[Effects of essential trace elements on bone turnover--in relation to the osteoporosis]

Trace Elements are essential for normal growth and development of skeletons in humans and animals. Although they are minor building components in teeth and bone, they play important functional roles in bone metabolism and bone turnover. Fluoride accumulates in new bone formation sites and results in a net gain in bone mass. Aluminum induces impairment of bone formation by the inhibition of osteoblastic function. Magnesium enhances bone turnover by through the stimulation of osteoclastic function. Zinc regulates secretion of calcitonin from thyroid grand and influences on bone turnover. Gallium suppresses bone turnover in humoral hypercalcemia of malignancy in a similar mechanism as aluminum and cadmium. Copper induces low bone turnover by both suppressions of osteoblastic and osteoclastic functions. Iodine as the hormonal forms of thyroxine and triiodothyronine enhances bone turnover. Among the trace elements in bone and hair, significant differences were found in the contents of zinc, copper and manganese between normal subjects and osteoporotic patients. However, exact involvements of the trace elements in osteoporosis have not yet been clarified.