Vitamin D supplements seem to be all the rage for health and longevity these days. How do we know if we really need them? We asked our chief medical officer, Sohaib Imitiaz, MD, to break it down. Q: ...

Sweeney is a contributor for TIME. Sweeney is a contributor for TIME. Vitamin D does a lot for your body, supporting strong bones, muscle movement, your immune system, and more. Taking a vitamin D ...