Vitamin D
UK guidance is that everyone should consider a daily supplement of 10 micrograms (400 IU) of vitamin D during autumn and winter.
Short answer UK guidance is that everyone should consider a daily supplement of 10 micrograms (400 IU) of vitamin D during autumn and winter. People who get little sun, cover their skin or have dark skin should consider taking it all year.
Why vitamin D matters
Vitamin D helps regulate calcium and phosphate. It contributes to the maintenance of normal bones, teeth and muscle function, and to the normal function of the immune system. From late March to September most people make enough from sunlight; in a British winter the sun is too weak.
How much, and the upper limit
| Group | Daily amount |
|---|---|
| Adults and children over 4 | 10 micrograms (400 IU) |
| Babies under 1 | 8.5 to 10 micrograms |
| Upper limit for adults | 100 micrograms (4,000 IU) |
More is not better. Too much over a long period can raise calcium levels and harm bones, kidneys and heart.
D2, D3 and K2
D3 is the form made in skin and is the commoner supplement; D2 is plant-derived. Vitamin K2 is often sold alongside. Vitamin K contributes to normal bones, but UK guidance does not ask you to pair the two.
In a multivitamin
Most multivitamins contain vitamin D, so check before adding a separate tablet. Oriflame's Multivitamin & Mineral includes it among its 12 vitamins.
Related pages
- Vitamins and mineralsMost people can get the vitamins and minerals they need from a varied diet.
- Pregnancy vitamins and supplementsUK advice is to take 400 micrograms of folic acid daily from before conception until 12 weeks, and 10 micrograms of vitamin D daily throughout pregnancy.
- Immune support supplementsNothing 'boosts' the immune system.
Keep exploring
- Multivitamins for men
- Ashwagandha
- Marine collagen
- Protein powders and shakes
- Oriflame Wellosophy supplements
- Bovine collagen
Questions people ask
How much vitamin D should I take?
10 micrograms a day in autumn and winter, per UK guidance.
Can I take vitamin D all year?
Yes, at 10 micrograms, and some groups are advised to.
What is the best time to take vitamin D?
Any time; with food containing some fat may help absorption.
Can I take this with medication?
Ask a pharmacist or GP first; some supplements interact with medicines.
Do supplements replace a balanced diet?
No. They are meant to add to a varied diet, not stand in for one.
Sources
- NHS: Vitamin D (opens in a new tab)
- Great Britain nutrition and health claims register (opens in a new tab)
Checked 9 October 2026.