Calcium bioavailability of calcium carbonate and calcium lactate supplements

Calcium intake for the primary prevention of osteoporosis has received much attention. According to the Nutrition and Health Survey in Taiwan, teenage and adult women consume considerably less than the current Recommended Daily Nutrient Allowance (RDNA) of calcium. The purpose of this study was to investigate the calcium bioavailability of calcium carbonate and calcium lactate, two common forms of calcium supplementation. Thirty-eight healthy adults randomly received 900 mg of one of two calcium supplements. Subjects fasted for more than 12 h before taking the calcium supplements. Blood and urine were collected for analysis of serum calcium, serum parathyroid hormone (PTH) at 0, 1, 2, 4, and 5 h, urine calcium at 0, 2, 4, and 5 h, and 24-h urine for creatinine. Results showed that both calcium supplements could increase serum calcium and the urine Ca/creatinine ratio and decrease serum PTH. However, calcium lactate had a faster absorption rate in increasing serum calcium. We concluded that 900-mg calcium supplementation with calcium lactate had higher calcium bioavailabilty compared with calcium carbonate and may produce a greater benefit for the prevention of osteoporosis.