People usually associate dark circles beneath the eyes with a lack of sleep. While this might contribute to the appearance of shadowed eyes, it usually is not the only explanation. It is more likely that the dark circles are caused by a deficiency in your diet. In other words, if you aren't getting enough of the right vitamins and minerals, you may end up wearing the evidence of your less-than-ideal eating habits on your face.
The National Heart and Blood Institute defines anemia as "a condition in which your blood has a lower than normal number of red blood cells." Poor iron intake could result in the development of iron-deficiency anemia, which will leave you feeling as weak and tired as you look. A common side-effect of iron-deficiency anemia is the appearance of dark circles under the eyes. If your eyes are ringed in shadows, try evaluating your diet. Make sure you are eating enough iron-rich foods, such as fortified cereals, eggs, green leafy vegetables like spinach, broccoli, beef and especially liver. Not only will you feel better, you will look better too.
If you believe you are getting enough iron in your diet, the dark circles under your eyes could be caused by a deficiency of vitamin C. According to the U.S. National Library of Medicine and the National Institutes of Health, this essential vitamin is instrumental in the growth and repair of tissues, forming collagen, healing processes and maintaining healthy body systems. Because the body does not produce vitamin C on its own, it must be consumed from outside sources. Again, your best options are a variety of fruits and vegetables. Citrus fruits, cauliflower, red peppers and potatoes are excellent sources of vitamin C and should be incorporated into your daily diet.
If your iron and vitamin C intake is adequate but you still have unsightly circles, a deficiency of vitamin K in your diet could be the cause. The U.S. National Library of Medicine and the National Institutes of Health states that vitamin K "plays an important role in blood clotting." Simply, blood cannot clot without it. If blood vessels around the eyes become dilated because of a lack of vitamin K, it could lead to the appearance of dark circles. Some of the same foods you eat for iron are also good sources of vitamin K (e.g., leafy green vegetables, fortified cereals, broccoli and liver).
Last, but certainly not least, if dark circles under your eyes are making you look fatigued, perhaps it is because you genuinely are fatigued. Perhaps you aren't suffering from a deficiency of vitamins or minerals; you're suffering from a deficiency of adequate sleep. There isn't a diet or a supplement in the world that can replace your body's need for rest. Be sure that you are getting enough.