Vitamin D supplements don’t prevent heart disease or cancer
In the largest clinical trial yet, taking a supplement or a placebo made little difference
![bottle of vitamin D](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2018/11/110918_MF_vitamin-d_feat.jpg?fit=860%2C460&ssl=1)
D DUD? A large clinical trial investigated whether taking a daily vitamin D supplement could help prevent heart problems and cancer.
Mark Lennihan/AP Photo