The effect of vitamin D on the B-cell activity of the endocrine pancreas

Hypocalcemia reduces rate of disappearance of glucose from plasma

The influence of hypocalcemia on glucose disposal from plasma was studied in 4.5 to 24 kg weaned, fasted, calcitriol deficient piglets, which suffered from type I inherited pseudo vitamin D deficiency rickets. The plasma glucose concentration of the piglets was clamped to 40% above its preinfusional level by a continuous intravenous infusion of glucose. This suppressed hepatic glucose production. Since the clamped plasma glucose concentration was below its renal threshold, the rate of steady state glucose infusion served as an estimate for glucose disposal from plasma. It was found that hypocalcemia, generated either by calcitriol deficiency or by continuous EDTA infusions, reduced glucose disposal from plasma by 56-76% compared to normocalcemic control piglets. It was suggested that the effect was not compounded by plasma phosphate, calcitriol or insulin. It was further suggested that hypocalcemia depressed the rate of glucose utilization.