Ethics of a Randomized Trial of Periconceptual Vitamins

To the Editor.—  Dr Holmes¹ offers a number of thoughtful and cogent remarks concerning the report on periconceptual use of multivitamins by Mulinare et al.² However, one comment he makes raises an important ethical issue that is worthy of further comment.Dr Holmes observes that it is fortunate that "a larger, randomized trial of the effectiveness of periconceptual vitamin supplements is under way in Great Britain at this time." This study will, Dr Holmes suggests, help answer some of the questions that remain concerning the advisability of taking vitamin supplements to prevent anencephaly and other neural tube defects. With the exception of the ongoing British study, there has not been a definitive randomized trial of the prophylactic efficacy of vitamin supplements for neural tube disorders.The issue of whether it is ethically desirable to conduct a large, randomized trial to assess the prophylactic efficacy of vitamins is one