A significant portion of the UK population is failing to get a crucial nutrient, with one in five Britons not receiving enough vitamin D. This comes despite clear NHS guidance advising everyone over the age of four to take a daily 10-microgram supplement during the autumn and winter months. For children aged one to four, the recommendation is year-round.
The Critical Role of Vitamin D
The reasons for ensuring adequate intake are compelling. Vitamin D is essential for warding off fatigue and common colds, while also maintaining strong bones, teeth, and muscles. It can even help reduce hair loss. Importantly, a 2025 US study provided further impetus, finding that the vitamin can slow visible signs of ageing and decrease the risk of developing dementia.
Which? Puts 30 Supplements to the Test
Faced with a crowded market, the consumer champion Which? undertook a rigorous scientific analysis of 30 different vitamin D products. Their experts assessed each supplement's 'bioavailability' – how well it is absorbed by the body – by scrutinising labels. They also measured the precise dosage per serving and checked for any unnecessary additives.
To ensure complete accuracy, samples were sent to a laboratory for high-performance liquid chromatography testing. This process verified that the ingredients inside each bottle perfectly matched what was stated on the label. As a not-for-profit organisation, all of Which?'s earnings are reinvested to advocate for consumers, adding weight to their impartial findings.
Top Picks for Every Preference
The investigation revealed standout products across different formats, catering to various needs and budgets.
BEST DROPS: Nutravita Vitamin D3 1000IU Drops
This option proved unbeatable for value. A 60ml bottle, providing a staggering 2,000 doses, costs from £15.99, working out at less than 1p per dose. Each serving delivers 25 micrograms of vitamin D. The drops contain coconut oil to enhance absorption and have no unnecessary additives. The only minor drawback noted was that some testers found the pipette a little fiddly to use.
BEST GELS: Solgar Vitamin D3 1000IU Softgels
For those who prefer a capsule, these softgels scored perfectly in lab tests. Priced from £23.63 for 250 capsules (under 11p each), they also offer 25 micrograms per serving. The safflower oil content ensures great bioavailability, and the soft coating makes them easier to swallow than standard tablets. However, they contain bovine gelatine and vitamin D3 sourced from fish oil, making them unsuitable for vegetarians and vegans.
BEST SPRAY: BetterYou Vitamin D 1000IU Daily Oral Spray
Ideal for anyone who struggles with pills, this spray offers a simple and effective alternative. A 15ml bottle (100 doses) starts at £7.95, around 8p per dose. It delivers 25 micrograms of vitamin D directly into the bloodstream, contains no unnecessary additives, and was highly rated by testers. Its natural peppermint oil flavouring was enjoyed by many, though some may need time to acquire the taste.
The clear message from the research is that maintaining vitamin D levels is vital for long-term health, and with a range of rigorously tested, effective supplements now identified, there is a suitable option for every consumer in the UK.
