Bone density, increased lithium

Ten patients who had taken lithium for less than 1 year and 13 who had taken it for more than 3 years were assessed for alterations in bone metabolism and parathyroid function (654). There were no differences in bone mineral density, serum calcium concentration, or PTH concentration, but both groups had increased bone turnover and the longterm group had nonsignificantly higher calcium and PTH concentrations (including one hyperparathyroid patient who had an adenoma excised). The authors conclusion that lithium therapy is not a risk factor for osteoporosis needs to be tempered by the small sample size, the case of adenoma, and the blood concentration trends. 

Despite lithium-induced increases in serum calcium and PTH concentrations, most recent studies have not shown a reduction in bone mineral density or increased risks of osteoporosis or bone fractures (422). In 26 patients who had taken lithium for at least 10 years, bone mineral density did not differ from controls (423). 

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