The Reuters report (May 19) on the UK's Food Standard Agency recommendation to fortify flour with folic acid to reduce birth defects, is only part of the story. That folic acid supplementation reduces risk of birth defects is old hat. What is not so widely known is that medical science has been interested, for well over a decade, as to whether folic acid supplementation might reduce heart disease and strokes in adults.

It is estimated that in most population groups, about a third have low blood folate associated with raised blood homocysteine levels. The latter damages blood vessels and may contribute to the overall risks for heart attacks and strokes. Folic acid supplementation reduces blood homocysteine, and may therefore reduce cardiovascular disease risks, although this is as yet unproven. American health authorities have not only made adding folic acid to flour compulsory over a decade ago, but also recommend a multivitamin and multimineral tablet daily (they usually contain folic acid).

Although use of vitamin/mineral/antioxidant supplements remains controversial, the American College of Physicians recommends them particularly for young women, the elderly and those with suboptimal nutrition, such as people on very strict slimming diets. They should obviously be used to supplement, not to substitute, a diet rich in vegetables, fruits and other vitamin-rich foods.