Comparison between Crystalline Dihydrotachysterol and Calciferol in Patients Requiring Pharmacologic Vitamin D Therapy

Abstract

PATIENTS requiring pharmacologic amounts of vitamin D have usually been treated with ergocalciferol (vitamin D₂) although cholecalciferol (vitamin D₃) and dihydrotachysterol have also been used. Dihydrotachysterol, like ergocalciferol, is a product of irradiation of ergosterol and was isolated by Holtz and Schreiber,¹ who were searching for a steroid more effective than ergocalciferol in the treatment of hypocalcemic states. The pharmaceutical preparation AT₁₀ (Hytakerol), although assayed in terms of assumed dihydrotachysterol content, is actually a mixture of steroids with dihydrovitamin D₂II, an isomer of dihydrotachysterol, as the chief component.² This preparation has been shown . . .