Background and Objective: Bone mineral deficiency continues to occur in extremely-low-birth-weight (ELBW) infants despite formulas enriched in calcium (Ca) and phosphorus (P). This study tested whether extra enteral Ca supplementation increases bone mineral content (BMC) and prevents dolichocephalic head flattening and myopia in ELBW infants.
Study Design: Infants 401 to 1000 birth weight receiving enteral feeds were randomized to receive feeds supplemented with Ca-gluconate powder or pure standard feeds. The main outcome measures were the excretion of Ca and P by weekly spot urine measurements, the degree of dolichocephalic deformation (fronto-occipital diameter to biparietal diameter ratio, FOD/BPD) at 36 weeks postmenstrual age, and the BMC (by dual-energy x-ray absorptiometry) at discharge. Cycloplegic refraction was measured at 18 to 22 months corrected age.
Patients and Results: Ninety-nine ELBW infants with a gestational age of 26 weeks (23–31) (median [minimum-maximum]) were randomized at a postnatal age of 12 days (5–23) weighing 790 g (440–1700). Urinary Ca excretion increased and P excretion decreased in the Ca-supplemented group. Total BMC was 89.9 ± 2.4 g (mean ± SE) in the supplemented group and 85.2 ± 2.6 g in the control group (P = 0.19). The FOD/BPD was 1.50 (1.13–1.69, mean ± SD [standard deviation]) and 1.47 (1.18–1.64) in the supplemented and control groups, and the refraction 0.98 ± 1.23 and 1.40 ± 1.33 dpt (P = 0.68), respectively in 64 ELBW infants (79% of survivors) at 2-year follow-up.
Conclusions: Extra enteral Ca supplementation did not change BMC, head shape, or refraction. The decreased P excretion may reflect P deficiency in infants receiving extra Ca, preventing improved bone mineral accretion.
*Miami Children's Hospital, Miami, Florida
†Departamento de Pediatria, P. Universidad Catolica de Chile, Santiago, Chile
‡Department of Nutrition Sciences
§School of Optometry, University of Alabama at Birmingham, Birmingham
||Division of Neonatology, Department of Pediatrics, University of Alabama at Birmingham
¶Section of Neonatology and Pediatric Critical Care, University Children's Hospital, Ulm
#Division of Neonatology, Children's Hospital, University Center for Women and Children, Leipzig, Germany.
Address correspondence and reprint requests to Ulrich H. Thome, MD, Division of Neonatology, University Center for Women and Children, Liebigstrasse, 20a, 04103, Leipzig, Germany (e-mail: firstname.lastname@example.org).
Received 26 February, 2010
Accepted 1 March, 2011
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Supported by NIH grant P30DK56336 to the UAB Clinical Nutrition Research Unit.
www.clinicaltrials.gov registration no. NCT00892476.
The authors report no conflicts of interest.
Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Website ().