Bruising can result from a variety of causes. "The Merck Manual of Diagnosis and Therapy" describes a common and benign condition called purpura simplex, in which bruises appear over your thighs, buttocks and upper arms in the absence of known trauma. Elderly individuals also develop harmless bruising as a result of sun-related aging of their skin. However, bruising due to malnutrition or abnormalities in your platelets, blood vessels or clotting factors might require medical attention. Vitamin C deficiency is a rare cause of bruising in developed countries. If you seem to bruise easily, see your doctor for an evaluation.
Vitamin C Functions
Vitamin C, or ascorbic acid, is a water-soluble vitamin that is essential for your health. Although most mammals can synthesize vitamin C in their cells, humans do not possess the metabolic machinery to manufacture this nutrient and must obtain it from their food. Vitamin C is an important antioxidant and immune stimulant, but one of its most critical functions is to act as a cofactor for the enzymes that convert the amino acids proline and lysine prior to their incorporation into collagen.
Tissue Integrity
Collagen is the most abundant protein in your body. Dr. Elson Haas, author of "Staying Healthy with Nutrition," reports that collagen forms the scaffolding for your muscles, skin, eyes, bones and internal organs. Although collagen takes slightly different forms in different tissues, its initial synthesis involves the formation of a coiled molecule that requires vitamin C-dependent enzymes. Vitamin C deficiency leads to a condition called scurvy, which is characterized by poor collagen integrity, mucous membrane breakdown, blood vessel fragility, bruisability and bleeding.
Dosing
Since vitamin C is a water soluble vitamin, excess dietary intake is readily eliminated through your urine. Recommended dietary allowances -- the doses required to prevent scurvy -- vary from 40 mg daily for infants to 120 mg daily for breastfeeding women. If you smoke, increase your daily dose by 25 mg. The National Academy of Sciences has established a tolerable upper intake level of 2,000 mg daily for adults. However, the Linus Pauling Institute at Oregon State University states that doses of 10 g and more have been used for treating certain conditions, such as cancer.
Considerations
The amount of vitamin C you need for optimal health may be higher than the doses recommended by the National Academy of Sciences. Although the recommended dietary allowances will prevent scurvy, you might require higher doses to prevent bruising, depending on your age, stress levels, underlying medical conditions and other factors. High-dose vitamin C can cause nausea and diarrhea, but these side effects can be minimized by starting at a low dose -- 100 mg to 250 mg daily -- and gradually increasing your intake. Ask your doctor if you need additional vitamin C.
References
- "The Merck Manual of Diagnosis and Therapy, 18th Edition: Bleeding Due to Abnormal Blood Vessels"; Mark H. Beers, M.D., Editor-in-Chief; 2006
- "Staying Healthy with Nutrition: Proteins"; Elson M. Haas, M.D.; 2006
- Linus Pauling Institute at Oregon State University: Vitamin C
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