Citrate and action of vitamin D on calcium and phosphorus metabolism.

GUROFF, GORDON, HECTOR F. DELUCA, AND HARRY STEENBOCK. Citrate and action of vitamin D on calcium and phosphow metabolism. Am. J. Physiol. 20&J: 833-836. 1c~63.-Pantothenic acid and pyridoxine deficiencies in rats greatly minimized the rise in serum citrate following vitamin D administration without affecting the rise in serum calcium, serum phosphorus, and femur ash. In addition, pyridoxine deficiency reduced the response of bone citrate to the administration of vitamin D. The administration of cortisone acetate to rats on a low-calcium diet completely prevented the response of serum and bone citrate to vitamin D administration while having no effect on the response of serum calcium to vitamin D. These findings make it unlikely that an elevated citrate content of extracellular fluid and bone mediates the basic effects of vitamin D on mineral metabolism.