Vitamin C is water-soluble, and probably the most famous of all the vitamins. Even before its discovery in 1932, physicians recognised that there must be a compound in citrus fruits preventing scurvy, a disease that killed as many as 2 million sailors between 1500 and 1800. Later researchers discovered that man, other primates and the guinea pig depend on external sources to cover their Vitamin C requirements. Most other animals are able to synthesise Vitamin C from glucose and galactose in their body. The most prominent role of Vitamin C is its immune stimulating effect, which is important for the defence against infections such as common colds. It also acts as an inhibitor of histamine, a compound that is released during allergic reactions. As a powerful antioxidant it can neutralise harmful free radicals and aids in neutralising pollutants and toxins. Thus it is able to prevent the formation of potentially carcinogenic nitrosamines in the stomach (due to consumption of nitrite-containing foods, such as smoked meat). Importantly, Vitamin C is also able to regenerate other antioxidants such as Vitamin E. Vitamin C is required for the synthesis of collagen, the intercellular 'cement' substance which gives structure to muscles, vascular tissues, bones, tendons and ligaments. Due to these functions Vitamin C, especially in combination with zinc, is important for the healing of wounds. Vitamin C contributes to the health of teeth and gums, preventing haemorrhaging and bleeding. It also improves the absorption of iron from the diet, and is needed for the metabolism of bile acids, which may have implications for blood cholesterol levels and gallstones. In addition, Vitamin C plays an important role in the synthesis of several important peptide hormones and neurotransmitters and carnitine. Finally, Vitamin C is also a crucial factor in the eye's ability to deal with oxidative stress, and can delay the progression of advanced age-related macular degeneration (AMD) and vision-loss in combination with other antioxidant vitamins and zinc.

El-Meghawry El-Kenawy A, Osman HE, Daghestani MH. The effect of Vitamin C administration on monosodium induced liver injury. An experimental study. 1. Exp Toxicol Pathol. 2012 Jun 1. [Epub ahead of print]

Monosodium glutamate (MSG) is a commonly used food enhancer. Glutamate is used as food additive for enhancing the "meat flavor" of food and gives a particular taste named "umami". In this study, we evaluated the effect of Vitamin C on monosodium glutamate induced rat liver injury. This study was divided into 3 groups: group 1 received a diet containing 0.9% NaCl; group 2 received diet containing MSG 6mg/g/b.w.; and group 3 received a diet containing 6mg/g/b.w. followed by Vitamin C (500mg/kg/b.w.) for 45 days. The resulting changes were detected using histological, histochemical, ultrastructural, and immuohistochemical analysis. Severe alterations were recorded including dilatations of the central veins; severe cyto-architectural distortions of the hepatocytes; marked reduction in both carbohydrates and proteins; vacuolated cytoplasm, swollen mitochondria and vesiculated rough endoplasmic reticulum with picknotic nuclei; in addition to significant variation in the expression of ki-67 and p53 proteins. The data obtained from this study showed the improvements in the pathological architecture of the liver after treatment with Vitamin C. The present data point to the ameliorative effect of Vitamin C against MSG induced liver injury.