Phosphorylation of Vitamin D₂, and the Action of the Phosphorylated Compound on Alkaline Kidney Phosphatase

Abstract

IN rickets, an increase in alkaline serum phosphatase may be found before any other symptoms have appeared. Administration of vitamin D restores the phosphatase value to its normal level. It is possible that, when there is a deficiency of vitamin D, an abnormally large amount of alkaline phosphatase is required¹. Cohn and Greenberg² have put forward the hypothesis that vitamin D facilitates the transition from organic to inorganic phosphate compounds and can thus influence ossification. Robison's³ investigations indicate that alkaline phosphatase is necessary for ossification. Hence it seems possible that there is some connexion between the mode of action of vitamin D and that of alkaline phosphatase. Vitamin D₂ can be obtained by phosphorylation in such a form that it is possible to dissolve it in water and thus test its influence on enzymatic reactions.