Description

vitamin C, the water-soluble vitamin, is readily absorbed from the gastrointestinal tract and is widely distributed in the body tissues. It is believed to be involved in biological oxidations and reductions used in cellular respiration. It is essential for the synthesis of collagen and intracellular material. Vitamin C deficiency develops when the dietary intake is inadequate and when increased demand is not fulfilled. Deficiency leads to the development of well defined syndrome known as scurvy, which is characterized by capillary fragility, bleeding (especially from small blood vessels and the gums), anaemia, cartilage and bone lesions and slow healing of wounds.

Vitamin C is indicated for prevention and treatment of scurvy. It may be indicated in pregnancy, lactation, infection, trauma, burns, cold exposure, following surgery, fever, stress, peptic ulcer, cancer, methaemoglobinaemia and in infants receiving unfortified formulas. It is also prescribed for haematuria, dental caries, pyorrhea, acne, infertility, atherosclerosis, fractures, leg ulcers, hay fever, vascular thrombosis prevention, levodopa toxicity, succinyl-choline toxicity, arsenic toxicity etc. To reduce the risk of stroke in the elderly, long-term supplementation with Vitamin C is essential.

Potentially hazardous interactions: Ascorbic acid is incompatible in solution with aminophylline, bleomycin, erythromycin, lactobionate, nafcillin, nitrofurantoin sodium, conjugated oestrogen, sodium bicarbonate, sulphafurazole diethanolamine, chloramphenicol sodium succinate, chlorthiazide sodium and hydrocortisone sodium succinate. Useful interactions: Ascorbic acid increases the apparent half-life of paracetamol and enhances iron absorption from the gastrointestinal tract.

Vitamin C has little toxicity and only mega-doses of vitamin C may cause diarrhoea, abdominal bloating, iron over-absorption that is harmful in patients with thalassaemia, sideroblastic anemia, and haemochromatosis; hyperoxaluria, hyperuricosuria, and hemolysis in patients with glucose-6 phosphate dehydrogenase deficiency. A pregnant woman taking more than 5 gm/day may suffer fetal abortion.

The drug is safe in normal doses in pregnant women, but a daily intake of 5 gm or more is reported to have caused abortion. The drug may be taken safely during lactation.

Ingestion of megadose (more than 1000 mg daily) of vitamin C during pregnancy has resulted in scurvy in neonates. Vitamin C in mega-doses has been contraindicated for patients with hyperoxaluria. Vitamin C itself is a reactive substance in the redox system and can give rise to false positive reactions in certain analytical tests for glucose, uric acid, creatine and occult blood.

Vitamin-C Preparations

Should be stored in a dry place below 30˚C.