Roles of Vitamin C

Vitamin C has many other names including L-Ascorbic acid, L-xyloascorbic acid, 3-oxo-L-gulofuranolactone, L-3-ketothreohexuronic acid lactone, antisorbutic vitamin, ascorbic acid and ascorbate. It is a water soluble vitamin which synthesized from glucose by many animals. In some mammals, it is synthesized in liver while birds and reptiles, it is synthesized in kidney. However, human and several species are unable to synthesize vitamin C. Insufficient vitamin C in diet can cause scurvy and lack of enzymatic functions.

Vitamin C is important in forming collagen for structure of bones, cartilage, muscle and blood vessel.  It plays a role in collagen gene expression, secretion of cellular procollagen and involves in biosynthesis of connective tissue components including elastin, fibronectin, proteoglycans and bone matrix. The symptoms of deterioration of elastic tissue can be seen among people with scurvy.

Vitamin C is a reducing agent and acts as an antioxidant. It helps preventing the damaging effects of free radicals. Vitamin C has the ability to donate it’s electron to unbalance molecules or compounds. Most of the time, it protects against oxidative damage in eyes, neutrophils and semen.  It also protects against plasma and low-density lipoprotein (LDL) oxidation and helps regenerating vitamin E. In previous study, vitamin C also indirectly helps the regeneration of glutathione and alpha-tocopherol to active form. This special effect of vitamin C reduces the occurrence of cancers.

Vitamin C helps to increase the absorption of non-heme iron. Non-heme iron can be found mainly in cereals, beans and dark green vegetables. The iron from these sources are poorly absorbed which causes most vegetarians have difficulty to get sufficient iron in their diet. However, vitamin C can be eaten with non-heme iron in order to increase the absorption. Vitamin C also protects the folic acid reductase, the enzyme needed to convert folic acid to folinic acid.

The concentration of vitamin C in gastric juice may prevent the formation of N-nitroso compounds, the element that can cause mutagenic and lead to cancer. The high intake of vitamin C can reduce the risk of gastric cancer. Vitamin C is one of the safest nutrients. Some medical officers prescribe vitamin C for patients with common cold. It may not cure the common cold, but vitamin C may enhance the effectiveness of immune system. There are many benefits of vitamin C. What people need to do is to include vitamin C in their diet. 

References:

Recommended Nutrient Intakes for Malaysia (RNI), Ministry of Health Malaysia. (2005)

Vitamin C – National Agricultural Library, USDA (United State Department of Agriculture)