Marginal Vitamin B-6 Deficiency Decreases Plasma (n-3) and (n-6) PUFA Concentrations in Healthy Men and Women

Previous animal studies showed that severe vitamin 8-6 deficiency altered fatty acid profiles of tissue lipids, often with an increase of linoleic acid and a decrease of arachidonic acid. However, little is known about the extent to which vitamin B-6 deficiency affects human fatty acid profiles. The aim of this study was to determine the effects of marginal vitamin B-6 deficiency on fatty acid profiles in plasma, erythrocytes, and peripheral blood mononuclear cells (PBMC) of healthy adults fed a 28-d, low-vitamin 8-6 diet. Healthy participants (n = 23) received a 2-d, controlled, vitamin 8-6 adequate diet followed by a 28-d, vitamin B-6 restricted diet to induce a marginal deficiency. Plasma HDL and LDL cholesterol concentrations, FFA concentrations, and erythrocyte and PBMC membrane fatty acid compositions did not significantly change from baseline after the 28-d restriction. Plasma total arachidonic acid, EPA, and DHA concentrations decreased from (mean +/- SD) 548 +/- 96 to 490 +/- 94 mu mol/L, 37 +/- 13 to 32 +/- 13 mu mol/L, and 121 +/- 28 to 109 +/- 28 mu mol/L positive false discovery rate (pFDR) adjusted P < 0.051, respectively. The total (n-6):(n-3) PUFA ratio in plasma exhibited a minor increase from 15.4 +/- 2.8 to 16.6 +/- 3.1 (pFDR adjusted P < 0.05). These data indicate that short-term vitamin 8-6 restriction decreases plasma (n-3) and (n-6) PUFA concentrations and tends to increase the plasma (n-6):(n-3) PUPA ratio. Such changes in blood lipids may be associated with the elevated risk of cardiovascular disease in vitamin B-6 insufficiency. J. Nutr. 142: 1791-1797, 2012.