[Comparative study of the hemolytic action of group D vitamins].

Hemolytic effects of the vitamins of the D group (ergocalciferol - D2, cholecalciferol - D3, and 1 alpha-hydroxycholecalciferol - 1 alpha-OH-D3) were compared using rat erythrocytes. The latent period of hemolysis, caused by 1 alpha-OH-D3 was approximately 3-fold shorter as compared with the hemolysis caused by D2 or D3. Apparent values for energy of activation of hemolysis, estimated at 30-45 degrees, constituted for D2 - 23.2 kcal/mol, D3 - 25.3 kcal/mol, 1 alpha-OH-D3 - 13.1 kcal/mol. Despite the higher hemolytic activity, the rate of 1 alpha-ON-D3 autooxidation was distinctly lower than that of D3.