Intestinal absorption of oyster shell electrolysate.

High voltage electric current was passed through oyster shell powder for electrolysis. The crystalline shape of oyster shell electrolysate appeared to be quite different from that of CaO or CaCO3. Higher serum calcium values were achieved by oral administration of the same amount of as oyster shell electrolysate than as calcium carbonate in vitamin D-deficient rats, suggesting a better intestinal absorption of the former than the latter. In four patients with postoperative hypoparathyroidism with reduced intestinal calcium absorption, the same amount of elementary calcium as oyster shell electrolysate was more effective than calcium carbonate in raising serum calcium in the absence of vitamin D supplement. Oyster shell electrolysate was also more effective in suppressing serum parathyroid hormone concentration than calcium carbonate in two patients with secondary hyperparathyroidism with renal failure. Calcium thus appears to be more readily absorbed from oyster shell electrolysate than from calcium carbonate through intestinal barriers produced by insufficient vitamin D action.