Allergies, too much fun in the sun, too little sleep, inherited pigmentation abnormalities and poor circulation are some of the things responsible for those telltale, bluish half-moons under your peepers. Just the aging process itself makes blood vessels under the eyes more prominent. Combine this with the effects of gravity, and puffy lids above cast dark shadows below the eyes. There's no surefire cure for dark circles, but if the tea bag and cucumber routines are a bust, take heart and consider making vitamin K part of your daily regimen, inside and out.

Healthy kale and quinoa salad

Meet Vitamin K

Vitamin K represents a group of fat-soluble vitamins, meaning they're absorbed with dietary fats and stored by fatty tissue in the body for later use. Vitamin K is needed to manufacture prothrombin, a key blood clotting factor and protein necessary for bone mineralization. Because vitamin K is involved in blood clotting, it's thought to assist in wound healing and bruising and reduction of visible signs of skin discolorations, scars and dark circles under the eyes.

Eat More of These Foods

Vitamin K1, also known as phylloquinone, occurs naturally in plants and is converted into vitamin K2 in the small intestine and stored in the liver and fatty tissue. Excellent sources include kale, spinach, collard greens, turnips, broccoli, Brussels sprouts and parsley. Vitamin K2, also referred to as menaquinone and MK-4, is found in animal products, namely meat, eggs, cow’s milk and cheese. It's also abundant in natto, a Japanese dish made from fermented soybeans traditionally served at breakfast.

Try Topical Treatments

Applied to the skin, vitamin K appears to improve dark circles in the same way it helps bruises to heal when taken internally. In fact, doctors frequently recommend creams with vitamin K to patients post-surgery to counter swelling and bruising. In one study, researchers tested the effects of a topical treatment consisting of vitamin K and caffeine in a base of emu oil on under-eye circles. Eleven women participated, each given a pad coated with this mixture to place under the right eye and a pad damp with plain water under the left, for one hour each night. After one month, all of the women had a marked reduction in dark circles. Added bonuses: fewer wrinkles and improved elasticity.

Get Your Daily Dose

Adult women need between 90 and 120 milligrams of vitamin K per day. Most people get enough of this vitamin through a balanced diet that includes green, leafy vegetables and healthy fats. However, some people benefit from supplementation, especially those with a condition that presents a malabsorption issue, such as celiac disease or cystic fibrosis. Vitamin K is available alone or in combination formulas, typically with vitamin D, calcium and magnesium.

Consider These Precautions

Although vitamin K has low toxicity, it can interfere with blood-thinning medications, anticonvulsants, weight-loss drugs and certain antibiotics. This vitamin also increases the effects of herbs that lower blood sugar, such as ginseng, fenugreek and devil's claw. Note, too, that cholesterol-lowering drugs inhibit fat absorption, making absorption of vitamin K difficult. If you take any prescription medications or supplements, or have a chronic condition that inhibits nutrient absorption, talk to your doctor before taking vitamin K supplements.