| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
ORIGINAL RESEARCH COMMUNICATION |
1 From the Center for Human Nutrition, The Johns Hopkins University Bloomberg School of Public Health, Baltimore (KOO); The Johns Hopkins Hospital, Baltimore (MSN and JM); and the Johns Hopkins School of Medicine, Baltimore (FRW).
Background: Early childbearing may limit skeletal consolidation and increase calcium demands in adolescents.
Objective: The purpose of this study was to characterize calcium absorption in pregnant and lactating adolescents.
Design: Fractional calcium absorption was evaluated in 23 adolescents (mean ± SD age: 16.5 ± 1.4 y) during the third trimester of pregnancy (34.7 ± 1.0 wk gestation) and again in 15 of these adolescents 31 ± 8 d after delivery. Eight adolescents were breastfeeding their infants during the follow-up study. Fractional calcium absorption was determined by using oral (46Ca or 44Ca) and intravenous (42Ca) stable calcium isotopes. Total-body and lumbar spine bone mineral density were measured in adolescents during the postpartum period by using dual-energy X-ray absorptiometry.
Results: Fractional calcium absorption was significantly greater during pregnancy than at 3–4 wk postpartum [0.526 ± 0.152 (n = 23) compared with 0.297 ± 0.108 (n = 15); P < 0.0001]. Lumbar spine z scores measured 19–44 d after delivery (n = 15) were significantly associated with calcium intake during pregnancy (y = -3.53 + 0.107x; R2 = 0.355, P < 0.02) and were inversely related to fractional calcium absorption during pregnancy (y = 3.489 - 6.66x; R2 = 0.52, P = 0.002). A total of 33% (5/15) of adolescents had lumbar spine z scores that met the definition of osteopenia (n = 3) or osteoporosis (n = 2) in the early postpartum period.
Conclusions: Calcium absorption in adolescents was significantly higher during the third trimester of pregnancy than in the early postpartum period, and higher calcium intakes during pregnancy appeared to be protective against loss of trabecular bone at the lumbar spine.
Key Words: Adolescents • pregnancy • lactation • calcium absorption • stable isotopes • bone
This article has been cited by other articles:
|
|
 |
|
  S. A. Atkinson, G. P. McCabe, C. M. Weaver, S. A. Abrams, and K. O. O'Brien Are Current Calcium Recommendations for Adolescents Higher than Needed to Achieve Optimal Peak Bone Mass? The Controversy J. Nutr., June 1, 2008; 138(6): 1182 - 1186. [Full Text] [PDF]
|
|
|
|
|
|
F. F. Bezerra, G. M. K. Cabello, L. M. C. Mendonca, and C. M. Donangelo Bone Mass and Breast Milk Calcium Concentration Are Associated with Vitamin D Receptor Gene Polymorphisms in Adolescent Mothers J. Nutr., February 1, 2008; 138(2): 277 - 281. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. D. Parra, B. E. Martinez de Morentin, J. M. Cobo, I. Lenoir-Wijnkoop, and J. A. Martinez Acute Calcium Assimilation from Fresh or Pasteurized Yoghurt Depending on the Lactose Digestibility Status J. Am. Coll. Nutr., June 1, 2007; 26(3): 288 - 294. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. O O'Brien, C. M Donangelo, C. L V. Zapata, S. A Abrams, E M. Spencer, and J. C King Bone calcium turnover during pregnancy and lactation in women with low calcium diets is associated with calcium intake and circulating insulin-like growth factor 1 concentrations Am. J. Clinical Nutrition, February 1, 2006; 83(2): 317 - 323. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
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]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
