Another angle on the multivitamin vs. preeclampsia debate

Although previous studies have found that taking vitamin supplements in early pregnancy doesn't seem to prevent preeclampsia, researchers have recently found that taking multi- or prenatal vitamins during the 6 months surrounding conception reduces the risk of preeclampsia by about 45%, according to data from the Pregnancy Exposures and Preeclampsia Prevention Study.

Almost 2,000 women at less than 16 weeks' gestation were classified as users or non-users of multivitamins or prenatal vitamins based on their report of usage during the previous 6 months. While the unadjusted prevalence of preeclampsia was 4.4% among nonusers and 3.8% among users, adjustment for race/ethnicity, marital status, parity, prepregnancy physical activity, and income produced a 45% reduction in risk among users (OR=0.55, 95% CI; 0.32–0.95). Those who took vitamins regularly and were lean prior to pregnancy enjoyed an even greater benefit: a 71% reduction in risk (OR=0.29, 95% CI; 0.12–0.65), while those who were overweight received no protective benefit.

Bodnar LM, Tang G, Ness RB, et al. Periconceptional multivitamin use reduces the risk of preeclampsia. Am J Epidemiol. 2006;164:470-477.