Library

Vitamin D: what the large trials showed, and what they did not

For a while vitamin D became one of the best-selling supplements in the world, with promises for the heart, cancer and immunity. When it was tested in a large trial, the results were more modest.

3 November 2026 / 5 min read

Multivitamins: is a pill a day worth it?

Many people take a multivitamin every morning "just in case". Large trials show that for most healthy adults the benefit is small or unclear. But there are also important exceptions.

3 November 2026 / 2 min read

Fish oil and omega-3: why capsules did not repeat the benefit of fish

Old studies of populations that ate a lot of fish suggested that omega-3 protects the heart. When capsules were tested in large trials, the picture turned out to be much more complicated.

3 November 2026 / 2 min read