Vitamin D-mediated decrease of Ca2+-pump activity in the rat parotid gland.

In vitro activities of Ca2+-ATPase and 45Ca2+ uptake in microsomes, which were prepared from vitamin D-deficient rat parotid glands, were decreased in parallel by the oral administration of vitamin D3 as compared with those of control animals (r = 0.83). In vivo 45Ca2+ uptake in the parotid glands of vitamin D-deficient rats was also decreased by the oral administration of vitamin D3.