Vitamin C, or ascorbic acid, is an essential nutrient for humans and other animals. It is a cofactor in several enzymatic reactions including production of collagen.
Vitamin C is a strong antioxidant, as it easily releases electrons and therefore neutralizes free radicals.
Vitamin C is produced internally in almost all mammals. The exemptions are (1) most bats (2) guinea pigs and capybaras, (3) higher primates (apes) and (4) humans. With the exemption of humans are the others vegetarians by nature.
Humans must eat food that contains certain amounts of vitamin C to maintain their health. Recommended daily intake of vitamin C is 80-90 mg per day. Examples of food with high vitamin C levels are rose hip, chili pepper, guava, blackcurrant, kiwi, broccoli, loganberry, lychee, papaya, strawberry, orange and lemon.
Vitamin C occurs in high concentrations in immune cells and is consumed quickly during infections. Scientists do not exactly know what role vitamin C has in the immune system, but it is suggested that vitamin C modulates the activities of phagocytes and production of cytokines and lymphocytes. It is observed that animals that naturally produces their own vitamin C, rapidly increase their vitamin C levels during stress, for example when having an infection.
Vitamin C can be stored in the body for some weeks. Lack of vitamin C results in scurvy, a lethal condition that causes blood vessels to became brittle and rupture. Bleeding from the gums may be an indication of low vitamin C level.
Research suggests that low intake of vitamin C increase the risk for stroke. In 1953 did the Canadian doctor Willis report that vitamin C deficiency was identified as sole cause of atherosclerosis in laboratory animals. The reason was that vitamin C deficiency resulted in increased production of cholesterol to repair damaged blood vessels. It was later proved that high vitamin C levels reduced cholesterol levels. In 2011 did doctor Levy in USA report that vitamin C deficiency is the solitary root cause to all coronary arterial blockages.