[Serum calcium concentration and the safety of vitamin D therapy]

Vitamin D and its analogues are administered to patients with secondary hyperparathyroidism (SHPT) in chronic renal failure (CRF). Hypercalcemia is one of the complications of this therapy, and is thought to be not rare, though its frequency is not clearly documented. There is a need to monitor serum corrected (ionized) calcium concentration and parathyroid hormone (PTH) in order to administer vitamin D and its analogues safely. Intravenous administration of vitamin D provides advantages over oral administration, though no definite evidence could show which is better. Calcitriol and maxacalcitol are administered intravenously, and the latter is more likely to increase serum calcium concentration than the former. It must be very careful to administer vitamin D to patients with predialysis CRF because hypercalcemia can accelerate progression of renal dysfunction.