[Calcium metabolism in the case of vitamin D and K deficiencies]

Moderate vitamin K deficiency was induced in growing rats by 4-week food ration deficient in vitamin K. It was characterized by prolongation of prothrombin time by 35%, and reduced by 23% in vitro calcium absorption by the duodenal disks in the animals provided with vitamin K, producing no significant effect on calcium concentration in the blood serum of rats with varying vitamin providing. Vitamin K deficiency did not influence the concentration of parathormone and 25-hydroxyvitamin D in the blood serum of rats provided with vitamin D, but it did not raise the degree of hyperparathemia in vitamin D deficiency and prevented the normalization of parathormone level after administration of physiological doses of vitamin D to rats deprived of this vitamin.