Vitamin D Dosage UK: How Much Should You Take a Day? (2026)
The NHS says to take 10 micrograms (µg) of vitamin D a day from October to March. That is 400 IU. Some people should take it all year. Do not take more than 100 µg (4,000 IU) a day.
Based on NHS advice and published research — not medical advice. If you have kidney disease or take medicine every day, ask your GP or pharmacist for your dose.
Ready to buy:
Vitabiotics Ultra Vitamin D3 400 IU4p a day at Vitabiotics’ list price (£3.95 for 96) — one tablet is 10 µg, the NHS dose. Sold by Amazon.
Which vitamin D is right for you?
You probably need less than the bottle says. 11 of the 16 best-selling adult vitamin D products on Amazon UK are 100 µg (4,000 IU): 10 times the NHS dose, and the most adults should have in a day from everything they take. Only 1 is 10 µg. For most people, the NHS says 10 µg is enough.
The dose is only half of it. If your vitamin D doesn’t fit how you take it, you may not be getting what you think.
Taking a hard tablet? You may be absorbing less than you think.
Vitamin D dissolves in fat, and most tablets have no oil in them. A small review found vitamin D in oil raised blood levels more than vitamin D in powder. This softgel is made with oil. It is 25 µg (1,000 IU): more than the NHS amount, and under the adult limit. For adults and children 11 and over.
Solgar Vitamin D3 1000 IU
9p a day at Solgar’s list price (£23.63 for 250)
Vegan? Your vitamin D probably isn’t.
Most vitamin D3 is made from lanolin, the grease in sheep’s wool. This one is labelled vegan, at the NHS dose of 10 µg.
SunVit-D3 Vegan Vitamin D3 400 IU
12p a day at SunVit-D3’s list price (£7.00 for 60)
Hate swallowing pills?
A spray goes on the inside of your cheek, so there is nothing to swallow. One spray is 25 µg (1,000 IU). The brand says it is for adults and children 13 and over.
BetterYou DLux 1000 Vitamin D Oral Spray
8p a day at BetterYou’s list price (£8.49 for 100)
Dark skin, rarely outside, or in a care home? Take it all year.
The NHS says these groups should take 10 µg every day of the year, not just from October to March, because they make less vitamin D from the sun.
Natures Aid Vitamin D3 10 µg
7p a day at Natures Aid’s list price (£5.99 for 90)
GP says your level is low?
If your GP has told you to take more, one 50 µg (2,000 IU) tablet saves taking several. Take a higher dose only if your GP or pharmacist said to. For adults.
Vitabiotics Ultra Vitamin D 2000 IU
10p a day at Vitabiotics’ list price (£9.35 for 96)
Buying for a child?
Children aged 1 to 4 should have 10 µg every day, all year. Breastfed babies need 8.5 to 10 µg a day from birth; babies having more than 500 ml of formula a day need none. If your family gets Healthy Start, vitamin drops for children under 4 are free, and so are vitamins in pregnancy and while breastfeeding. This spray is 10 µg a spray, with nothing to swallow.
BetterYou DLux Junior Vitamin D Oral Spray
8p a day at BetterYou’s list price (£7.99 for 100)
Sources: NHS vitamin D and vitamins for children pages; Grossmann & Tangpricha 2010 (oil vs powder, PMID 20425758); Silk et al. 2023 (lanolin, PMID 37817761); our read of 1,500 vitamin D labels filed in the US (16% of tablets list any oil). Best sellers: Amazon.co.uk “Best Sellers in Vitamin D” top 20, read 17 October 2026 (children’s products left out). Each product was in stock on Amazon.co.uk on 17 October 2026. Costs a day use each brand’s own UK list price, read 17 October 2026; Amazon’s price may be different.
How much vitamin D a day
| Who | A day | The most |
|---|---|---|
| Babies under 1 | 8.5–10 µg | 25 µg (1,000 IU) |
| Children 1–10 | 10 µg (400 IU) | 50 µg (2,000 IU) |
| Children 11–17 | 10 µg (400 IU) | 100 µg (4,000 IU) |
| Adults, including pregnant and breastfeeding | 10 µg (400 IU) | 100 µg (4,000 IU) |
Babies who have more than 500 ml of infant formula a day do not need extra, because formula already has vitamin D added (NHS). For children, buy a product made for their age.
For adults, many UK bottles hold 25 µg (1,000 IU). That is more than the NHS amount and well under the adult limit. The limit counts everything together: a multivitamin, cod liver oil and a vitamin D tablet all add up. Pregnant and breastfeeding women should take 10 µg a day, like everyone else.
How to take it so it works
- Take it at a time you will remember. Vitamin D dissolves in fat, so many people take it with a meal. In one trial of a single large dose, blood levels a few months later were the same with or without food (PMID: 23427007). Remembering matters more than timing.
- Oil may help. A small review of four studies found vitamin D carried in oil lifted blood levels more than dry powder (PMID: 20425758).
- Small and often, not one big dose. A tablet every day or once a week is better than a huge monthly dose, which has been linked to more falls (PMID: 42397501).
- Read IU as micrograms: divide by 40. 400 IU is 10 µg, 1,000 IU is 25 µg, 2,000 IU is 50 µg, and 4,000 IU is 100 µg, the most for adults.
Do you need a blood test first?
Usually not. At 10 µg a day you can simply follow the NHS advice. An international guideline from 2024 says healthy people with no medical reason do not need routine tests (PMID: 38828931). If you have a bone, gut or kidney condition, your GP may check your level with a 25(OH)D blood test.
What vitamin D labels say
Whether your vitamin D comes with oil depends on its shape. We checked 1,500 labels in the US government’s label database, which covers many brands that are also sold here.
| Item | Value (%) |
|---|---|
| Softgels | 90% |
| Gummies and chewables | 65% |
| Liquids and sprays | 48% |
| Capsules | 16% |
| Tablets | 16% |
This counts what US labels say, not what is in the bottle. Treat the shares as close, not exact.
Who should not follow this page
The NHS dose suits most healthy adults. Talk to your GP or pharmacist before you start if:
- You take a pregnancy multivitamin: it may already have 10 µg in it
- You have kidney disease or have had calcium kidney stones
- You have sarcoidosis, tuberculosis, an overactive parathyroid, some lymphomas, or a history of high blood calcium
- You take digoxin, a thiazide water tablet, epilepsy medicine, rifampicin, long-term steroids, orlistat or colestyramine (these can change how vitamin D works; list from the US NIH fact sheet)
- You have had weight-loss surgery
Taking too much for a long time can build up calcium in the blood. The NHS says that can weaken bones and damage the kidneys and heart (NHS).
Questions people ask
Is 4,000 IU (100 µg) of vitamin D too much?
It is the most the NHS says adults should take in a day, from everything you take together. The NHS says: “Do not take more than 100 micrograms (4,000 IU) of vitamin D a day as it could be harmful.” Most people do not need anywhere near it: the NHS says “10 micrograms a day will be enough for most people.” If you take a 100 µg tablet, do not add a multivitamin or cod liver oil with vitamin D in it.
Is 25 µg (1,000 IU) too much?
No. It is more than the NHS amount of 10 µg, but only a quarter of the 100 µg most adults should stay under. Many UK tablets and sprays come in this strength.
Do I need vitamin D in the summer?
Most people do not. From late March or early April to the end of September, most people make enough from sunlight. Take it all year if you are rarely outdoors, live in a care home, usually cover your skin outside, or have dark skin (African, African-Caribbean or south Asian background).
Is the NHS dose of 10 µg too low?
Some supplement brands say so. The NHS says “10 micrograms a day will be enough for most people.” In the two biggest trials, most people already had enough, and extra vitamin D did little for them. A 2026 analysis of UK Biobank data suggests people whose levels are low may gain more (PMID: 41719624). If a blood test shows your level is low, your GP may tell you to take more.
Should I take D3 or D2?
D3. It is what almost every UK tablet and spray contains (cholecalciferol). When researchers pooled the daily-dose studies, D2 lifted blood levels roughly 40% less (PMID: 37865222).
Related guides
- Best vitamin D supplements in the UK — our picks
- Vitamin D2 vs D3 — why D3 raises blood levels more
- Vitamin D with or without K2
- Vitamin D side effects
Sources
- NHS. "Vitamin D." Page last reviewed 3 August 2020. nhs.uk
- NHS. "Vitamins for children." nhs.uk
- NHS Healthy Start. healthystart.nhs.uk
- NIH Office of Dietary Supplements. "Vitamin D: Fact Sheet for Health Professionals" (medicines). ods.od.nih.gov
- Demay MB, et al. "Vitamin D for the Prevention of Disease: An Endocrine Society Clinical Practice Guideline." J Clin Endocrinol Metab. 2024. PMID: 38828931
- Grossmann RE, Tangpricha V. "Evaluation of vehicle substances on vitamin D bioavailability: a systematic review." Mol Nutr Food Res. 2010. PMID: 20425758
- Dawson-Hughes B, et al. "Meal conditions affect the absorption of supplemental vitamin D3 but not the plasma 25-hydroxyvitamin D response to supplementation." J Bone Miner Res. 2013. PMID: 23427007
- Dalamaga M, et al. "From the Vitamin D Paradox to Precision Nutrition: Targeted Supplementation, Assay Pitfalls, and Clinical Decision-Making." Curr Nutr Rep. 2026. PMID: 42397501
- Silk G, et al. "Are vegans being overlooked in our prescribing practices: An orthopaedic perspective from Bristol, United Kingdom." J Clin Orthop Trauma. 2023. PMID: 37817761
- Wang Y, et al. "Impact of vitamin D supplementation on all-cause mortality: Randomized trials revisited." Clinical Nutrition. 2026. PMID: 41719624
- van den Heuvel EG, et al. "Comparison of the Effect of Daily Vitamin D2 and Vitamin D3 Supplementation on Serum 25-Hydroxyvitamin D Concentration." Adv Nutr. 2024. PMID: 37865222
- NIH Dietary Supplement Label Database (DSLD) v9 — the US labels behind our label study. dsld.od.nih.gov