This is what vitamin D supplements actually consist of

The British health service NHS has advised Britons to take daily vitamin D supplements during the autumn and winter until around March, as we are unable to produce enough vitamin D ourselves due to the lack of sun.

The vitamin is essential for the health of bones, gums and muscles. A lack of vitamin D can cause rickets in children and adults, and a deficiency can lead to bone pain due to osteomalacia.

Given the chance, our skin usually produces enough to keep us healthy through sunlight.

But I've always wondered how vitamin D, which is also found in foods like fatty fish, egg yolks, red meat and liver, gets into a capsule – it's pretty difficult to put sunshine, literally, into a bottle.

Vitamin D supplements can be made from a variety of sources and are available in two forms.

“In foods and dietary supplements, vitamin D occurs in two main forms, D2 (ergocalciferol) and D3 (cholecalciferol),” writes the US research agency National Institutes of Health.

Ergocalciferol is derived from irradiated mushrooms (according to the peer-reviewed journal database Science Direct). A 2023 article explains that these are “fresh or dried mushrooms grown using ultraviolet radiation or sunlight.”

However, things get a little more interesting with cholecalciferol.

The National Institute of Health states that “Vitamin D3 is typically produced by irradiating 7-dehydrocholesterol from lanolin, which is obtained from the wool of sheep.”

In a sense, both methods are like bottling sunlight. More specifically, they capture the effects of sunlight on animal and plant cells in a way that is available to our bodies.

Vitamin D3 (cholecalciferol) is produced by our skin when it comes into contact with sunlight, explains the health information site Healthline.

Vitamin D (ergocalciferol) is only produced when plants such as fungi react to sunlight.

Although they “come from different sources, they work in very similar ways,” Lloyd's Pharmacy said on its website.

The main difference is that one is plant-based and the other is an animal product.

Both are effective in treating vitamin D deficiency when taken in the correct dose (adults should never take more than 100 micrograms). [mcg] per day, while children under 10 years of age should not receive more than 50 mcg; 10 mcg is enough for most people).

So as the colder months begin, remember to choose the type you prefer to keep your gums, skin, bones and muscles healthy.