Vitamin B6 status and its relationship with polyunsaturated fatty acid concentrations during pregnancy

Abstract

RationaleSuboptimal vitamin B6 status was shown to alter polyunsaturated fatty acid (PUFA) profiles, decreasing plasma (n‐3) and (n‐6) PUFA concentrations, in healthy men and women.AimTo assess the relationships between plasma pyridoxal 5'‐phosphate (PLP) and docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and arachidonic acid (AA) concentrations at different stages of pregnancy.MethodsProspective cohort study in 213 healthy pregnant women (aged 20‐40 y) followed across trimesters at 5‐13, 20‐26 and 30‐36 wk. The study was conducted in Rio de Janeiro, Brazil. Fasting plasma PLP (nmol/L) and serum PUFA (µg/mL) were measured by HPLC and GLC, respectively.ResultsPlasma PLP concentrations [median (IQR)] dropped from 35.8 (28.4‐43.6) in the 1st to 21.2 (16.2‐27.1) in the 2nd trimester (P<0.0001) and further decreased to 16.9 (12.8‐21.6) in the 3rd trimester (P<0.0001). Median (IQR) PUFA concentrations were 55.8 (44.0‐65.5), 70.7 (60.9‐84.7), 74.5 (63.6‐89.6) for DHA; 8.4 (6.6‐11.7), 8.4 (6.5‐12.0), 7.4 (5.2‐10.9) for EPA; and 206 (179‐245), 236 (205‐270), 237 (207‐279) for AA in the 1st, 2nd, and 3rd trimester, respectively. Plasma PLP and DHA were correlated (P<0.05) in the 1st (ρ=0.14) and 2nd trimester (ρ=0.20); plasma PLP and EPA (ρ=0.24) and AA (ρ=0.18) were correlated in the 2nd trimester (P<0.05); no significant correlations were observed between PLP and any PUFA in the 3rd trimester.ConclusionsPlasma PLP concentrations were correlated with DHA, EPA and AA in early pregnancy.Funding: CNPq, FAPERJ, VRF‐FNH‐UBC