Ingredients

Vitamin D (cholecalciferol)

Vitamin D is one of the best-selling food supplements in European parapharmacies. EU law fixes the forms that may be used and the claims that may be made. Maximum doses are left to national rules, and higher-dose products are often medicines.

At a glance

Forms permitted in food supplements

Cholecalciferol (vitamin D3) and ergocalciferol (vitamin D2), Directive 2002/46/EC Annex II

Nutrient reference value (labelling)

5 µg per day (Regulation (EU) No 1169/2011, Annex XIII)

Units

1 µg = 40 IU; 10 µg = 400 IU; 25 µg = 1,000 IU

EFSA tolerable upper intake level

100 µg/day for adults and adolescents aged 11–17; 50 µg/day for children aged 1–10; lower values for infants

Regulatory class

Food supplement ingredient; also the active substance in authorised medicines

What it is

Vitamin D is a fat-soluble vitamin. The body makes it in the skin under UVB light and also takes it in from a small number of foods. Supplements generally use vitamin D3 (cholecalciferol), often derived from lanolin, or vitamin D2 (ergocalciferol), produced from yeast or fungi. Products labelled vegan may use D2 or D3 from lichen. Because sun exposure at northern latitudes is limited in winter, several national public-health bodies recommend vitamin D supplementation for particular groups, such as infants. Those recommendations are national and change over time.

Regulatory status

In food supplements, vitamin D falls under Directive 2002/46/EC, which permits it and lists the permitted forms. There is no harmonised EU maximum amount per daily dose. Member States set their own limits or assess products case by case, which is why products with the same brand name may contain different amounts in different countries. Products with higher doses, or presented for treating or preventing deficiency, are commonly authorised as medicinal products and may be sold only through pharmacies. See borderline products.

EFSA reviewed the tolerable upper intake level in 2023 and confirmed 100 µg (4,000 IU) per day for adults, including during pregnancy and breastfeeding, and for adolescents aged 11–17. The level for children aged 1–10 is 50 µg per day. The upper level is the maximum chronic daily intake from all sources considered unlikely to cause adverse effects. It is not a recommended dose.

Authorised health claims

The EU Register of nutrition and health claims lists authorised claims for vitamin D, including that it contributes to the normal absorption and use of calcium and phosphorus, to normal blood calcium levels, to the maintenance of normal bones, muscle function and teeth, and to the normal function of the immune system. A children's development claim (Article 14) concerns normal growth and development of bone in children. A disease risk-reduction claim concerns the risk of falling in people aged 60 and over. Each claim may be used only under the conditions of use in the Register, including a minimum content per daily portion.

Safety considerations

Excessive vitamin D intake over time can raise blood calcium (hypercalcaemia), with effects on the kidneys and heart. Reported cases usually involve very high doses, often from dosing errors or from combining several products. Vitamin D may interact with some medicines and is relevant in conditions affecting calcium metabolism. People taking prescription medicines, or with kidney disease or sarcoidosis, should discuss supplementation with a pharmacist or physician. This page does not give dosing advice.

Frequently asked questions

What is the maximum vitamin D dose in EU food supplements?

There is no harmonised EU maximum. Member States set their own limits or assess products case by case. Separately, EFSA has set a tolerable upper intake level of 100 µg (4,000 IU) per day from all sources for adults.

How do I convert vitamin D µg to IU?

Multiply micrograms by 40: 10 µg = 400 IU, 25 µg = 1,000 IU, 100 µg = 4,000 IU.

Is vitamin D a food supplement or a medicine?

It can be either. Lower-dose products presented as supplementing the diet are usually food supplements. Higher-dose products, or those presented for treating deficiency, are often authorised as medicines.

What health claims can vitamin D supplements make?

Only the claims authorised in the EU Register, under their conditions of use — for example that vitamin D contributes to the maintenance of normal bones and to the normal function of the immune system.

Last reviewed: October 2026.