Vitamin D: benefits, dosage, contraindications
Other name(s)
calciferols, Alfacalcidol, Calcifediol, Calcipotriol, Calcitriol, Dihydrotachysterol
Scientific name(s)
Ergocalciferol (D2), Cholecalciferol (D3)
Family or group:
Vitamins
Active ingredients:
Vitamin D3
Indications
Scoring methodology
EFSA approval.
Vitamin D deficiency ✪✪✪✪✪
Vitamin D deficiency is common and underdiagnosed. The etiologies of hypovitaminosis D are multiple: decreased synthesis of cholecalciferol, low sun exposure, use of sunscreen creams, dark skin phototype, hepatic insufficiency, isoniazid treatment, genetic abnormality, renal insufficiency... The clinical manifestations of vitamin D deficiency are mainly musculoskeletal. Osteoporosis, osteomalacia in adults, and rickets in children are well-known bone manifestations. Unlike osteoporosis, osteomalacia is associated with generalized or localized bone pain (pain on pressure of the sternum or the tibial crest). A deficiency can also lead to proximal muscle weakness and may cause a waddling gait with lateral rocking movements (a "penguin gait"). In cases of insufficient intake, vitamin D is taken as weekly doses of 400 to 2000 IU (10 to 50 µg) for eight weeks. In confirmed nutritional rickets in children, in the absence of hypocalcemia, 25-OH vitamin D may be given at a dose of 1500 to 3000 IU per day for six to eight weeks, then 300 to 400 IU per day. In cases of hypocalcemia, the hypocalcemia should be treated for a few days before initiating vitamin D.
Posologie
Oral
400 - 2000 IU
8 - weeks
Adults
Bone health ✪✪✪✪✪
Vitamin D plays a major role in the regulation of blood calcium levels, blood phosphate levels, and bone homeostasis.rnrnEuropean health authorities (EFSA, European Food Safety Authority, and the European Commission) have concluded that dietary supplements containing vitamin D (calciferols) can claim to contribute to the intestinal absorption and utilization of calcium and phosphorus, to the maintenance of normal blood calcium levels, to normal bone growth in children, and to the maintenance of normal bone health.rnrn
Posologie
Orally
600 - 4000 IU
Adults
cholecalciferol
Hypoparathyroidism ✪✪✪✪✪
Oral administration of calcitriol is effective at increasing serum calcium concentrations in people with hypoparathyroidism or pseudohypoparathyroidism.rnrnIndeed, the relationship between vitamin D levels and those of parathyroid hormone (PTH) appears to be individually dependent on calcium intake. Dietary calcium influences PTH levels and, in turn, changes in PTH can alter the turnover of vitamin D metabolites. PTH acts indirectly by stimulating the 1-alpha-hydroxylation of vitamin D which, when activated to 1,25-dihydroxyvitamin D (1,25(OH)2D3), promotes intestinal calcium absorption.rnrnCalcium deficiency could therefore worsen vitamin D deficiency, whereas high intakes have, on the contrary, a vitamin D–sparing effect. rnrnIn cases of hypoparathyroidism, supplementation with vitamin D2 or vitamin D3 should be added when there is an associated deficiency or systematically at a dose of 400 to 800 IU/day.rnrn
Posologie
Orally
400 - 800 IU
Fractures ✪✪✪✪✪
The rate of bone fractures in older adults appears to be significantly reduced by vitamin D supplementation at 700 IU or more. Indeed, most studies use doses between 700 and 1000 IU, while lower doses do not seem to be effective.rnrnMoreover, concurrent calcium supplementation (and possibly vitamin K) appears to have a protective effect on bone.rnrn
Posologie
Oral
700 - 1000 IU
Seniors
Skeletal and Extraskeletal Actions of Vitamin D: Current Evidence and Outstanding Questions
Need for additional calcium to reduce the risk of hip fracture with vitamin d supplementation: evidence from a comparative metaanalysis of randomized controlled trials.
Patient level pooled analysis of 68 500 patients from seven major vitamin D fracture trials in US and Europe.
Osteoporosis ✪✪✪✪✪
In cross-sectional studies, low 25(OH)D levels are associated with decreased bone mineral density (BMD), after adjustment for age, body mass index and calcium intake.rnrnThe National Osteoporosis Foundation (NOF) recommended in 2014 a daily vitamin D intake of 800 to 1,000 IU along with calcium to prevent osteoporosis in adults over 50. In patients with osteoporosis, the NOF recommends using vitamin D supplementation to maintain adequate vitamin D levels.rnrnThese recommendations are supported by clinical research showing that oral intake of vitamin D3 (cholecalciferol) with calcium supplements can reduce postmenopausal bone loss, may help prevent osteoporosis, and decrease the risk of fractures.rnrn
Posologie
Oral
800 - 1000 IU
Seniors
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.
Meta-analyses of therapies for postmenopausal osteoporosis. VIII: Meta-analysis of the efficacy of vitamin D treatment in preventing osteoporosis in postmenopausal women.
Fracture prevention with vitamin D supplementation: a meta-analysis of randomized controlled trials.
Vitamin D analogs versus native vitamin D in preventing bone loss and osteoporosis-related fractures: a comparative meta-analysis.
News about vitamin D
Evidence-based guidelines for the treatment of postmenopausal osteoporosis: a consensus document of the Belgian Bone Club.
Psoriasis ✪✪✪✪✪
The topical application of vitamin D in the form of calcitriol or other vitamin D analogues appears effective for the treatment of plaque psoriasis in some patients, including the chronic form. Topical vitamin D or its analogues in combination with topical corticosteroids appears more effective than treatment with corticosteroids alone.
Posologie
Topically
calcitriol
Topical vitamin D analogues alone or in association with topical steroids for psoriasis: a systematic review.
A two-compound product containing calcipotriol and betamethasone dipropionate provides rapid, effective treatment of psoriasis vulgaris regardless of baseline disease severity.
Combination treatments for psoriasis: a systematic review and meta-analysis.
Topical treatments for chronic plaque psoriasis.
Mixed treatment comparison of a two-compound formulation (TCF) product containing calcipotriol and betamethasone dipropionate with other topical treatments in psoriasis vulgaris.
Pregnancy ✪✪✪✪✪
Vitamin D, often associated with bone health, also plays a crucial role in the management of autoimmune diseases and allergies, as well as in maternal and fetal health during pregnancy. Preliminary research has shown that vitamin D supplementation may attenuate the severity of allergy symptoms such as allergic rhinitis, particularly when vitamin D levels are restored to an adequate threshold. Studies also suggest that insufficient vitamin D levels are associated with an increased risk of exacerbations and a greater need for medication in patients with asthma. Although clinical research findings are mixed, some meta-analyses have indicated that vitamin D supplementation may reduce the rate of asthma exacerbations in adults and children. Furthermore, vitamin D has been evaluated for its impact on other health outcomes during pregnancy, including preeclampsia, gestational diabetes, and markers of insulin resistance, potentially offering benefits in preventing and improving glycemic and lipid indices. Regarding child development, although some research suggests that increased vitamin D levels during pregnancy are associated with better anthropometric and neurodevelopmental outcomes, other studies have not shown a significant effect of vitamin D supplementation on children's neurological development. In summary, vitamin D supplementation during pregnancy offers significant benefits for maternal and fetal health, as confirmed by a meta-analysis including 30 trials and 7,033 women. Although the quality of evidence varies, vitamin D supplementation alone appears to reduce the risks of preeclampsia, gestational diabetes, and low birth weight, and may decrease the risk of severe postpartum hemorrhage.
Posologie
Oral administration
600 IU
Synergies
Vitamin D supplementation for women during pregnancy
Maternal vitamin D status and risk of gestational diabetes mellitus: A systematic review and meta-analysis of prospective cohort studies
The effect of combined supplementation with vitamin D and omega-3 fatty acids on blood glucose and blood lipid levels in patients with gestational diabetes
Effects of vitamin D supplementation during pregnancy on offspring health at birth: A meta-analysis of randomized controlled trails
Vitamin D Supplementation and Allergic Diseases during Childhood: A Systematic Review and Meta-Analysis
Relationship between vitamin D and asthma from gestational to adulthood period: a meta-analysis of randomized clinical trials
Therapeutic effect of vitamin D supplementation on allergic rhinitis
Vitamin D supplementation during pregnancy and the risk of wheezing in offspring: a systematic review and dose-response meta-analysis
Asthma ✪✪✪✪✪
Analyses of clinical trials show that taking vitamin D for 3 months to 1 year reduces the number of asthma exacerbations by 31% to 36% in adults and children with asthma.rnrnVitamin D3 (cholecalciferol) was used at various dosages, either 100,000 IU followed by 4,000 IU per day for 7 months, or 120,000 IU every two months for 1 year.rnrn
Posologie
Oral administration
4,000 - 100,000 IU
7 - months
Vitamin D supplementation to prevent asthma exacerbations: a systematic review and meta-analysis of individual participant data.
Vitamin D supplementation in children may prevent asthma exacerbation triggered by acute respiratory infection.
Serum vitamin D levels and severe asthma exacerbations in the Childhood Asthma Management Program study.
Serum vitamin D levels and markers of severity of childhood asthma in Costa Rica.
Premenstrual syndrome ✪✪✪✪✪
Increasing vitamin D intake appears to reduce the risk of developing premenstrual syndrome (PMS) and the severity of symptoms. Indeed, a clinical study shows that taking vitamin D at a dose of 400 IU/day in combination with 1000 mg/day of calcium for 10 days can reduce the severity of PMS symptoms.
Posologie
Oral administration
400 IU
10 days
Women
Synergies
Type 2 diabetes ✪✪✪✪✪
Observational research has shown that low vitamin D levels are associated with a higher risk of prediabetes, and that a diet rich in vitamin D is linked to a lower risk of developing diabetes. Moreover, in patients with vitamin D deficiency and prediabetes, vitamin D may improve beta-cell function, suggesting a reduction in disease progression.rnrnClinical research in adults with vitamin D deficiency shows that taking 50,000 IU of vitamin D per week for 3 months, then once monthly for 3 months, slightly improves insulin resistance and beta-cell function, but does not affect fasting and postprandial blood glucose compared with placebo. rnrnOral vitamin D may improve glycemic indices in some patients with type 2 diabetes, but clinical trial results remain conflicting. rnrn
Posologie
Oral
5000 IU
Vitamin D and type 2 diabetes: a systematic review
Vitamin D supplementation and glycemic control in type 2 diabetes patients: A systematic review and meta-analysis
Does high-dose vitamin D supplementation impact insulin resistance and risk of development of diabetes in patients with pre-diabetes? A double-blind randomized clinical trial
Respiratory infections ✪✪✪✪✪
Increased vitamin D levels during pregnancy have been associated with a lower incidence of respiratory infections in children. However, two meta-analyses of small clinical trials show a limited effect of prenatal vitamin D supplementation on the incidence of respiratory infections in infants or children (a 19% reduction in the risk of wheezing compared with the control group). In children, most research shows that vitamin D supplementation reduces the risk of respiratory infections. A meta-analysis of clinical trials conducted in children aged 1 to 16 years shows that taking vitamin D reduces the risk of suffering a respiratory infection compared with the control group. Daily or weekly doses of vitamin D appear to be more beneficial than single doses. Observational studies in adults have shown that low vitamin D levels are associated with worsened complications related to respiratory infections, and even with increased mortality from respiratory infections in adults aged 50 to 75 years. However, meta-analyses of prospective clinical trials in adults show that taking vitamin D supplements of 300 to 4,000 IU per day for 7 weeks to 5 years does not reduce the likelihood of developing a respiratory infection or serious respiratory complications, such as emergency department visits, hospitalization, and death, compared with placebo. By contrast, the largest single clinical trial, conducted in adults aged at least 60 years, shows that taking vitamin D3 (cholecalciferol) at 60,000 IU once a month for up to 5 years reduces the duration of overall and severe respiratory symptoms but does not reduce the incidence of respiratory illness, compared with placebo.
Posologie
Oral
4000 IU
Infant Respiratory Tract Infections or Wheeze and Maternal Vitamin D in Pregnancy: A Systematic Review
Vitamin D supplementation during pregnancy: state of the evidence from a systematic review of randomized trials
Vitamin D Insufficiency and Deficiency and Mortality from Respiratory Diseases in a Cohort of Older Adults: Potential for Limiting the Death Toll during and beyond the COVID-19 Pandemic?
Prenatal vitamin D status and respiratory and allergic outcomes in childhood: A meta-analysis of observational studies
The effect of vitamin D supplementation on acute respiratory tract infection in older Australian adults: an analysis of data from the D-Health Trial
Vitamin D for prevention of respiratory tract infections: A systematic review and meta-analysis
Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data
Autoimmune diseases ✪✪✪✪✪
Vitamin D plays a crucial role in managing autoimmune diseases by influencing immune status through environmental, genetic, and epidemiological factors. Its insufficiency has been associated with an increased prevalence of autoimmune disorders, notably type 1 diabetes, multiple sclerosis, systemic lupus, and Crohn's disease. Studies in animal models and epidemiological observations suggest that vitamin D may reduce inflammation and improve T-cell function, offering protection against autoimmune diseases by regulating immune responses and decreasing inflammatory cytokines.
Posologie
Oral
400 - 2000 IU
Parkinson's disease ✪✪✪✪✪
A low serum level of vitamin D is correlated with an increased risk of Parkinson's disease and is furthermore associated with the severity of the pathological condition. rnrnIndeed, vitamin D can protect neurons from stressors, although a deficiency does not appear to inherently increase the risk of neuronal damage to cells associated with the disease.rnrnPreliminary research shows that taking 1200 IU/day of cholecalciferol (vitamin D3) for one year significantly slows disease progression in affected subjects.rnrn
Posologie
Orally
1200 IU
1 - years
Seniors
Cancer ✪✪✪✪✪
Epidemiological research has shown that a higher serum vitamin D level is associated with a decreased risk of mortality in patients with colorectal cancer. rnrnIndeed, in an analysis of studies assessing the association between serum vitamin D levels and colorectal cancer risk, people with serum vitamin D levels of 33 ng/mL or higher had a 50% lower risk of developing colorectal cancer compared with those with levels of 12 ng/mL or lower.rnrnHowever, it is unclear whether vitamin D supplementation improves survival in patients with colorectal cancer.rnrnSome research shows that a high calcium intake is associated with a reduced risk of adenoma recurrence and colorectal cancer among people whose vitamin D levels are above average.rnrnIn cases of colorectal cancer, vitamin D has been used at 8,000 IU per day during the first cycle of chemotherapy, then 4,000 IU per day for subsequent cycles.rnrnOn the other hand, some research has found that higher vitamin D intake is associated with a 17% reduction in breast cancer risk in pre- and perimenopausal women, but not in postmenopausal women.rnrn
Posologie
Oral
4,000 - 8,000 IU
Depression ✪✪✪✪✪
The role of vitamin D in the treatment of depression is unclear. Meta-analyses show that vitamin D supplementation does not improve depressive symptoms in general. However, some studies suggest that vitamin D may be beneficial in improving depressive symptoms in people with clinically significant symptoms and with an existing vitamin D deficiency prior to supplementation.rnrnVitamin D3 (cholecalciferol) has been administered as a single dose of 150,000 to 300,000 IU, or at daily and weekly doses ranging between 400 and 5,000 IU per day or 20,000 to 40,000 IU per week for 6 weeks to 2 years.rnrn
Posologie
Oral
400 - 5000 IU
2 - years
Multiple sclerosis ✪✪✪✪✪
The demographic study showed that long-term vitamin D supplementation in women reduces the risk of multiple sclerosis (MS) by up to 40%. The effect appears to be dose-dependent. Intake of at least 400 IU per day, mainly in the form of a multivitamin supplement, appears to have the greatest protective effect. Further research has found that higher levels of calcifediol (25-hydroxyvitamin D) are associated with a significantly lower risk of developing MS.rnrnVitamin D supplementation does not appear to have an effect on MS relapses. Indeed, meta-analyses show that vitamin D supplementation, whether low- or high-dose, does not affect MS relapse rate or the number of nerve lesions.rnrn
Posologie
Oral
400 IU
Systemic lupus erythematosus ✪✪✪✪✪
Clinical studies have shown that taking vitamin D3 (cholecalciferol) at a dose of 2000 IU per day or 50,000 IU per week appears to reduce anti-native DNA antibodies, a marker of disease activity, compared with placebo in patients with systemic lupus erythematosus.
Posologie
Orally
2000 IU
COVID-19 ✪✪✪✪✪
The evidence for the role of vitamin D in preventing COVID-19 is conflicting. Although some observational research suggests that low vitamin D levels are associated with an increased risk of COVID-19, a large meta-analysis of observational studies found that vitamin D deficiency in adults was not associated with an increased risk of COVID-19 infection. However, 65% more people with severe disease had a vitamin D deficiency. In addition, vitamin D insufficiency, defined by blood levels below 30 ng/mL, was associated with more than an 80% increase in the risk of hospitalization or death from COVID-19. However, many of these studies did not account for patient age or other comorbidities. Some research has also examined an association between the use of vitamin D supplements and COVID-19 infection rates or disease severity. In the UK population, an observational study found that regular use of vitamin D supplements between 2006 and 2010 was associated with a 34% lower risk of COVID-19 infection. This result remained positive after adjusting for baseline health status and the use of other micronutrients. However, a high-quality prospective clinical trial conducted in patients hospitalized for moderate to severe COVID-19 shows that taking a single oral dose of 200,000 IU of vitamin D3 does not reduce length of hospital stay compared with placebo. In addition, it had no effect on in-hospital mortality, ICU admission, or the need for ventilation. The majority of patients in this study were vitamin D sufficient.
Posologie
Orally
400 - 1000 IU
Vitamin D Status Is Associated With In-Hospital Mortality and Mechanical Ventilation: A Cohort of COVID-19 Hospitalized Patients
Vitamin D supplementation, COVID-19 and disease severity: a meta-analysis
Vitamin D deficiency aggravates COVID-19: systematic review and meta-analysis
Vitamin D Insufficiency and Deficiency and Mortality from Respiratory Diseases in a Cohort of Older Adults: Potential for Limiting the Death Toll during and beyond the COVID-19 Pandemic?
Vitamin D concentrations and COVID-19 infection in UK Biobank
Habitual use of vitamin D supplements and risk of coronavirus disease 2019 (COVID-19) infection: a prospective study in UK Biobank
Association of Vitamin D Levels, Race/Ethnicity, and Clinical Characteristics With COVID-19 Test Results
Properties
Essential
Vitamin D plays a major role in the regulation of blood calcium, blood phosphate, and bone homeostasis.rnrnThe active vitamin D metabolite, 1,25(OH)2D, has both genomic and non-genomic effects.rnrnThe genomic effects are well known and involve a specific receptor, the vitamin D receptor (VDR), which is expressed in most cell types and therefore in virtually all tissues, meaning that nearly all cells are potential targets of calcitriol. This translates into vitamin D effects on the regulation of genes involved in metabolic pathways as diverse as calcium metabolism, proliferation, cellular differentiation, inflammation, apoptosis, and angiogenesis...rnrnVitamin D and its metabolites are also responsible for non-genomic effects. These effects of calcitriol depend on a membrane receptor, protein disulfide isomerase family A member 3 (Pdia3). The role of this receptor has been well described in the enterocyte (a type of cell of the intestinal epithelium), where it contributes to the rapid uptake of calcium. rnrnEuropean health authorities have determined that products containing vitamin D can claim to contribute to intestinal absorption and utilization of calcium and phosphorus, the maintenance of normal blood calcium levels, normal bone growth in children, the maintenance of normal bones, muscles, teeth and the immune system, cell division and the normal functioning of the immune system in children aged 3 to 18 years.rnrn
Usages associés
Bone density
Any calcium therapy or consumption of products containing calcium should be associated with vitamin D which, in its di-hydroxylated form, is involved in the active transport mechanism of the mineral across the enterocyte wall. Recent studies indicate that 25(OH)D could directly modulate bone cells that possess not only specific receptors (VDR), but also the 1α-hydroxylase necessary for converting the molecule into its active metabolite. With regard to demonstrating the bone effects of vitamin D, it is clear that the secondary hyperparathyroidism that develops during vitamin D deficiency is extremely deleterious since it leads to an acceleration of resorption. For this reason, in a state of deficiency, supplementation can improve remodeling, mass, and bone consolidation.
Usages associés
Anticancer
In addition to bone mineralization and the maintenance of calcium balance, 1,25-dihydroxyvitamin D has physiological functions, including the regulation of growth and differentiation of a large portion of normal and malignant cells. It is known that cancer cells possess vitamin D receptors which, in turn, act on more than 200 genes, some of which are involved in cancer development. Vitamin D acts on cancer cells by decreasing their proliferation, reducing the risk of growth (by decreasing their vascularization), inhibiting the transformation of precancerous cells into cancerous cells and, finally, inducing apoptosis in some affected cells.
Usages associés
Cardiovascular
Cardiomyocytes, vascular smooth muscle cells and the vascular endothelium express the vitamin D receptor and 1-alpha hydroxylase (an enzyme involved in vitamin D metabolism).rnrnGenes overexpressed in myocardial hypertrophy, such as atrial natriuretic peptide, have vitamin D response elements and are repressed by its active form (1,25(OH)2D) in animals and in cell cultures. This active form thus inhibits cardiomyocyte proliferation. However, it stimulates proliferation of vascular smooth muscle cells and the expression of VEGF (vascular endothelial growth factor).rnrnFurthermore, 1,25(OH)2D and its analog, paricalcitol, modulate the contractile performance of isolated rat and mouse cardiomyocytes.rnrn
Immunomodulator
Over the past decade, a large body of evidence has shown that vitamin D has a protective effect against infections and autoimmune diseases. Indeed, vitamin D deficiency is a risk factor for the development of type 1 diabetes (which is an autoimmune disease), inflammatory or autoimmune diseases (multiple sclerosis, psoriasis, rheumatoid arthritis, systemic lupus erythematosus) and infections (tuberculosis, winter ear, nose, and throat (ENT) infections). But clinical studies are largely epidemiological, and randomized clinical trials have not produced definitive conclusions.rnrnAt the cellular level, vitamin D may inhibit the Th1 lymphocyte pathway by stimulating the Th2 pathway, while at the cytokine level activation of VDR (vitamin D receptor) induces both a decrease in pro-inflammatory cytokines (tumor necrosis factor alpha, interleukin 1, interferon gamma) and an increase in anti-inflammatory cytokines (notably interleukin 10).rnrn
Usages associés
Musculoskeletal effects
Vitamin D affects skeletal and smooth muscle. It appears to increase the synthesis of muscle proteins. rnrnVitamin D may prevent falls by increasing muscle strength and neuromuscular function in addition to strengthening bones.rnrnVitamin D deficiency causes muscle pain and proximal muscle weakness accompanied by symptoms such as heavy legs and rapid fatigue. rnrn
Hypoglycemic
Vitamin D is essential for normal insulin secretion. Indeed, vitamin D impacts beta cell function by ensuring control of intracellular calcium flow, which facilitates the conversion of proinsulin to insulin, insulin exocytosis and glycolysis. Demographic research has found that low vitamin D levels are associated with a higher risk of developing type 2 diabetes compared with higher vitamin D levels. Some preliminary clinical research suggests that vitamin D deficiency may contribute to impaired insulin secretion.
Usages associés
Neurological
Many researchers consider vitamin D to be a neurosteroid. Indeed, vitamin D receptors exist in the central nervous system, notably in the brain: they are found in the prefrontal cortex, the hippocampus, the thalamus, the hypothalamus and the substantia nigra. In these regions there are also enzymes capable of converting storage vitamin D, 25(OH)D, into active vitamin D or 1,25(OH)2D. However, it is not yet very clear how vitamin D might influence the neurotransmitters involved in depression. It appears that active vitamin D increases the expression of genes that enable the synthesis of norepinephrine. It may also protect the neurons that synthesize dopamine and serotonin. For example, a vitamin D deficiency could promote the development of Parkinson's disease, which is characterized by the destruction of dopaminergic neurons in the brain's substantia nigra.
Usages associés
Safe dosage
Infant from 7 to 11 months: 400 IU - 1400 IU (cholecalciferol)
The values refer to vitamin D in the form of ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3).
Child aged 1 to 10 years: 600 IU - 2000 IU (cholecalciferol)
The values refer to vitamin D in the form of ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3).
Adult aged 18 years and older: 600 IU - 4000 IU (cholecalciferol)
The values refer to vitamin D in the form of ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3).
Breastfeeding woman aged 18 years and older: 600 IU - 4000 IU (cholecalciferol)
The values refer to vitamin D in the form of ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3).
Pregnant woman aged 18 years and older: 600 IU - 4000 IU (cholecalciferol)
The values refer to vitamin D in the form of ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3).
Child aged 11 to 17 years: 600 IU - 4000 IU (cholecalciferol)
The values refer to vitamin D in the form of ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3).rnrn
Interactions
Médicaments
Atorvastatin: moderate interaction
Atorvastatin is metabolized in the intestine by cytochrome P450 3A4 (CYP3A4) enzymes. Vitamin D is believed to induce this enzyme, resulting in a decrease in the bioavailability of atorvastatin and other CYP3A4 substrates.
Calcium channel blocker: moderate interaction
High doses of vitamin D can cause hypercalcemia, which may reduce the effectiveness of calcium channel blockers (verapamil, diltiazem).
Anticonvulsants: moderate interaction
Enzyme-inducing anticonvulsants such as carbamazepine, phenytoin and phenobarbital increase the hepatic metabolism of vitamin D into inactive compounds, thereby reducing calcium absorption.
Orlistat: strong interaction
Orlistat decreases the absorption of fat-soluble vitamins, including vitamin D, thereby reducing its plasma levels in some patients.
