Daily multivitamin supplementation and vitamin blood levels in the elderly: a randomized, double-blind, placebo-controlled trial.

Despite the many questions being raised about multivitamin use by the elderly, it has not been proven that consuming an oral multivitamin alters vitamin blood levels in the aged. To address this question, we performed a randomized, prospective, placebo-controlled study of daily multivitamin supplementation in 101 noninstitutionalized ambulatory elderly persons (median age, 64 years). Vitamin levels were assayed at baseline, and at two and four months of supplementation. At four months, those taking multivitamins had statistically significant increased levels of water soluble vitamins (C, B2, B12, plasma, and erythrocyte folate) that were greater than changes noted for the placebo group. This was not true for fat soluble vitamins A and E. Greater storage pools of fat soluble vitamins help explain this discrepancy. We conclude that in the ambulatory elderly, oral multivitamins can raise levels of water soluble vitamins but the effect on fat soluble vitamins remains uncertain.