Chemical composition and characterstics of Vitamin C
The chemical structure of vitamin C is almost identical to that of glucose. All animals except humans,monkeys and guinea pigs can synthesize ascorbic acid from glucose.
Ascorbic acid exists in nature both as reduced and oxidised form calle ddehydroascorbic acid.Theses substances are in a state of reverse equilibrium in bioplogical sysytems and both have same bilological activity.
Ascorbic acid is
- an unstable, highly reducing,easily oxidisable acid
- can be destroyed by oxygen,alkalies and high temperature.
- oxidation is accerlated by heat,light,alkalies,oxidative enzymes and traces of copper and iron.
Digestion and absortion of Vitamin C
Being soluble in water,it is rapidly absorbed from the gastro-intestinal tract and distributed to the various tissues.
Functions of Vitamin C
- Intercellular cement substance – Vitamin C is required to buil and maintain bone matrix, cartilage, dentine, collagen, capillages and connective and general body tissue.
- General body metabolism – Tissues which are metabolically, more active such as the adrenal gland, brain, kidney, liver and pancreas, contain more Vitamin C. It is closely associated with protein in tissue growth,tissue growth,tissue building and rebuilding and in cell metabolic processes.
- Growth – Periods such as pregnancy, infancy and childhood demand more ascorbic acid.
- Building haemoglobin – It helps in the formation of haemoglobin and development of red blood cells by influencing the absorption of iron for haemoglobin formation.
- Fever and infecrtion – Resistance to infections is helped by optimum tissue stores of vitamin C.
- Healing of wounds including internal fractures of bones – Vitamin C is needed in large amounts for extensive tissue building such as in severe burns.
- Stress – Large amounts of ascorbic acid are required by adrenal tissue during any body stress.
- Metabolism of Tryosine – Vitamin c is necessary for the metabolism of tyrosine.
Deficiency symptoms of Vitamin C
- It results in defective formation of the intercellular cementing substance.
- Shooting joint pains, irritability, retardation of growth in an infant or child , anaemia, shortness of breath, poor wound healing, increased suspectibility to infections.
- Deficiency syndrome of Vitamin C scurvy. Diet deficient in in ascorbic acid especially in case of infants above 6 months leads to gross deficiency of vitamin C.
- In scurvy- There is pain, tenderness and swelling of the thighs and legs. The baby does not move and cries when handled. There is pallor and constant irritability. This may be accompanied by fever, infections and vomiting. Gums are likely to have swelling, tenderness and bleeding. Bones become brittle and cease to grow, and normal structures are replaced by connective tissue that contain cartilage.
- In adults, scurvy is manisfested as black and blue spots on the skin, swelling, infection and bleeding of gums and anaemia. Even a slight injury causes bleeding.