[Effect of thyroid and adrenal hormones on the course of hypervitaminosis A and D]

Tests staged on normal and hypophysectomized rats demonstrated thyroxin to potentiate the general toxic effect of ergocalciferol, with final death of the animals. At the same time, the blood calcium content in animals receiving thyroxin decreases under the effect of the latter. Hydrocortisone, while producing no effect on the high calcium content in the blood of the animals receiving ergocalciferol, attenuates the general toxic action of the latter. These data point to the possibility of dissociating the general toxic action of ergocalciferol and its influence on the blood calcium level, which disproves the existing notion on the correlation between general toxic action of ergocalciferol and hypercalcemia produced by it. Thyroxin and hydrocortisone do not have any effect on the nature of the action exerted by high doses of vitamin A.