TISSUE CALCIFICATION AND RENAL FAILURE PRODUCED BY MASSIVE DOSE VITAMIN D THERAPY OF ARTHRITIS

Abstract

Daily doses of 500,000 and 200,000 I.U. of vit. D administered to 2 patients over a period of 5 mos. and of 6 yrs., respectively, resulted in a marked increase in the concn. of serum Ca and P, azotemia, albuminuria, decreased excretion of phenolsulphonphthalein dye, loss of ability to concentrate urine, and anemia. Hypertension developed in only the 1st patient, the other showed soft tissue calcification of the hands, wrists, and right ankle. Cessation of vit. D therapy was followed by a return of the Ca and P concns. to normal with gradual decrease over a period of mos. in the renal function abnormalities, without complete resolution. The hypertension diminished. The Ca deposited in the soft tissues was almost entirely resorbed. At this time a marked destruction of the bones of the wrists with the calcinosis was evident. These toxic effects were produced in one patient by irradiated ergosterol and in the other by a Whittier process electrically activated vaporized vit. D. The latter has heretofore been considered less toxic. Frequent checks on the renal function, the state of the cardio-vascular system, and the concn. of Ca and P in serum during prolonged therapy with vit. D are urged. Hypercalcemia is to be avoided.