Gas liquid chromatography was used to examine the effect of treatment on the blood content of saturated and unsaturated fatty acids in 75 patients with coronary heart disease and essential hypertension. There were three groups of patients. The first group (30 subjects) received lipoic acid, whereas the second one (30 subjects) were given biotin nd pyridoxine. Fifteen patients (controls) did not receive any vitamins. Lipoic acid was found to raise the content of linoleic and arachidonic acids and to decrease the content of myristic acid. Meanwhile administration of biotin and pyridoxine led to an increase in the content of eicosatriene and arachidonic acids and to a reduction in the concentration of myristic and stearic acids. In the 15 patients who did not receive any vitamins, the blood content of fatty acids remained unchanged. Comparatively, the preference is given to lipoic acid that raises the blood content of linoleic acid playing an important part in the prophylaxis of atherosclerosis.