Supplementation with omega-3 fatty acids during gestation and lactation to a vitamin B12-deficient or -supplemented diet improves pregnancy outcome and metabolic variables in Wistar rats.

Maternal vitamin B-12 deficiency leads to an adverse pregnancy outcome and increases the risk for developing diabetes and metabolic syndrome in mothers in later life. Our earlier studies have demonstrated that vitamin B-12 and n-3 polyunsaturated fatty acids (PUFA) are interlinked in the one carbon cycle. The present study for the first time examines the effect of maternal n-3 PUFA supplementation to vitamin B-12 deficient or supplemented diets on pregnancy outcome, fatty-acid status and metabolic variables in Wistar rats. Pregnant dams were assigned to one of the following groups: control, vitaminB(12) deficient, vitaminB(12) supplemented, vitaminB(12) deficient+n-3 PUFA or vitaminB(12) supplemented+ n-3 PUFA. The amount of vitamin B-12 in the supplemented group was 0.50 mu g kg(-1) diet and n-3 PUFA was alpha linolenic acid (ALA) 1.68, eicosapentaenoic acid 5.64, docosahexaenoic acid (DHA) 3.15 (g per 100 g fatty acids per kg diet). Our findings indicate that maternal vitamin B-12 supplementation did not affect the weight gain of dams during pregnancy but reduced litter size and weight and was ameliorated by n-3 PUFA supplementation. Vitamin B-12 deficiency or supplementation resulted in a low percentage distribution of plasma arachidonic acid and DHA. n-3 PUFA supplementation to these diets improved the fatty-acid status. Vitamin B-12 deficiency resulted in higher homocysteine and insulin levels, which were normalised by supplementation with either vitamin B-12 or n-3 PUFA. Our study suggests that maternal vitamin B-12 status is critical in determining pregnancy outcome and metabolic variables in dams and that supplementation with n-3 PUFA is beneficial.