Abstract
In the previous papers, the authors reported concerning the occurrence and isolation of water-soluble vitamin D-sulfate in fresh mammalian milk. Afterwards, further researches were repeated for the physiological activities of the compound using pure synthetic vitamin D-sulfate in water-soluble form. At start of experiments, toxicity of vitamin D_2-sulfate in saline solution upon mice was tested intraperitoneally by the ordinary method. The lethal doses on mice (LD_<50>) were estimated to be about 2,500,000 I.U./kg. In the second experiment, studies were promoted for antirachitic ability of water-soluble vitamin D-sulfate using the Steenbock's diet, and it was found that the prophylactic dosing of the water-soluble vitamin D-sulfate may be the same to that of free vitamin D. Finally, experiments were carried out to elucidate whether there may be any appearance of hypervitaminosis after administration of water-soluble vitamin D-sulfate in large dosage. No toxic symptom was recognized even when supplemented with 5,000 I.U. of the compound per os.
