British Scientist Says Daily Multivitamins Generally Unnecessary

LONDON--Regularly taking a vitamin supplement is only beneficial in some cases, according to David A. Bender, a senior lecturer in biochemistry at University College London, who published an editorial in the July 27 British Medical Journal (325, 7357:173-4, 2002) (bmj.com). While 20 percent to 30 percent of the population in developed countries takes a daily multivitamin, it may not be doing any good since deficiency is not a problem in most countries, according to Bender. The question now, he wrote, is whether higher levels of intake provide added benefits. Bender said no "satisfactory answers" to this question have been provided by biomarkers of optimum nutritional status, rather than the absence of deficiency, or by epidemiological studies followed by intervention studies.

Bender cited epidemiological evidence that high plasma levels of vitamin E reduce the risk of non-fatal, but not fatal, myocardial infarction. "While the benefits from reducing non-fatal infarctions are obvious, this is hardly convincing evidence of the benefits of vitamin E supplementation," he said.

Bender noted that while there is evidence that high intakes of beta-carotene are associated with lower incidence of cancers, the benefit may simply be due to fruit and vegetable consumption. Similarly, he claimed that while vitamin C is linked with reducing cancer incidence, fruits and vegetables are rich sources of the vitamin, as well as other compounds, that may be protective against cancer.

The two vitamins that Bender cited as having a benefit were vitamin D and folic acid. Vitamin D, he said, delays bone loss, making supplements useful with increasing age. Folic acid's ability to prevent neural tube defects has "been shown convincingly," Bender said, indicating periconceptional folic acid supplementation is beneficial.

"The answer to the question of whether we should take a multivitamin tablet every day must be that unless our intake is inadequate as a result of a poor diet, then supplements will probably do us no good," Bender concluded.