Effect of Vitamin A administration on free radicals and lactate levels in individuals exercised to exhaustion

This study was performed to explore the effect of vitamin a administration on free radicals production and antioxidant system activity and lactate levels in individuals exercised to exhaustion the study registered 10 healthy sedentary males their mean age was 22,85±0,26 years. the subjects were orally administrated with 300 mg vitamin a (retinol) for 4 weeks and engaged in strenuous exercise (using the bruce protocol) once a week. blood samples were collected from the subjects at four different times,before and after the supplementation and before and after exercise to analyze malondialdehyde (mda),nitric oxide (no),glutathione (gsh),glutathione peroxidase (gsh-px),catalase (cat),superoxide dismutase (sod) levels using colorimetric elisa test kits and plasma lactate levels using an autoanalyzer. exhaustion exercise leaded to an increase in both mda,no,and lactate,and gsh,gsh-px,cat and sod levels compared to resting levels both before and after supplementation (p<0.05). increased no levels found in pre-supplementation exhaustion showed a significant decrease after the supplementation of vitamin a (p<0.05),but the other parameters were not changed after vitamin a administration. the results of our study demonstrate that the increase caused by 4-week strenuous exercise in the levels of the free radical no was offset by vitamin a supplementation. it can be suggested that supplementation of vitamin a at physiological doses has a limited effect on lipid peroxidation caused by strenuous exercise.