Vitamin B3: Skip it and eat salmon, tuna, or beets instead.

Vitamin B3: Skip it and eat salmon, tuna, or beets instead.
For years, Vitamin B3 was promoted to treat everything from Alzheimer's to heart disease. But recent studies have called for an end to the over-prescription of the nutrient.

A large 2014 study of more than 25,000 people with heart disease found that putting people on long-acting doses of Vitamin B3 to raise their levels of "good," or HDL, cholesterol didn't reduce the incidence of heart attacks, strokes, or deaths.

Plus, people in the study who took the B3 supplements were more likely than those taking a placebo to develop infections, liver problems, and internal bleeding.