The link between vitamin C and mood might seem surprising, but people who have vitamin C deficiency often feel fatigued or depressed. Studies of hospitalized patients — who often have lower than normal vitamin C levels — have 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. A study of high school students indicated that vitamin C lowered anxiety levels, and other studies have shown mood-elevating effects from taking vitamin C.
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 to your doctor before taking any supplement.