4000 IU/day has increased since 1999. People with primary hyperparathyroidism , are more sensitive to vitamin D supplementation, and as a consenquence may develop hypercalcemia. Idiopathic infantile hypercalcemia

3136-467: The proper function of parathyroid hormone to sustain serum calcium levels. Vitamin D deficiency can lead to decreased bone mineral density , increasing the risk of osteoporosis and bone fractures due to its impact on mineral metabolism. Consequently, vitamin D is also important for bone remodeling , acting as a potent stimulator of bone resorption. The VDR also regulates cell proliferation and differentiation . Additionally, vitamin D influences

3200-702: The rate of moderate or severe exacerbations of chronic obstructive pulmonary disease (COPD). Vitamin D supplementation does not help prevent asthma attacks or alleviate symptoms. A meta-analysis reported that vitamin D supplementation significantly reduced the risk of type 2 diabetes for non-obese people with prediabetes . Another meta-analysis reported that vitamin D supplementation significantly improved glycemic control [homeostatic model assessment-insulin resistance (HOMA-IR)], hemoglobin A1C (HbA1C), and fasting blood glucose (FBG) in individuals with type 2 diabetes. In prospective studies, high versus low level of vitamin D

3264-697: 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 myocardial infarction , stroke or cerebrovascular disease , cancer, bone fractures or knee osteoarthritis . A US 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 intake of either calcium or vitamin D, and were often conflicting." Some researchers claim

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3328-415: The receptor to act as a transcription factor , modulating the gene expression of transport proteins involved in calcium absorption in the intestine, such as TRPV6 and calbindin . The VDR is part of the nuclear receptor superfamily of steroid hormone receptors , which are hormone-dependent regulators of gene expression. These receptors are expressed in cells across most organs. Activation of VDR in

3392-607: The revision the UL for ages 9+ years was 50 μg/d (2000 IU/d). Per the revision: "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." The U.S. ULs in microgram (mcg or μg) and International Units (IU) for both males and females, by age, are: As shown in the Dietary intake section, different government organizations have set different ULs for age groups, but there

3456-659: The risk of stomach and kidney problems. The reduced rick for fractures is not seen in healthier, community-dwelling elderly. Low serum vitamin D levels have been associated with falls , but taking extra vitamin D does not appear to reduce that risk. Athletes who are vitamin D deficient are at an increased risk of stress fractures and/or major breaks, particularly those engaging in contact sports. Incremental decreases in risk are observed with rising serum 25(OH)D concentrations plateauing at 50   ng/mL with no additional benefits seen in levels beyond this point. While serum low 25-hydroxyvitamin D status has been associated with

3520-483: The second in the kidney by CYP27B1 , to form the active 1,25-dihydroxyergocalciferol (ercalcitriol or 1,25-(OH) 2 D 2 ), which activates the vitamin D receptor . Unlike cholecalciferol , 25-hydroxylation is not performed by CYP27A1 for ergocalciferol. Ergocalciferol and metabolites have lower affinity to the vitamin D-binding protein compared to the D 3 counterparts. The binding affinity of ercalcitriol to

3584-728: The severity of inflammatory bowel disease (IBD). However, whether vitamin D deficiency causes IBD or is a consequence of the disease is not clear. Supplementation leads to improvements in scores for clinical inflammatory bowel disease activity and biochemical markers and less frequent relapse of symptoms in IBD. As of September 2022 the US National Institutes of Health state there is insufficient evidence to recommend for or against using vitamin D supplementation to prevent or treat COVID-19. The UK National Institute for Health and Care Excellence (NICE) does not recommend to offer

3648-413: The skin). (made from 7-dehydrositosterol ) Several forms ( vitamers ) of vitamin D exist, with the two major forms being vitamin D 2 or ergocalciferol, and vitamin D 3 or cholecalciferol. The term 'vitamin D' refers to either D 2 or D 3 , or both, and is known collectively as calciferol. Vitamin D 2 was chemically characterized in 1931. In 1935, the chemical structure of vitamin D 3

3712-399: The strength of the associations was classified as weak. Vitamin D receptor and SNAI2 are found to be involved in the metastastic process of osteosarcoma . While randomized controlled trials 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. Vitamin D supplementation

3776-495: The total absorption of dietary calcium can decrease from the normal range of 60–80% to 15%. Dark-skinned individuals living in temperate climates are more likely to have low vitamin D levels. This is because melanin 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. Vitamin D toxicity, or hypervitaminosis D,

3840-550: The vitamin D receptor is similar to that of calcitriol . Ergocalciferol itself and metabolites can be deactivated by 24-hydroxylation. Fungus , from USDA nutrient database (per 100g), D 2 + D 3 : Lichen Plantae The vitamin D 2 content in mushrooms and C. arbuscula increase with exposure to ultraviolet light. Ergosterol (provitamin D 2 ) found in these fungi is converted to previtamin D 2 on UV exposure, which then turns into vitamin D 2 . As cultured mushrooms are generally grown in darkness, less vitamin D 2

3904-529: 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. 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

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3968-417: Was defined and shown to result from the ultraviolet irradiation of 7-dehydrocholesterol. Although a chemical nomenclature for vitamin D forms was recommended in 1981, alternative names remain commonly used. Chemically, the various forms of vitamin D are secosteroids , meaning that one of the bonds in the steroid rings is broken. The structural difference between vitamin D 2 and vitamin D 3 lies in

4032-596: Was respectively associated with significant decrease in risk of type 2 diabetes, combined type 2 diabetes and prediabetes, and prediabetes. A 2011 Cochrane systematic review examined one study that showed vitamin D together with insulin maintained levels of fasting C-peptide after 12 months better than insulin alone. However, it is important to highlight that the studies available to be included in this review presented considerable flaws in quality and design. A meta-analysis of observational studies showed that children with ADHD have lower vitamin D levels, and that there

4096-467: Was superior to the vitamin alone for bone healing. Characteristics of osteomalacia are softening of the bones, leading to bending of the spine, bone fragility, and increased risk for fractures. Osteomalacia is usually present when 25-hydroxyvitamin D levels are less than about 10   ng/mL. Osteomalacia progress to osteoporosis , a condition of reduced bone mineral density with increased bone fragility and risk of bone fractures. Osteoporosis can be

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