Niacin
Why you need it: Niacin, like its fellow B vitamins, is important for converting food into energy. It also helps the digestive system, skin, and nerves to function properly.
Where to get it: Dried yeast is a top source of niacin, but for something more appetizing, try peanuts or peanut butter; one cup of raw peanuts contains 17.6 mg, more than 100% of your DV. Beef and chicken liver are particularly niacin-rich, as well.