Vitamin D in the UK: Who Needs It and When?
Quick answer: In the UK, the sun isn't strong enough for your skin to make vitamin D between October and early March. The NHS advises everyone to consider a daily supplement of 10 micrograms (400IU) during autumn and winter, and some groups all year round.
Why vitamin D matters
Vitamin D helps your body use calcium and phosphate. Vitamin D contributes to the maintenance of normal bones, teeth and muscle function, and to the normal function of the immune system.
Most of our vitamin D is made in the skin when it's exposed to sunlight. Very few foods contain much of it, which is why the season matters so much in the UK.
Why the UK is a special case
The UK sits a long way north. From roughly October to early March, the sun is too low in the sky for its UVB rays to reach us in the amounts skin needs. Even on a bright winter day, your body makes very little.
In spring and summer, most people make enough from short periods outdoors with forearms, hands or lower legs uncovered. But office work, sunscreen, cloudy weather and covering up all reduce how much you make.
Who should take vitamin D all year
The NHS suggests these groups consider a daily supplement all year round:
- People who rarely go outdoors, for example if you're housebound or live in a care home
- People who usually cover most of their skin when outside
- People with dark skin, for example of African, African-Caribbean or South Asian background, who may not make enough even in summer
- Babies and young children (separate advice applies, so check with your health visitor)
Food sources (and why they're not enough)
| Food | Roughly how much vitamin D |
|---|---|
| Oily fish (salmon, mackerel, sardines) | One of the best food sources |
| Egg yolks | A small amount |
| Red meat and liver | A small amount |
| Fortified cereals, spreads and plant milks | Varies by brand, so check the label |
Eating these regularly helps, but it's hard to reach 10 micrograms a day from food alone, especially if you don't eat oily fish.
D2 or D3?
Most supplements use vitamin D3 (cholecalciferol), the same form your skin makes. Some vegan products use D2 or a lichen-derived D3. Both raise vitamin D levels, but many people choose D3.
Our Vitamin D3 & K2 tablets combine D3 with vitamin K2 in one daily tablet (a 90-day supply). If you'd rather chew than swallow, the D3 & K2 gummies are vegan and sugar-free.
How much is too much?
The NHS says adults shouldn't take more than 100 micrograms (4,000IU) a day. Higher-strength products like ours sit at that upper level, so take just one vitamin D product and don't double up with a multivitamin that also contains D without checking the total. If your GP has tested you and prescribed a different dose, follow their advice.
Topping up through winter? Browse immune support or take our 60-second health quiz.
FAQs
When should I start taking vitamin D in the UK?
The NHS advises considering a supplement from October to March. Many people start when the clocks go back.
Can I get enough vitamin D from a sunny holiday?
Your body can store some, but levels fall over the following months, so a winter supplement is still worth considering.
Is 4,000IU of vitamin D safe?
4,000IU (100 micrograms) is the maximum the NHS advises for adults per day. Don't combine several products that contain vitamin D.
Shop this guide
Vitamin D3 & K2 Tablets
D3 & K2 Vitamin Gummies
Women's Multivitamin & MineralsReviewed by John Lebach (Nutrition Coach)
This article is for general information only and isn't medical advice. Food supplements should not be used as a substitute for a varied, balanced diet and a healthy lifestyle. If you take prescribed medication, are pregnant or breastfeeding, speak to your GP or pharmacist before starting a supplement.
