You know that "feel-good" sensation you get during a long, hot, lazy summer day? Things may or may not be going well in life, ...

What is vitamin D3? Your body creates this vitamin naturally when exposed to sunlight. In the winter, however, we tend to stay inside more, making it harder to get the proper amount of D3.

Out of 17 vitamin D supplements, these eight brands made our best list. (SaVanna Shoemaker, RD) ...