THE MANAGEMENT OF H Y POP A R ATH YRO ID ISM WITH lα‐HYDROXYVITAMIN D₃

A retrospective study of the comparative effects of vitamin D, dihydrotachysterol and 1alpha-hydroxyvitamin D3 was undertaken in twenty-eight patients with hypoparathyroidism. The vitamin D compounds restored plasma calcium to the normal range in most patients with comparable actions on the gut, bone and kidney. Although the vitamin D compounds had a direct action on kidney and bone in the absence of PTH, the major action in maintaining plasma calcium was on the gut. Plasma phosphate fell due to a reduction in renal tubular reabsorption. Dihydrotachysterol and 1alpha-hydroxyvitamin D3 had significant practical advantages over vitamin D in their rapid onset of action and their relatively short biological half-life.