Folate status during pregnancy in women is improved by long-term high vegetable intake compared with the average western diet.

The effect of increasing dietary folate on folate status during pregnancy is controversial. The aim of this study was to compare folate intake and folate status during pregnancy of women with high long-term vegetable intake and those eating an average Western diet. In a prospective study that included 109 participants, pregnant women adhering to a predominant vegetarian diet with high vegetable intake for 8 +/- 0.5 y with subgroups of ovo-lacto vegetarians (n = 27) and low meat eaters (n = 43) and women eating an average Western diet (control group, n = 39) were compared with regard to dietary intake and plasma and red blood cell (RBC) folate concentrations during wk 9-12, 20-22 and 36-38 of gestation. Plasma and RBC folate concentrations were highest in ovo-lacto vegetarians, followed by low meat eaters and lowest in the controls. Ovo-lacto vegetarians and low meat eaters showed a lower risk for folate deficiency, with RBC folate concentrations of <320 nmol/L resulting in odds ratios of 0.10 (95% confidence interval, 0.01-0.56) and 0.52 (95% confidence interval, 0.20-1.34), respectively. In ovo-lacto vegetarians, the RBC folate concentration was positively related to the intake of vitamin B-12 (r = 0.51, P: < 0.0001). The results of the study suggest that long-term high vegetable intake favorably affects plasma folate as well as RBC folate concentrations throughout pregnancy and reduces the risk of folate deficiency if an adequate vitamin B-12 supply is ensured.