Efficiency of intestinal absorption of beta‐carotene (BC) is not correlated with cholesterol (CHL) absorption in humans
Bibliographic record
Abstract
The intestinal absorption of BC and of CHL varies among individuals. Experiments in vitro and in mouse models suggested that BC and CHL shared certain molecular mechanisms of absorption. A study was conducted to investigate the variability in BC absorption and its conversion to vitamin A and to compare the efficiency of absorption of BC with that of CHL. Ten men consumed a 5 mg dose of deuterium labeled BC (BCd8), with 6 subjects repeating the dose 2 months later. Blood was collected hourly for 9 h, and enrichment of chylomicrons with BCd8 and retinyl‐d4 esters (REd4) was determined by HPLC‐MS. CHL absorption was measured in the same subjects by the oral/IV dual isotope ratio method using deuterated CHL and 13C CHL and ranged from 28% to 60%. Chylomicron BCd8 AUC ranged from 0.047 to 0.414 μM‐hr and the CM REd4 AUC ranged from 0.102 to 2.59 μM‐hr. For subjects who repeated the treatment, the total BC absorbed at the two times was correlated (r=0.99; p<0.0001). The conversion of BCd8 to REd4 ranged from 37–77%, and the extent of conversion at the two times was correlated (r=0.77; p=0.08). There is marked inter‐individual variability in BC absorption and conversion to RE. In contrast, intra‐individual variability in BC absorption and its conversion to RE is low. Importantly, there was no correlation between an individual's efficiency of absorption of BC and their efficiency of absorption of CHL (r=0.21; p=0.56). HL049879 & USDA/ARS
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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 | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".