Lack of Skeletal Lead Accumulation During Calcium Citrate Supplementation

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The deleterious biological effects of lead ingestion are well established. There has been a growing concern that ingestion of certain oyster shell-containing calcium supplements and antacids might contribute to an increased risk of lead poisoning in individuals who consume these products (1). Consumers of calcium supplements and calcium antacids, especially pregnant and lactating women, their unborn fetuses, infants, and small children would thus be exposed to a serious and documented risk of reproductive and developmental harm. Because calcium supplements are invariably prescribed in the prevention and treatment of osteoporosis, elderly osteoporotic individuals may also be at increased risk for lead toxicity. Because the skeleton represents the major repository of lead in the human body, containing 90% or more of total lead content (2), we reasoned that measurement of skeletal lead concentration in osteoporotic individuals before and after calcium supplementation would disclose whether there was significant lead accumulation from administration of calcium supplements.

The patient population was composed of 11 women and three men with a mean age of 60 years (range 38–76). All patients had osteoporosis as evidenced by reduced vertebral bone mass, histologic evidence of osteoporosis, and at least one vertebral fracture. All patients and controls were involved in research protocols approved by the Institutional Review Board on the Use of Human Subjects. A transcortical iliac crest bone biopsy was obtained from each patient after obtaining informed consent and before beginning calcium citrate therapy (400 mg of calcium twice daily as Citracal^®, Mission Pharmacal). A second bone biopsy was procured on the opposite side . . . [Full Text of this Article]

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