Madam, - David Carroll (March 20th) rounds on me regarding my Science Todaycolumn of March 15th on vitamin supplements. I wonder if his reading of my article went beyond scanning its title, because he makes no reference to my central point. This was my report of a large-scale scientific analysis of the effects of taking antioxidant vitamin supplements - beta carotene and Vitamins A, C and E - on all-cause deaths of adults in prevention trials, just published in the Journal of the American Medical Association.
The study found that beta carotene, Vitamin A and Vitamin E were associated with 7 per cent, 16 per cent and 4 per cent increased risk of mortality respectively. No increased mortality risk was seen with Vitamin C, but there was no evidence that Vitamin C increases longevity. These results contradict reports that antioxidant vitamin supplements improve health.
The authors comment: "Considering that 10 to 20 per cent of the North American and European population (80-160 million) consume the assessed supplements, the public health consequences may be substantial".
Mr Carroll lists several medical conditions that may be ameliorated by vitamin supplements, e.g. pernicious anaemia and osteoporosis. I have no problem with the vitamin treatment of specific conditions under medical advice, as I made clear. What I do caution against is the widespread taking, particularly of antioxidants, in liberal amounts. In many houses, bottles of vitamin pills sit on the kitchen table like salt and pepper canisters. - Yours, etc,
Prof WILLIAM REVILLE, Biochemistry Department, University College, Cork.