Relationship of total and calculated free 25-hydroxyvitamin D to biomarkers and metabolic indices in healthy children
Bibliographic record
Abstract
ABSTRACT Context: Vitamin D status is usually assessed by serum total 25-hydroxyvitamin D. Whether free 25-hydroxyvitamin D measures better correlate with various clinical outcomes is unclear. Objective: To identify correlations between total 25-hydroxyvitamin D (t25-OHD), calculated and direct measures of free 25-OHD, and to identify associations of these measures with other outcomes in children, across the 6 common GC haplotypes. Design: Healthy urban-dwelling children underwent measurement of relevant variables. Setting: Academic medical center Participants: Healthy, urban-dwelling children, 6 months to 10 yrs old, predominantly of Hispanic background and representative of all common GC haplotypes. Intervention: None Main Outcome Measures: Total and free 25-OHD and 1,25(OH)2D, calcium, phosphate, PTH, glucose, insulin, aldosterone, and renin. Results: Mean t25-OHD [26.3±6.7ng/ml; 65.8±16.8nmol/L] were lowest in the GC2 genotype. Mean t1,25(OH)2D [57.6±16.5pg/ml; 143.9±41.3pmol/L], were lowest in GC1f/1f, GC1f/2, and GC2/2 groups. T25-OHD correlated strongly with circulating free 25-OHD (cf25-OHD) (r=0.89) and directly measured free 25-OHD (dmf25-OHD) (r=0.69). Cf25-OHD correlated with dmf25-OHD (r=0.69) (p<0.001 for all). t25-OHD inversely correlated with BMI (r=-0.191; p=0.006), skin reflectometry, and systolic blood pressure. T25-OHD correlated with fasting insulin and HOMA-IR, however significance for these correlations were not evident after adjustment for BMI. PTH inversely correlated with all measures of 25-OHD, but most strongly with t25-OHD. Conclusions: Measure of circulating total and free 25-OHD are comparable measures of vitamin D status in heathy children. Correlations are similar with other outcome variables, however t25-OHD remains the strongest correlate of circulating PTH and other variables. These data argue against routine refinement of the t25-OHD measure using currently available assessments of free 25-OHD.
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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 | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".