Objective: To study associations between maternal dietary and supplement intake of antioxidants vitamin E, retinol and congenital heart defects (CHDs).
Design: Case-control study.
Setting: Erasmus MC, University Medical Center Rotterdam, the Netherlands.
Population: Participants were 276 case mothers of a child with CHD and 324 control mothers with their children.
Methods: Food frequency questionnaires covering the intake of the previous 4 weeks were filled out at 16 months after the index pregnancy. Data were compared between cases and controls using the Mann-Whitney U test. Risk estimates for the association between CHD and dietary intake of vitamin E and retinol were estimated in a multivariable logistic regression model.
Main outcome measures: Medians (5-95th percentile) and odds ratios with 95% CI.
Results: Dietary vitamin E intake was higher in case mothers than in controls, 13.3 (8.1-20.4) and 12.6 (8.5-19.8) mg/day (P= 0.05). CHD risk increased with rising dietary vitamin E intakes (P-trend = 0.01). Periconception use of vitamin E supplements in addition to a high dietary vitamin E intake above 14.9 mg/day up to nine-fold increased CHD risk. Retinol intakes were not significantly different between the groups and not associated with CHD risk.
Conclusions: High maternal vitamin E by diet and supplements is associated with an increased risk of CHD offspring.