1. The distribution of vitamin D sulfate in animal tissues was studied. Considerable amounts of the sulfate were formed in the liver, but extremely poor in other tissues.
2. Vitamin D-sulfokinase was isolated from rat-liver homogenate, and the optimum conditions were investigated.
3. Isotopic investigation for the biogenesis of vitamin D sulfate was carried out using the vitamin D-sulfokinase preparation.
The activity of the vitamin D2-sulfokinase preparation obtained by the authors was estimated to be 3.3% as estimated from the yield of vitamin D2 sulfate from the vitamin D2 employed.
THE VITAMIN SOCIETY OF JAPAN