Margaret A.WinkerMDIndividualAuthorPhil B.FontanarosaMD, Senior EditorIndividualAuthor
In Reply.— As stated in our article, clinical trials of folate and vitamin B6 supplementation in the prevention of CHD are warranted to determine the independent effects of these 2 vitamins and to rule out confounding variables. However, we disagree with Drs Cleophas and van der Meulen that the inverse association we reported is likely due to other lifestyle factors. Controlling for use of vitamin E supplements and smoking status slightly attenuated the RR of CHD among women with the highest intakes of folate and vitamin B6, but accounting for other known cardiovascular risk factors (eg, physical activity, body weight) made little further difference. For factors such as job demand or psychosocial factors to attenuate further this RR, they would need to be strongly related to intake of folate and vitamin B6 and be strong predictors of CHD independent of other factors already accounted for in our analysis. This seems unlikely. Further, if self-selection of healthy individuals into the highest quintiles of intake were to explain our results, we would expect other micronutrients to be similarly related to CHD risk; we did not find inverse associations for vitamin C, thiamin, and riboflavin.
Rimm EB, Willett WC, Hu FB, Colditz GA, Sampson L, Manson JE, Hennekens CH, Stampfer MJ. Relationship of Dietary Folate and Vitamin B6 With Coronary Heart Disease in Women—Reply. JAMA. 1998;280(5):417-419. doi:10-1001/pubs.JAMA-ISSN-0098-7484-280-5-jbk0805