The link between vitamin C and mood might seem surprising, but people who have vitamin C deficiency often feel fatigued or depressed. Some studies have shown that people who have lower than normal vitamin C levels found that their mood improved after they received vitamin C.

But even for people who aren't known to have low vitamin C levels, taking a vitamin C supplement might help mood. In some studies, participants reported that vitamin C lowered their anxiety levels.

More research is needed. But in the meantime, eat plenty of fruits and vegetables rich in vitamin C, such as oranges and red peppers. If you also take a supplement, try not to exceed the upper limit of 2,000 milligrams of vitamin C a day. As always, talk with your doctor before taking any supplement.