You could have circles under your eyes for any number of reasons. The Mayo Clinic website lists pigmentation irregularities, allergies and even the bad habit of rubbing your eyes as possible causes. Dark circles can also be hereditary and might worsen with age. Although there isn't much you can do about those things, you might be able to treat under-eye circles that are related to vitamin deficiencies.
An iron deficiency can cause dark under-eye circles. Because iron carries oxygen, a lack of it can mean that the cells don't get enough oxygen. This can give the cells under your eyes a dark appearance. Also, iron-deficiency anemia can make your skin look pale and ashy. As a result, any dark circles under your eyes -- even those caused by another condition -- can look even darker. If you correct the iron deficiency, your skin will regain a healthy color that will either fix or hide the circles, depending on what's causing them.
Vitamin K is a common ingredient in creams used to treat skin aging and under-eye problems, including dark circles. Vitamin K is an anti-coagulant that can help strengthen blood vessels and keep them from getting damaged. A vitamin K deficiency can cause capillaries to break, which can worsen the appearance of dark circles. Good sources of vitamin K include soybean and canola oil, broccoli, kale and Swiss chard.
Vitamin E is an anti-oxidant that can help keep the skin looking fresh and young. This, in turn, might help to reduce wrinkles and dark circles. It can also lessen any puffiness that might cause the circles to be more prominent. Applying vitamin E oil directly under your eyes is a good option, but you can also take vitamin supplements or eat more foods rich in vitamin E, such as green leafy vegetables, nuts and seeds.
Other Vitamins and Minerals
Any vitamin or mineral that helps your skin might also help to improve your under-eye appearance. This is because young-looking skin is less likely to be puffy or to show imperfections. For example, vitamins A and C can help reduce fluid build-up and tone the skin.