Bruising occurs when tiny capillaries beneath the skin break, leaking blood under the skin. Injuries cause bruising, but spontaneous bruising can also occur if you have a medical condition, such as hemophilia, or if you take medications that interfere with the blood's ability to clot, such as warfarin. Although a lack of vitamins C or K could cause bruising, vitamin deficiencies are not often a cause. Some alternative-health websites claim that vitamin E might help bruises heal more quickly, although it's better known for potentiating the action of blood thinners, which can increase bleeding. Unexplained bruising requires medical evaluation.
Vitamin K, so-named because the K stands for the German word koagulation, plays an essential role in clotting factors that help stop bleeding. You can get it in your diet, and it can be synthesized in your gut from bacteria. Newborns have sterile intestines. Because they don't make vitamin K for a few days, they're given an injection of vitamin K to prevent bleeding. Vitamin K deficiency is rare in adults. Taking an antibiotic for more than a month, however, can cause a deficiency, according to the University of Alabama. And if you take warfarin, an anti-coagulant, you develop a functional vitamin K deficiency, which is the purpose of the drug.
Scurvy, a disorder caused by vitamin C deficiency, can cause easy bruising. Scurvy occurs mainly in malnourished adults, particularly alcoholics. Vitamin C helps synthesize collagen, which makes up skin tissue, as well as blood vessels. Fragile blood vessels break easily, causing bleeding. Ingesting as little as 10 milligrams per day of vitamin C prevents scurvy, according to the Linus Pauling Institute. You can obtain adequate amounts of vitamin C from fruits and vegetables such as grapefruit, oranges, strawberries, sweet red peppers and broccoli.
Vitamin E helps the body use vitamin K and acts as an antioxidant in the body. Anti-oxidants reduce cell damage by attacking free radicals, molecules that can damage DNA in cells. However, high doses of vitamin E have more of a reputation as a blood thinner that causes bleeding, especially if you're already taking a blood thinner. Doses of vitamin E over 400 international units per day may increase the risk of bruising rather than decrease it. Ask your doctor before taking vitamin E to prevent or treat easy bruising.
If you or your child suddenly begins to bruise more than usual or if bruises appear without any apparent injury, see your doctor for blood tests to check for diseases associated with bruising, such as leukemia. Bruising in unusual areas, like the back, especially if accompanied by fever or swollen lymph nodes, requires immediate medical evaluation. While vitamins may help prevent bruising if you have a specific vitamin deficiency, taking extra vitamins won't help if you are already getting the right amount of nutrients.