Effects of vitamin B12 on cadmium toxicity in rats.

The survival rate was high among male Sprague rats treated with 0.15 mg/kg vitamin B12 (cyanocobalamine) after injection of 5 mg/kg CdCl2.H2O (LD50). The cadmium content of the liver and, for some protocols, in the kidney was significantly reduced in survivors. According to UV-V and multinuclear (1H, 13C, 31P, and 113Cd) magnetic resonance spectroscopy no direct interaction seems to take place between cyanocobalamine and CdCl2 in aqueous solution at pH 4.5. An indirect mechanism is put forward to explain the antidotal activity.