The D-Health trial
Vitamin D in your body comes from exposure to the sun or from your diet. Having a sufficient amount of vitamin D in your blood stream is important for maintaining healthy bones. There is some evidence that it might also reduce risks of diseases such as diabetes, heart disease, multiple sclerosis and some cancers, but this is uncertain.
To fully understand the effects of increasing blood levels of vitamin D we need to conduct large trials of taking vitamin D supplements.
You may be able to take part in one of the world's largest vitamin D trials.