Effect of Desoxypyridoxine-Induced Vitamin B6 Deficiency on Polyunsaturated Fatty Acid Metabolism in Human Beings

Abstract

The polyunsaturated fatty acids and major lipid components of the plasma and red blood cells were measured in a group of seventeen chronically ill human subjects before, during and after the induction of vitamin B₆ deficiency by the oral administration of a metabolic antagonist, desoxypyridoxine. All the subjects exhibited biochemical evidence of vitamin B₆ deficiency, and clinical evidence of such a deficiency developed in a majority of them. During the deficiency period the mean values of the red blood cell tetraenoic fatty acids decreased while the total phospholipids and cholesterol increased. Associated with this was a tendency for red blood cell trienoic acid levels to rise. Similar changes in the plasma were present but less striking. These results directly implicate vitamin B₆ in human fatty acid metabolism for the first time and are similar to those reported in some experiments with laboratory animals. Although our studies do not indicate the site of action of vitamin B₆ in fat metabolism, they are consistent, with its role in the conversion of linoleic acid to arachidonic acid. The cause of the slight hypercholesterolemic effect of pyridoxine deficiency is unknown