Sir, Kathryn Holmquist's warning (September 4th) that healthy people who take vitamin, supplements casually may be putting their health at risk is true but there is an important role for vitamin supplementation. It is true that an American study testing the efficacy of Beta Carotene and Vitamin A in patients at high risk of lung cancer had to be stopped 21 months earlier than planned, because of an increase in the incidence of lung cancer and risk of death from cardiovascular disease and any cause in the supplemented patients.
In another study of 22,071 male doctors, half of whom took Beta Carotene on alternate days for 12 years, and half of whom took placebo, no harm or benefit was found with regard to malignant disease, cardiovascular death or death from all causes. Both studies were published in May of this year in the New England Journal of Medicine. However, it is wise to conclude that taking Beta Carotene supplements is not a good idea.
Earlier in 1994, a study involving 29,133 male smokers from Finland found that mortality was eight per cent higher in those who received Beta Carotene, due to a higher incidence of lung cancer and heart disease. No apparent effect on total mortality was found in those who received vitamin E, but more deaths from stroke were observed in this group. On the other hand, there were fewer deaths from prostate cancer in the Vitamin E group over the 5-8 years of the study.
Vitamin E supplementation has been shown in the Cambridge Heart Antioxidant Study 1996 to reduce the risk of a non-fatal heart attack in patients with heart disease, but there was an excess in cardiovascular death which did not reach statistical significance. In 1993, studies had shown that the risk of coronary disease in men and in women had substantially reduced by taking Vitamin E supplements. Vitamin C seems to have no effect in heart disease.
Periconceptual folate supplementation, vitamin D, and calcium supplemental ion in elderly women, and vitamin and mineral supplementation, again in the elderly, have been shown to have a positive health benefit. Again, vitamin D and calcium may be dangerous in certain circumstances 14p to date, professional advice should be sought before self dosing with "good vitamins". Beta Carotene should be removed from over the counter sales in chemist shops. Yours, etc., Glasnevin Avenue Dublin 11.