Vitamin D

Vitamin D products across every format stocked — softgels, capsules, liquids and oral sprays, tablets and gummies — including combined vitamin D and K2 formulas.

Two label details decide most purchases. The first is strength, which is printed in both international units and micrograms: 1,000 IU is 25µg, 2,000 IU is 50µg and 4,000 IU is 100µg, so converting is the only way to compare two products fairly. The second is the form — almost everything here is D3 (cholecalciferol) rather than D2, and D3 is most commonly derived from lanolin, so if you follow a vegan diet look for the lichen-derived versions, which are stated on the product page.

Because vitamin D is fat-soluble, it is usually sold in an oil base, which is why softgels and liquid drops dominate this category. Oral sprays and drops suit anyone who does not want to swallow a capsule and make small doses easy to measure, which is also why they are the usual format for children's products — follow the pack directions for age rather than splitting an adult dose. Combined D3 and K2 products put both fat-soluble vitamins in one capsule. Vitamin D is included in most multivitamins, so check the panel before stacking. See vitamins for the full range and liquids & drops for measurable formats.

Order by 3pm Monday to Friday for same-day dispatch. Tracked UK delivery is a flat £5, and free on orders over £120.