A randomized, double‐blind, acute crossover, bioavailability study comparing calcium absorption of two calcium formulations in healthy women
Bibliographic record
Abstract
Aging of the North American population has increased the incidence of osteoporosis causing concern to health care providers. This study tested the pharmacokinetics of two calcium sources and their relative effects on parathyroid hormone (PTH). Calcium amino acid chelate and calcium carbonate were studied. Fifteen healthy female subjects, ages 25 to 45, having 25(OH) D (vitamin D) levels between 50 nmol/L and 125 nmol/L and a BMI >;20 and ≤35 kg/m 2 were included. Subjects followed a low calcium diet 7 days prior to and during the clinic test period. Blood samples collected at pre‐dose, 30 minutes, 2, 4, 6, 9, and 12 hours post‐dose were assessed for serum calcium and parathyroid hormone. Subjects administered calcium amino acid chelate had 16.6% higher serum calcium 4 hours post‐dose compared to calcium carbonate. There were no significant differences in serum calcium AUC (0–12h) , C max , and T max between groups. Subjects on calcium amino acid chelate had significantly lower parathyroid hormone levels compared to those on calcium carbonate (P=0.012). The significantly lower values of serum PTH at 4h for calcium amino acid chelate coincided with the maximum concentration of calcium reached in the serum for this formulation. Calcium amino acid chelate produced a significant suppression in serum PTH levels during the test period, suggesting that this formulation was more bioavailable than the calcium carbonate formulation. This study was sponsored by Biotron Laboratories, Inc.
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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) | 0.002 | 0.001 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.001 | 0.002 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.002 | 0.002 |
| Insufficient payload (model declined to judge) | 0.004 | 0.001 |
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".