Effect of rapid correction of vitamin D insufficiency on bone health in breastfed infants born with low vitamin D stores: A randomized, double-blind trial in Montreal, Canada
Bibliographic record
Abstract
Many Canadian infants are born with an insufficient vitamin D status. Maintaining a low serum 25-hydroxyvitamin D [25(OH)D] concentration of less than 50 nmol/L during infancy could have negative impacts on bone health. In order to support a sufficient 25(OH)D concentration, Health Canada currently recommends that all breastfed infants receive a vitamin D supplement of 400 international units per day (IU/d). It has been shown that higher doses of vitamin D allow for a more rapid increase in 25(OH)D which could benefit those born with insufficient status. However, the lack of evidence in this population limits the development of new guidelines. Thus, the primary objective of this thesis was to determine whether current Canadian supplementation guidelines of 400 IU/d are adequate for infants born with vitamin D insufficiency, or if a higher dose (1000 IU/d) is associated with increased bone mineralization. The secondary objective was to test whether a higher status target of 25(OH)D ≥75 nmol/L, irrespective of supplementation dosage, is associated with changes in bone outcomes. In this preliminary analysis from an ongoing double-blinded randomized controlled trial (RCT) (clinicaltrials.gov: NCT02563015), healthy term-born breastfed infants (n=56) were recruited from a hospital in the Montreal area. Infant blood was sampled 24-36 hours after birth for measurement of total serum 25(OH)D concentration (LIAISON, DiaSorin Inc.). Infants with insufficient status <50 nmol/L were randomized to receive either 400 IU/d (n=19) or 1000 IU/d (n=22) cholecalciferol. Infants with sufficient status ≥50 nmol/L (n=15) formed a reference group receiving 400 IU/d. At baseline (≤1 mo), and at 3 mo, bone mineral content (BMC) and bone mineral density (BMD) of the whole body and lumbar spine were measured using dual-energy X-ray absorptiometry (DXA). Anthropometry, demographic and dietary questionnaires were collected. Data were analyzed using a mixed-model ANOVA (SAS, version 9.3). Data are mean ± SD, significance of p<0.05. All mean bone and anthropometric outcomes in the 400 IU/d and 1000 IU/d groups were well within the range of values (mean ± SD) obtained for the reference group from birth to 3 mo, indicating healthy growth. The study population included slightly more male than female infants (32/56) and infants with light skin pigmentation (41/56). Breastfeeding rates were comparable between groups (p=0.32) with 91% (51/56) of infants received breast milk up to 3 mo of age, and of those 82% (42/51) were exclusively breastfed. By 3 mo, serum 25(OH)D concentration was 77 ± 23 nmol/L for the 400 IU/d group and 131 ± 39 nmol/L for the 1000 IU/d group (p<0.0001). No significant differences in absolute or weight-adjusted BMC of the whole body or lumbar spine, or BMD of the lumbar spine were observed between groups. Percent change of total body less head BMC from baseline was significantly higher in the 1000 IU/d group compared to 400 IU/d (46.2 ± 23.5% vs. 37.3 ± 14.8%, p=0.02). Infants in the 1000 IU/d group also had significantly greater length velocity with an average growth rate of 0.5 ± 0.2 cm/mo more than infants receiving 400 IU/d (p=0.03). Additionally, reaching a higher status target of ≥75 nmol/L 25(OH)D was not associated with any differences in bone outcomes. The preliminary results of this study suggest that there may be some advantages in terms of bone mineral accretion and length velocity by 3 mo associated with the use of 1000 IU/d cholecalciferol. Study participants will continue in the trial until 1 y with follow-up to 3 y to assess the longer-term impacts of the interventions.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.003 | 0.002 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.002 | 0.002 |
| Insufficient payload (model declined to judge) | 0.005 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".