Validation of New Methodology to Assess Vitamin B12 in Human Milk and Concentrations in Canadian Donor Milk
Bibliographic record
Abstract
Vitamin B12 is essential for infant growth and development, but little is known about concentrations in human milk. In my thesis research I assessed the validity of a new methodology to assess vitamin B12 (B12) concentrations in human milk, measured concentrations and explored predictors of B12 concentrations in donor milk (DM; n=380). Instrument validation (IMMULITE 2000, Siemens) was conducted using standard reference material, standard addition experiments, and cross-validation with gold-standard methodology. B12 concentrations in DM varied greatly among donors (median (IQR) 232 (149, 373) pmol/L). 64% had concentrations <310 pmol/L, a common cut-off for deficiency. B12 concentrations were significantly higher in donors taking a prenatal or B12-containing supplement (β ±SE: 80.3±25.4; p=0.020), and in primiparous versus multiparous donors (36.7±18.2; p=0.044). Further research is needed to understand the clinical implications of these findings for infants receiving DM.
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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 | 0.031 | 0.029 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.002 | 0.002 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.002 | 0.002 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.002 |
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".