This Article Full Text Full Text (PDF) Submit a related Letter to the Editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Åkesson, K. Articles by Baylink, D. J. Search for Related Content PubMed PubMed Citation Articles by Åkesson, K. Articles by Baylink, D. J.

Effects of Short-Term Calcium Depletion and Repletion on Biochemical Markers of Bone Turnover in Young Adult Women¹

Mineral Metabolism, Jerry L. Pettis Memorial Veterans Administration Medical Center (K.Å., K.-H.W.L., D.J.B.), Loma Linda, California 92357; and the Departments of Medicine (K.Å., K.-H.W.L., D.J.B.), Biochemistry (K.-H.W.L., D.J.B.), and Nutrition (P.J., E.I.), Loma Linda University, California 92350

Address all correspondence and requests for reprints to: K.-H. William Lau, Ph.D., Mineral Metabolism (151), Jerry L. Pettis Memorial Veterans Administration Medical Center, 11201 Benton Street, Loma Linda, California 92357. E-mail: laub{at}llvamc.va.gov

The skeletal responses to calcium depletion and repletion in rodents have been well characterized, but those in humans are poorly understood. The present study sought to evaluate the effects of short term dietary calcium depletion and repletion on biochemical markers of bone turnover in 15 young Caucasian women (age, 21–30 yr). The study contained 3 phases: 1) 5 days of a regular diet containing more than 800 mg/day calcium to establish baseline values (baseline phase), 2) 22 days of a restricted diet containing less than 300 mg/day calcium (depletion phase), and 3) 7 days of a normal diet containing more than 800 mg/day calcium (repletion phase). Serum and urine samples were obtained from each subject during the baseline phase; on the first, second, and last days of the depletion phase; and on the third and last days of the repletion phase. Serum levels of calcium, PTH, 1,25-dihydroxyvitamin D₃, osteocalcin, and C-terminal type I procollagen peptide (PICP) and urinary levels of calcium and deoxypyridinoline were determined. Serum and urinary calcium levels were significantly reduced, and serum PTH and 1,25-dihydroxyvitamin D₃ levels were markedly increased during depletion. These changes were completely reversed after 1 week of repletion. Depletion also rapidly and significantly increased the urinary deoxypyridinoline level, indicating increased bone resorption. The increase also returned rapidly to baseline upon repletion. Calcium depletion had contrasting effects on bone formation markers; whereas depletion significantly reduced the serum PICP level, it significantly increased serum osteocalcin level. Past histomorphometric studies in rodents indicated that the number of mature but inactive osteoblasts was increased during depletion despite an inhibition of bone formation. Thus, it is speculated that although the reduction in serum PICP reflected the depletion-associated inhibition of bone formation, the increase in serum osteocalcin could represent this depletion-related increase in osteoblast number. During repletion, serum osteocalcin remained elevated above baseline. PICP recovered from its depressed level and increased above baseline, a finding consistent with past histomorphometric findings of increased bone formation during repletion. In summary, this study confirms that 1) a short calcium depletion period produces calcium stress in young women, which leads to rapid stimulation of bone resorption and inhibition of bone formation; and 2) a subsequent calcium repletion period could lead to a compensatory increase in bone formation. In conclusion, the skeletal responses to calcium depletion/repletion in young women may be similar to those in rodents.

This article has been cited by other articles:

				N. M. Esser, P. C. Hoffman, W. K. Coblentz, M. W. Orth, and K. A. Weigel The effect of dietary phosphorus on bone development in dairy heifers J Dairy Sci, April 1, 2009; 92(4): 1741 - 1749. [Abstract] [Full Text] [PDF]

				D. T. Shaw, D. W. Rozeboom, G. M. Hill, M. W. Orth, D. S. Rosenstein, and J. E. Link Impact of supplement withdrawal and wheat middling inclusion on bone metabolism, bone strength, and the incidence of bone fractures occurring at slaughter in pigs J Anim Sci, May 1, 2006; 84(5): 1138 - 1146. [Abstract] [Full Text] [PDF]

				S. L. Ferrari, J.-P. Bonjour, and R. Rizzoli Fibroblast Growth Factor-23 Relationship to Dietary Phosphate and Renal Phosphate Handling in Healthy Young Men J. Clin. Endocrinol. Metab., March 1, 2005; 90(3): 1519 - 1524. [Abstract] [Full Text] [PDF]

				M. U. Karkkainen, C. J. Lamberg-Allardt, S. Ahonen, and M. Valimaki Does it make a difference how and when you take your calcium? The acute effects of calcium on calcium and bone metabolism Am. J. Clinical Nutrition, September 1, 2001; 74(3): 335 - 342. [Abstract] [Full Text]

				J. Guillemant, H.-T. Le, C. Accarie, S. T. du Montcel, A.-M. Delabroise, M. J Arnaud, and S. Guillemant Mineral water as a source of dietary calcium: acute effects on parathyroid function and bone resorption in young men Am. J. Clinical Nutrition, April 1, 2000; 71(4): 999 - 1002. [Abstract] [Full Text] [PDF]

				C. Libanati, D. J. Baylink, E. Lois-Wenzel, N. Srinivasan, and S. Mohan Studies on the Potential Mediators of Skeletal Changes Occurring during Puberty in Girls J. Clin. Endocrinol. Metab., August 1, 1999; 84(8): 2807 - 2814. [Abstract] [Full Text]