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Voldoende calcium al belangrijk voor meisjes in
de puberteit.*
Uit een lange termijn studie blijkt dat vrouwen
die reeds op jeugdige leeftijd extra calcium nemen daar in hun latere leven
grote voordelen van hebben en wellicht zo botontkalking op latere leeftijd
kunnen voorkomen.
Calcium
supplementation and bone mineral density in females from childhood to young
adulthood: a randomized controlled trial1,2,3
Velimir
Matkovic, Prem K Goel, Nancy E Badenhop-Stevens, John D Landoll, Bin Li,
Jasminka Z Ilich, Mario Skugor, Larry A Nagode, Stacey L Mobley, Eun-Jeong Ha,
Thomas N Hangartner and Albert Clairmont
1 From the Osteoporosis Prevention and
Treatment Center, the Bone and Mineral Metabolism Laboratory, and the
Departments of Physical Medicine & Rehabilitation, Medicine, and Nutrition,
Davis Medical Research Center (VM, NEB-S, JDL, E-JH, and AC) and the Departments
of Statistics (PKG and BL) and Veterinary Biosciences (LAN), The Ohio State
University, Columbus; the School of Allied Health, University of Connecticut,
Storrs (JZI); the Department of Endocrinology, Cleveland Clinic, Cleveland (MS);
the Nutrition Care Directorate, Walter Reed Army Medical Center, Washington, DC
(SLM); and the Bone Imaging Laboratory, Wright State University, Dayton, OH
(TNH)
Background:
Short-term studies established that calcium influences bone accretion
during growth. Whether long-term supplementation influences bone
accretion in young adults is not known.
Objective: This
study evaluated the long-term effects of calcium supplementation on
bone accretion among females from childhood to young adulthood.
Design: A 4-y
randomized clinical trial recruited 354 females in pubertal stage 2
and optionally was extended for an additional 3 y. The mean dietary
calcium intake of the participants over 7 y was
ca.
830 mg/d; calcium-supplemented persons received an additional
ca. 670 mg/d. Primary outcome variables were distal and proximal radius
bone mineral density (BMD), total-body BMD (TBBMD), and metacarpal
cortical indexes.
Results:
Multivariate analyses of the primary outcomes indicated that
calcium-supplementation effects vary over time. Follow-up univariate
analyses indicated that all primary outcomes were significantly
larger in the supplemented group than in the placebo group at the
year 4 endpoint. However, at the year 7 endpoint, this effect
vanished for TBBMD and distal radius BMD. Longitudinal models for
TBBMD and proximal radius BMD, according to the time since menarche,
showed a highly significant effect of supplementation during the
pubertal growth spurt and a diminishing effect thereafter. Post hoc
stratifications by compliance-adjusted total calcium intake and by
final stature or metacarpal total cross-sectional area showed that
calcium effects depend on compliance and body frame.
Conclusions:
Calcium supplementation significantly influenced bone accretion in
young females during the pubertal growth spurt. By young adulthood,
significant effects remained at metacarpals and at the forearm of
tall persons, which indicated that the calcium requirement for growth
is associated with skeletal size. These results may be important for
both primary prevention of osteoporosis and prevention of bone
fragility fractures during growth. (Jan. 2005)