Best Vitamin D Supplement in the UK (2026): Complete Buying Guide
The best vitamin D for most people in the UK is Vitabiotics Ultra Vitamin D3 400 IU: one tablet is 10 µg (400 IU), the dose the NHS advises from October to March, at 4p a day at Vitabiotics’ list price (£3.95 for 96). Amazon sells it itself. Do not take more than 100 µg (4,000 IU) a day (NHS).
You probably don’t need high strength. Most best sellers on Amazon UK are far stronger than the NHS dose: 11 of the top 16 adult products are 100 µg (4,000 IU) a tablet or spray. That leaves no room for a multivitamin or cod liver oil on top.
Informational comparison of UK products and label doses — not medical advice.
How to choose
| Your situation | Our pick | A day | Why |
|---|---|---|---|
| Most people (the NHS dose) | Vitabiotics Ultra Vitamin D3 400 IU | 4p | 10 µg, sold by Amazon. The label says one or two a day; one is the NHS dose. |
| Want a softgel made with oil | Solgar Vitamin D3 1000 IU | 9p | 25 µg in safflower oil, for adults and children 11 and over. Contains fish; not vegetarian. |
| Vegan | SunVit-D3 Vegan Vitamin D3 400 IU | 12p | 10 µg, labelled vegan. Most vitamin D3 is made from sheep’s wool (lanolin). |
| No pills | BetterYou DLux 1000 Vitamin D Oral Spray | 8p | 25 µg a spray, inside the cheek. The brand says adults and children 13 and over. |
| GP says your level is low | Vitabiotics Ultra Vitamin D 2000 IU | 10p | 50 µg. For adults, and only if your GP or pharmacist told you to take more. |
| Children | BetterYou DLux Junior Vitamin D Oral Spray | 8p | 10 µg a spray. Families on Healthy Start get children’s vitamin drops free. |
All the UK vitamin D3 products we checked
| Product | Dose | A day | Buy |
|---|---|---|---|
| Vitabiotics Ultra Vitamin D3 400 IU (96 tablets) | 10 µg 400 IU | 4p | See on Amazon |
| Natures Aid Vitamin D3 10 µg (90 tablets) | 10 µg 400 IU | 7p | See on Amazon |
| BetterYou DLux Junior Vitamin D Oral Spray (15 ml) Sold on Amazon by checked 2026-10-19 | 10 µg 400 IU | 8p | See on Amazon |
| SunVit-D3 Vegan Vitamin D3 400 IU (60 tablets) Sold on Amazon by Sunvit-D3 Vitamins | 10 µg 400 IU | 12p | See on Amazon |
| BetterYou DLux 1000 Vitamin D Oral Spray (15 ml) Sold on Amazon by Great Deals GB | 25 µg 1,000 IU | 8p | See on Amazon |
| Solgar Vitamin D3 1000 IU (250 softgels) | 25 µg 1,000 IU | 9p | See on Amazon |
| Vitabiotics Ultra Vitamin D 2000 IU (96 tablets) | 50 µg 2,000 IU | 10p | See on Amazon |
Want the full NHS dose by age, and how to take it? See the UK vitamin D dosage guide.
What 948 vitamin D labels say
The UK shelf is not the only one that runs strong. We read 948 vitamin D labels filed with the US government’s label database, from 274 brands. Many of those brands sell in the UK too.
The typical label is 2.5 times the NHS amount, and the top tenth sit at or above the 4,000 IU (100 µg) limit the NHS also uses. That limit is not a poisoning line. It is the most that is known to be safe every day, from everything you take.
The letter on the label is rarely the problem: 835 of the 948 labels we read declare D3, and only 50 declare D2. The number on the front is what to check.
Method: labels from the NIH Dietary Supplement Label Database (DSLD) v9, read 2026-09-16. This shows what is on offer in the US, not what people buy, and not the UK shelf; for the UK shelf, see the best-seller count above.
What to look for (and avoid)
Buy D3, not D2
Almost every UK vitamin D is D3 (cholecalciferol). If a label says D2 (ergocalciferol), pick another: in studies that gave a daily dose, D2 raised blood levels about 40% less than D3 (van den Heuvel 2024, PMID 37865222).
D3 + K2 combos
Many UK best sellers add vitamin K2 (MK-7). The NHS gives no advice to take K2 with vitamin D, and most people do not need it. K2 can interact with warfarin, so ask your pharmacist first if you take a blood thinner.
Softgel or tablet: take it with food either way
Vitamin D dissolves in fat. A softgel carries its own oil; most tablets do not. Whichever you buy, take it with a meal.
UK guidance
- NHS: 10 µg (400 IU) a day for everyone over 1 year old from October to March, and all year if you get little sun or have dark skin. Adults and children aged 11 and over: no more than 100 µg (4,000 IU) a day. NHS, vitamin D
- Children 1 to 4: 10 µg a day. Breastfed babies: 8.5 to 10 µg a day. NHS, vitamins for children
- Healthy Start: eligible families get free vitamin drops for children under 4 and tablets in pregnancy. healthystart.nhs.uk
Frequently asked questions
What is the best vitamin D supplement in the UK?
For most people: Vitabiotics Ultra Vitamin D3 400 IU. One tablet is 10 µg (400 IU), the NHS dose, at 4p a day at Vitabiotics’ list price, and Amazon sells it itself. If you want a softgel made with oil: Solgar Vitamin D3 1000 IU (25 µg). Vegan: SunVit-D3 Vegan Vitamin D3 400 IU. No pills: BetterYou DLux 1000 Vitamin D Oral Spray.
Is high strength vitamin D better?
Not for most people. The NHS says “10 micrograms a day will be enough for most people.” 100 µg is safe for adults, but it is the daily most from everything you take. Take a higher dose only if your GP has told you to.
Should I buy vitamin D3 with K2?
Most people do not need it. The NHS gives no advice to take K2 with vitamin D. Vitamin K2 can interact with warfarin, so ask your pharmacist first if you take a blood thinner. Vitamin D with or without K2.
More on vitamin D
- UK dosage guide — the NHS dose by age, and how to take it
- D2 vs D3 — how the two forms compare
- Vitamin D + K2 — when K2 matters
Sources
- NHS. "Vitamin D." nhs.uk
- NHS. "Vitamins for children." nhs.uk
- van den Heuvel EG, et al. "Comparison of Vitamin D2 and D3 Supplementation." Adv Nutr. 2024. PMID: 37865222
- NIH Dietary Supplement Label Database (DSLD) — the US labels behind our label census. dsld.od.nih.gov
- Best sellers: Amazon.co.uk “Best Sellers in Vitamin D” top 20, read 17 October 2026 (children’s products left out).