EFFECT OF ORAL PYRIDOXINE HYDROCHLORIDE SUPPLEMENTATION ON IN-VITRO PLATELET SENSITIVITY TO DIFFERENT AGONISTS

Effect of vitamin B-6 (pyridoxine-HCl, CAS 58-56-0) on platelet aggreg ation, plasma lipids and serum zinc level was investigated. The trial comprised 24 healthy male volunteers, aged between 19-24 years. The su bjects were randomized in two groups 12 and treated for 4 weeks by a s ingle daily oral dose of 5 mg/kg vitamin B-6 or placebo. Pyridoxine in hibited ADP- or epinephrine-induced aggregation by 48% and 41% (p < 0. 001), respectively, whereas there was no change in control group. No s ignificant effect on either, bleeding time, coagulation time or on pla telet count was demonstrated in subjects given placebo. Pyridoxine pro longed both bleeding and coagulation time but not over the physiologic al limits. It had no effect on platelet count. These observations stro ngly suggest that vitamin B-6, with no effect on platelet count, not o nly inhibits platelet aggregation but also prolongs clotting time. Pyr idoxine significantly reduced total plasma lipid and cholesterol level s, whereas it enhanced HDL-cholesterol level. Serum zinc level was als o significantly increased by pyridoxine (p < 0.001). These findings su ggest that oral vitamin B-6 inhibits platelet aggregation in normal su bjects.