Vitamin C, or ascorbic acid, is an essential nutrient that operates in many different systems in the body. The body cannot produce vitamin C on its own, so it must be consumed in food or supplements. As a water-soluble vitamin, ascorbic acid doesn't stay in the body for long periods of time before being excreted in the urine.
Function
Vitamin C works in the body to assist in the building of L-carnitine, norepinephrine and collagen. This nutrient also stimulates the production and function of immune cells. It also may help prevent cardiovascular disease, stroke, cancer, gout and cataracts. Adequate vitamin C intake may help prevent toxicity in individuals exposed to lead. The highest levels of vitamin C in the body settle in the eyes, adrenal glands, pituitary gland, white blood cells and the brain.
Sources
Vitamin C can be found in whole and fortified foods, including citrus fruits, orange juice, strawberries, tomatoes, broccoli, parsley, bell pepper, papaya, kale and Brussels sprouts. Supplemental vitamin C comes in many forms, including straight ascorbic acid and buffered forms that are bound to minerals such as sodium or calcium. These variants tend to be less irritating to the digestive tract, as they are less acidic. Other forms are bound to vitamin C metabolites that are believed to help increase the bioavailability of the vitamin.
Deficiency
A vitamin C deficiency may show up as a reduction in immune function, dry hair, gum disease, nosebleeds, swollen joints, bruising and slow wound healing. When vitamin C levels in the body fall below about 300 mg, a condition called scurvy can develop. Scurvy is characterized by severe gum disease, loose teeth, skin bleeding, weakness and anemia.
Considerations
Vitamin C may react with some medications, including chemotherapy drugs and statins, when taken along with antioxidant supplements. While the upper limit of vitamin C consumption has been set by the Food and Nutrition Board of the U.S. Institute of Medicine at 2,000 mg per day, some doctors and scientists support the use of megadoses of vitamin C for preventing colds. The evidence supporting this use of vitamin C has been contradictory, and more studies are needed, explains the Linus Pauling Institute at Oregon State University.
Recommendations
The National Institutes of Health Office of Dietary Supplements recommends that vitamin C needs be met primarily through foods. The vitamin C in foods is easily lost during cooking and processing, so raw foods are the best source of this nutrient. According to the website World's Healthiest Foods, up to 25 percent of vitamin C in vegetables is lost during rapid blanching or after freezing and thawing of the food.
Member Comments