132 страниц. 2012 год. LAP Lambert Academic Publishing Intake of vitamin B12 for three consecutive weeks had no effect on the weight or body shape of the mice. Also, no toxic effects were observed during the experiment. Intake of vitamin B12 (0.8 mg / kg body weight) before irradiation improved the mortality rate, when compared to the untreated irradiated group and the best improvement was observed at day 14 after irradiation. Intake of vitamin B12 prior to irradiation improved the rate of mitotic index. The best recoveries in mitotic index rate were at 6 and 72 hr after irradiation. Treatment with vitamin B12 prior to irradiation increased the total number of polychromatic erythrocytes (PCEs) by 17 % and decreased the total incidence of normochromatic erythrocytes (NCEs) by 4 folds. Intake of vitamin B12 prior to irradiation revealed a highly significant decrease in the morphological deformation of sperm head and tail by 1.4 folds.