Vitamin D supplements: doses, claims and formats
From November to February, the skin makes almost no vitamin D at European latitudes. What the studies measure, what the label may say and which formats to manufacture: an overview from the R&D team at Irati Production.
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- In winter, at the latitude of France, sunlight allows almost no vitamin D synthesis in the skin.
- ANSES sets the adult reference intake at 15 µg per day; average dietary intake in France is about 3 µg.
- According to the French Esteban survey, nearly 7% of adults and 4% of children are deficient.
- Seven health claims are authorised in the EU, from 0.75 µg per serving.
- Irati Production manufactures vitamin D as pectin-based gummies, capsules, tablets and powders.
Why the question comes back every November
Vitamin D is unusual: the body makes it in the skin when exposed to UVB rays. The French food safety agency ANSES notes that this vitamin D is stored in the liver, muscles and fat tissue, then used during winter. In November, at the latitude of Paris, the sun is too low for enough useful UVB to reach the ground.
Food does not fill the gap. According to the French INCA3 survey, cited by ANSES, adults aged 18 to 79 get 3.1 µg per day on average, far from the 15 µg reference intake. Oily fish, egg yolk and some fortified foods are the main sources. That is why searches for "vitamin D in winter" rise every autumn.
What the video did not have time to say
Vitamin D status is measured through blood levels of 25-hydroxyvitamin D. The national Esteban 2014-2016 survey by Santé publique France found that nearly 7% of adults and 4% of children were deficient, and that only about one adult in four reached a level considered adequate. There is no large-scale deficiency, but a large share of the population sits below the optimum, especially at the end of winter.
- D3 or D2: vitamin D3 (cholecalciferol) is the most common form in supplements, usually sourced from lanolin, or from lichen for a plant-based version. D2 (ergocalciferol) comes from plants or fungi.
- Fat-soluble: it is best taken with a meal containing some fat.
- An upper limit: EFSA sets the tolerable upper intake level for adults at 100 µg per day from all sources. Supplement doses are also capped by national rules.
The studies
Webb, Kline and Holick, 1988. By exposing a vitamin D precursor to sunlight, the authors showed that in Boston (42° N) no vitamin D was produced from November to February, and in Edmonton (52° N) the period without synthesis ran from October to March. Paris, at 48.9° N, lies in between.
Martineau et al., 2017, BMJ. This individual participant data meta-analysis pooled 25 randomised trials and 11,321 participants. Supplementation reduced the risk of at least one acute respiratory infection (adjusted odds ratio 0.88). The effect was clearer with daily or weekly dosing, without large spaced-out boluses, and in the most deficient people.
Manson et al., 2019, VITAL trial, NEJM. 25,871 US adults took 50 µg (2,000 IU) of vitamin D3 per day or a placebo for a median of 5.3 years. Vitamin D did not lower the incidence of invasive cancer or major cardiovascular events. A useful reminder: in broadly well-nourished people, vitamin D corrects a status; it does not prevent everything.
What the label can say
Regulation (EU) No 432/2012 authorises seven claims for vitamin D. They may be used when the daily serving provides at least 15% of the nutrient reference value, i.e. 0.75 µg (the NRV is 5 µg):
- Vitamin D contributes to normal absorption/utilisation of calcium and phosphorus.
- Vitamin D contributes to normal blood calcium levels.
- Vitamin D contributes to the maintenance of normal bones.
- Vitamin D contributes to the maintenance of normal muscle function.
- Vitamin D contributes to the maintenance of normal teeth.
- Vitamin D contributes to the normal function of the immune system.
- Vitamin D has a role in the process of cell division.
No claim allows a label to mention preventing colds, winter blues or any disease. To secure your wording, see our regulatory support.
Which format to manufacture
Vitamin D is dosed in micrograms: a few micrograms inside a capsule weighing several hundred milligrams. The key manufacturing challenge is blend uniformity, so that every unit delivers the stated dose. We prepare these premixes in our 4 blending rooms in Saumur, France.
- Pectin-based gummies: the most requested winter format, for vitamin D alone or with zinc and vitamin C.
- Capsules: ideal for combinations such as vitamin D3 + K2, in sizes 1, 0 or 00, in PET bottles, jars or doypacks.
- Tablets, including chewable tablets, for multivitamin formulas.
- Powders: vitamin D fits into a powdered drink or a broader formula.
To compare formats, see our capsule manufacturing page and our gummies manufacturing page.
Your vitamin D, made in France
Irati Production formulates and manufactures your vitamin D supplement at our manufacturing unit in Saumur.
- Pectin-based gummies, gelatin-free
- Capsules in sizes 1, 0 and 00
- Tablets, including chewable tablets
- Powders and powdered drinks
- ISO 22000 and HACCP certified, FDA registered
Our answers on vitamin D supplements
Why take vitamin D in winter?
From November to February, the skin makes almost no vitamin D in France, and food provides only about 3 µg per day on average, against a 15 µg reference intake set by ANSES.
Vitamin D3 or D2: which one for a supplement?
Vitamin D3 is the most common form. It comes from lanolin or, in a plant-based version, from lichen. Both options are possible with Irati Production.
Which claims for a vitamin D supplement?
Regulation (EU) No 432/2012 authorises seven claims, including the maintenance of normal bones and the normal function of the immune system, from 0.75 µg per serving.
What is the maximum dose of vitamin D?
EFSA sets the tolerable upper intake level for adults at 100 µg per day from all sources. Supplement doses must also comply with the national rules of each market.
Can vitamin D gummies be made without gelatin?
Yes. Irati Production manufactures pectin-based, gelatin-free gummies on its 2 gummy production lines in Saumur.
Webb AR, Kline L, Holick MF. J Clin Endocrinol Metab, 1988: PubMed 2839537. Martineau AR et al. BMJ, 2017: bmj.i6583. Manson JE et al. N Engl J Med, 2019: PubMed 30415629. Santé publique France, Esteban 2014-2016: biological measurements. ANSES: vitamin D. EFSA, 2023: tolerable upper intake level. Regulation (EU) No 432/2012: EUR-Lex.
The information in this article is general and does not constitute regulatory advice. Each formula undergoes a technical and regulatory feasibility study.