Water-soluble vitamins' effects are shown on Table 1.З.1.1.
In particular, it can be shown that vitamin C acts as an antioxidant, and under oxidative stress conditions it helps protect tissues from damages due to free radicals. The principal role is associated with a proper maintenance of the normal functions of the immune system; it is a cofactor of eight different enzymes and it participates in the biosynthesis of collagen, carnitine, adrenalin, and noradrenalin and in tyrosine metabolism. Moreover, it helps in the detoxification of nitrous composites and in the assimilation of iron. It also reduces age-related macular degeneration (AMD) and loss of vision.
Vitamin C deficiency causes poor bone mineralization (ensuing of low collagen production), weakness, fatigue, anorexia, and an increased susceptibility to infections; it also worsens the negative effects associated to a lack of iron. Milk vitamin C content is low, which is why this food is often supplemented with ascorbic acid or sodium ascorbate, which also ensures other micronutrients' stability (e.g., vitamin A and vitamin E) or improves their absorption (e.g., iron). Since vitamin C is highly sensitive to oxygen or high temperatures, it has to be overdosed and/or used in encapsulated forms such as liposomes.