American Journal of Clinical Nutrition, Vol 47, 1022-1024, Copyright © 1988 by The American Society for Clinical Nutrition, Inc

ORIGINAL RESEARCH COMMUNICATIONS

Monitoring calcium intake in osteoporosis by assay of nephrogenous cyclic AMP

A Licata, D Gall and M Gupta
Department of Endocrinology and Immunopathology, Cleveland Clinic Foundation, OH 44106.

We studied the relationship between urinary and nephrogenous cyclic adenosine monophosphate (CAMP) and intake of calcium in patients with clinical osteoporosis. Serum and urinary Ca, alkaline phosphatase, and CAMP were measured by standard techniques. Lumbar mineral density was assessed by dual photon absorptiometry. Mean (+/- SD) urinary and nephrogenous CAMP was 4.6 +/- 1.4 mumol/g creatinine (0.52 +/- 0.16 mumol/mmol creatinine) and 15 +/- 8.0 nmol/L GF in patients using an extra gram of Ca carbonate daily and 6.5 +/- 2.6 mumol/g creatinine and 32 +/- 18 nmol/L GF in patients consuming dietary Ca (p less than 0.05). Serum Ca was increased (p less than 0.05) in the supplemented group (9.8 +/- 0.4 vs 9.3 +/- 0.6 mg/dL [2.4 +/- 0.099 vs 2.32 +/- 0.14 mmol/L]) but urinary Ca and serum alkaline phosphatase were similar. Bone mineral density was the same in both (0.88 +/- 0.19 vs 0.87 +/- 0.08 g/cm2). We concluded that CAMP is greater in patients with no supplemental Ca in the diet. This test may be useful to assess patient compliance and biological availability of dietary or supplemental Ca.