Biochemical effects of a single oral dose of calcium on bone metabolism in elderly Chinese women

The biochemical effects of a single oral dose of 10 mmol of calcium on certain blood and urine variables were studied in 20 elderly postmenopausal subjects (mean age 72.3±6.2 years) with a very low dietary calcium intake (mean 7.2±3 mmol/day). Twelve hours after calcium administration, the plasma total calcium, phosphate and bicarbonate, and the urinary calcium/creatinine ratio rose, while the plasma parathyroid hormone and chloride, and urinary hydroxyproline/creatinine and phosphate/creatinine ratios fell. These results show that a single oral dose of calcium suppresses bone resorption in elderly women with low dietary calcium intake, and that long-term supplementation may be important in the prevention of osteoporosisrelated fractures.