Vitamin D Screening of Healthy Newborns in Montreal
Bibliographic record
Abstract
National data on vitamin D status is lacking for neonates in Canada. The Institute of Medicine defines vitamin D deficiency as <30 nmol/L of 25(OH)D and recommends that 25(OH)D be at least 50 nmol/L to support bone health. The Canadian Paediatric Society suggests 25(OH)D be between 75 to 225 nmol/L. One out of four healthy term-born infants born to healthy mothers from Quebec City had cord serum 25-hydroxyvitamin D (25(OH)D) concentrations <50 nmol/L. Identifying infants with insufficient vitamin D status at birth will inform health professionals and parents of the need to establish good vitamin D stores early in life. The aim of this study was to assess the feasibility of newborn screening for vitamin D status within 24–36 h of birth. Mothers and their infants from a hospital in the greater Montreal area were studied. A capillary sample (500 μl) was obtained at the same time as other standard screening tests for measurement of total 25(OH)D using a chemiluminescent assay (Liaison, Diasorin). A researcher administered a questionnaire to the mothers to survey ethnicity and immigration status, income, education, supplement use and sun exposure. Inclusion criteria were any singleton healthy term-born infant of appropriate weight for gestational age based on the Arbuckle Canadian growth reference and born to a healthy mother of any race. Mothers were excluded if they had any form of diabetes, preeclampsia, celiac disease, inflammatory bowel disease or took medications that impact vitamin D/mineral metabolism. Data was collected from March to November 2016. Data are mean ± SD or proportions. Relative to all births 30.0% (292/971) did not meet the eligibility criteria. Of the remaining eligible mothers, 52.3% (355/679) agreed to screening. Complete data and blood samples were successfully obtained from 86.5 % (307/355) of participants. Mothers were 32 ± 5.4 years of age, 64.8% identified as white, 60.5% were born in Canada, 56.7% were university educated, 38.5% took a multivitamin during the 3 months before they became pregnant and 92.8% took a multivitamin during pregnancy. Neonates (n=159 male; n=148 female) were born at 40.0 ± 1.0 weeks gestation and had a weight of 3428 ± 378 g with a corresponding weight-for-age z-score of 0.2 ± 0.8. Serum 25(OH)D concentration was 48.0 ± 19.0 nmol/L; National Institutes of Standards and Technology vitamin D control 972a-Level 1 (73.3 +/− 2.8 nmol/L) was measured monthly and was within 2.3% of the reference value. Fifty-six percent (172/307) had a 25(OH)D concentration below 50 nmol/L, 18.2% (56/307) were below 30 nmol/L and 9.8% (30/307) were at or above 75 nmol/L (Figure 1). Overall, screening for vitamin D status was feasible in terms of a high acceptance rate by parents and sufficient sample volume. Given that such a large proportion of the infants were born insufficient warrants further examination into screening for vitamin D status at birth and current supplementation recommendations during pregnancy and for the neonate. Support or Funding Information Supported through a grant from the Canadian Institutes for Health Research, Canada Foundation for Innovation and the Canada Research Chairs Program. Histogram of serum 25(OH)D concentrations from healthy term-born infants of appropriate weight for gestational age (n=307).
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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 | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.002 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".