[Comparative antirachitic activity of 1,25-dihydroxyvitamin D3 and 1 alpha-hydroxyvitamin D3 in the chick]

1,25-dihydroxy vitamin D3 and its synthetic analogue 1 alpha-hydroxy vitamin D3 were administered into chicken at the doses of 0.025, 0.05 and 0.1 micrograms per day within 25 days. Effect of the vitamins was estimated by a net gain of biomass, by biochemical alterations in blood, synthesis of calcium-binding protein, relative mass of parathyroid glands and by content of inorganic residue in bone tissue. Both vitamin preparations exhibited similar antirickety activity.