This Article Full Text Full Text (PDF) Submit a related Letter to the Editor Purchase Article View Shopping Cart 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 Prentice, A. Articles by Fairweather-Tait, S. Search for Related Content PubMed PubMed Citation Articles by Prentice, A. Articles by Fairweather-Tait, S.

Biochemical Markers of Calcium and Bone Metabolism during 18 Months of Lactation in Gambian Women Accustomed to a Low Calcium Intake and in Those Consuming a Calcium Supplement¹

Medical Research Council Dunn Nutrition Unit, Cambridge, United Kingdom and Keneba, The Gambia; and Institute of Food Research, Norwich, United Kingdom

Address all correspondence and requests for reprints to: Dr. Ann Prentice, Micronutrient Research, Medical Research Council Dunn Nutrition Unit, Downham’s Lane, Milton Road, Cambridge, United Kingdom CB4 1XJ. E-mail: ann.prentice{at}mrc-dunn.cam.ac.uk

Abstract

The effect of 18 months of lactation on indexes of calcium and bone metabolism was studied in 60 Gambian women accustomed to a very low calcium intake. Half the women consumed a calcium supplement from 10 days postpartum for 52 weeks (supplement, 714 mg Ca/day; total Ca intake, 992 ± 114 mg/day), and half consumed placebo (total Ca intake, 288 ± 128 mg/day). Fasting blood and 24-h urine samples were collected at 1.5, 13, 52, and 78 weeks of lactation and analyzed for calciotropic hormones (intact PTH, 1,25-dihydroxyvitamin D, and calcitonin), bone turnover markers (osteocalcin, bone alkaline phosphatase, and urinary deoxypyridinoline), and plasma minerals (calcium and phosphate). The first months of lactation were associated with increased bone turnover and plasma phosphate, and decreased PTH and 1,25-dihydroxyvitamin D. These effects diminished by 52 weeks, although breast milk volumes remained high. The Gambians had higher PTH, 1,25-dihydroxyvitamin D, and bone formation than British women with a greater customary calcium intake. None of the biochemical indexes was affected by calcium supplementation, with the possible exception of bone alkaline phosphatase (-29% at 52 weeks; P = 0.015). These data demonstrate that lactation-associated changes in calcium and bone metabolism are physiological and are independent of dietary calcium supply in women with very low calcium intakes.

This article has been cited by other articles:

				F. F Bezerra, L. M. Mendonca, E. C Lobato, K. O O'Brien, and C. M Donangelo Bone mass is recovered from lactation to postweaning in adolescent mothers with low calcium intakes Am. J. Clinical Nutrition, November 1, 2004; 80(5): 1322 - 1326. [Abstract] [Full Text] [PDF]

				C. L Vargas Zapata, C. M Donangelo, L. R Woodhouse, S. A Abrams, E M. Spencer, and J. C King Calcium homeostasis during pregnancy and lactation in Brazilian women with low calcium intakes: a longitudinal study Am. J. Clinical Nutrition, August 1, 2004; 80(2): 417 - 422. [Abstract] [Full Text] [PDF]

				A. Prentice Micronutrients and the Bone Mineral Content of the Mother, Fetus and Newborn J. Nutr., May 1, 2003; 133(5): 1693S - 1699. [Abstract] [Full Text] [PDF]

				F. F. Bezerra, F. P. Laboissiere, J. C. King, and C. M. Donangelo Pregnancy and Lactation Affect Markers of Calcium and Bone Metabolism Differently in Adolescent and Adult Women with Low Calcium Intakes J. Nutr., August 1, 2002; 132(8): 2183 - 2187. [Abstract] [Full Text] [PDF]

				E. G. Vajda, B. M. Bowman, and S. C. Miller Cancellous and Cortical Bone Mechanical Properties and Tissue Dynamics During Pregnancy, Lactation, and Postlactation in the Rat Biol Reprod, September 1, 2001; 65(3): 689 - 695. [Abstract] [Full Text] [PDF]

				B. C. Nordin Calcium requirement is a sliding scale Am. J. Clinical Nutrition, June 1, 2000; 71(6): 1381 - 1383. [Full Text] [PDF]

				A. Prentice Maternal calcium metabolism and bone mineral status Am. J. Clinical Nutrition, May 1, 2000; 71(5): 1312S - 1316. [Abstract] [Full Text] [PDF]

				H. J. Kalkwarf, B. L. Specker, and M. Ho Effects of Calcium Supplementation on Calcium Homeostasis and Bone Turnover in Lactating Women J. Clin. Endocrinol. Metab., February 1, 1999; 84(2): 464 - 470. [Abstract] [Full Text]

				S. A. Abrams Bone Turnover during Lactation--Can Calcium Supplementation Make a Difference? J. Clin. Endocrinol. Metab., April 1, 1998; 83(4): 1056 - 1058. [Full Text]