Vitamin D in winter: who should take it and how much
Your body makes vitamin D when sunlight falls on your skin. From late March or early April to the end of September most people get enough that way and from food. In autumn and winter the sun in the UK is too weak, so the NHS advises everyone to consider a supplement.
How much
- Adults and children over 1: 10 micrograms a day, sometimes written as 400 IU, in autumn and winter.
- Babies up to 1 year: 8.5 to 10 micrograms a day all year if they are breastfed, or have less than 500ml of infant formula a day. Formula is already fortified.
- Children aged 1 to 4: 10 micrograms a day all year.
Who should take it all year round
Some people do not get enough from sunlight even in summer. The NHS advises 10 micrograms a day all year if you:
- are rarely outdoors, for example if you are frail or housebound
- live in a care home
- usually cover most of your skin when outside
- have dark skin, for example if you are of African, African-Caribbean or South Asian background
More is not better
Taking too much vitamin D for a long time can be harmful. Unless a doctor advises a different amount, do not take more than:
- 100 micrograms (4,000 IU) a day for adults, including in pregnancy and when breastfeeding, and for children aged 11 to 17
- 50 micrograms (2,000 IU) a day for children aged 1 to 10
- 25 micrograms (1,000 IU) a day for babies under 12 months
Some medical conditions mean you need less, so check with your doctor or with us if you have a long-term condition. If your doctor has prescribed a different dose, follow that.
Food helps, but rarely enough
Oily fish such as salmon, sardines, herring and mackerel, red meat, egg yolks and fortified foods such as some spreads and breakfast cereals all contain vitamin D. Liver does too, but avoid it in pregnancy. Cows' milk in the UK is not usually fortified, so it is not a good source.
Choosing a supplement
A simple 10 microgram supplement is all most people need. If you already take a multivitamin, check the label before adding another product, so you do not double up. Ask at the counter in Brighton and we will help you pick one that suits you and anything else you take.
Common questions
Do I need it in summer?
Most people get enough from sunlight between late March and the end of September. The groups above should carry on all year.
Can children have adult supplements?
Check the dose. Children aged 1 to 10 should not have more than 50 micrograms a day, and products made for children make the right amount easier.
Sources
Last checked against this source on 22 October 2026.
