Lowered serum ionized calcium in insulin treated diabetic subjects.

The concentration of ionized calcium at pH 7.40, [Ca2+]7.4, in serum from 43 insulin dependent diabetic patients was lowered in comparison with 47 healthy controls (p less than 0.001), and the difference was biggest in children under sixteen. Serum total calcium, phosphate, and parathyroid hormone were normal, and it is inexplicable why the parathyroid glands did not react by raising serum total calcium. The lowered serum ionized calcium may contribute to the development of diabetic bone loss.