Is taking vitamin d (cholecalciferol) 800iu & eating good for a 32 y/o man who exercises?

Vitamin D : Deficiency has become an epidemic in the United States. However, one should not on their own supplement without knowing their levels as a, d, e, and k are retained by the body. This is a general statement. Likely, the 800 i.U is not going to overdose you, however, it might actually not be enough. Normal levels are 30-100 in most labs. Get a baseline so you know if taking too little or too much.