The NHS has encouraged millions of Brits to take vitamin D but one expert has warned people to look out for potential side effects.
An NHS spokesman posted on X: "From October to March we can't make enough vitamin D from sunlight, so to keep bones and muscles healthy, it's best to take a daily 10 microgram supplement of vitamin D. You can get vitamin D from most pharmacies and retailers."
Sunlight is essential for vitamin D production, as UVB rays from the sun help support a chemical reaction in the skin which produces the nutrient.
This process converts 7-dehydrocholesterol into vitamin D3, which plays an important role in calcium absorption, bone health, and immune system support.
The government recommends that everyone consider taking a daily vitamin D supplement of 10 micrograms (400 IU) during the autumn and winter months when the sunlight isn't strong enough for the body to produce adequate vitamin D.
While experts agree that many should be taking supplements, the guidance does come with an important precaution.
Tobias Mapulanga, biomedical scientist and co-founder of Repose Healthcare, has issued a warning about symptoms you may need to watch for.
Mapulanga said: "As the NHS encourages vitamin D in winter, many people are reaching for bottles in the darker months and accidentally overshooting, then blaming the fallout on seasonal bugs; when constant thirst and needing the loo more often, queasiness, tummy pain or constipation, headaches or brain fog, and new aches or cramps appear soon after increasing your intake or adding sprays or gummies, that points to a supplement backfiring.”
"The stakes are clear: the right amount supports you, but doubling up can turn a well-meant routine into feeling worse rather than better,” the expert added.
If you are taking Vitamin D supplements, some signs that may indicate its excess include: