Bibliographic record
Abstract
In their study on circulating 25-dihydroxyvitamin D (25(OH)D) and the risk of pancreatic cancer, Stolzenberg-Solomon et al. found that a high 25(OH)D concentration (≥100 nmol/L) was associated with a statistically significant increase in pancreatic cancer risk. On the basis of these results, the authors concluded, “ … recommendations to increase vitamin D concentrations in healthy persons for the prevention of cancer should be carefully considered” (1, p. 81). However, there are potential health implications of chronic vitamin D deficiency in healthy persons, particularly in populations inhabiting higher geographic latitudes (2) and in those with darker skin pigmentation (3). At 156 nmol/L, the highest 25(OH)D concentration observed in this study cannot be considered as potentially toxic. The authors acknowledge that the range of 25(OH)D levels associated with the cancer risk in this study was below that considered to reflect hypervitaminosis D. In addition, a half-hour skin exposure under the summer sun in a bathing suit can initiate the release of up to 50,000 IU (1,250 μg), 30,000 IU (750 μg), and 10,000 IU (250 μg) of vitamin D into the circulation within 24 hours of the exposure in white, tanned, and dark-skinned individuals, respectively (4). A dose of 250 μg of vitamin D/day for up to 5 months is not expected to elevate circulating 25(OH)D to concentrations greater than 90 ng/mL (225 nmol/L), while doses of less than 25 μg of vitamin D/day are inadequate for maintaining physiologically normal circulating 25(OH)D concentrations of 15–80 ng/mL (37–200 nmol/L) (5). Considering that vitamin D plays an important role in modulating the immune response (4, 6), it is likely not plausible to even suspect a causal relation between moderately elevated levels of circulating 25(OH)D and an increased incidence of pancreatic or other cancers. It may be useful to establish the difference between concentrations of total and free serum 25(OH)D and its active metabolite, 1,25-(OH)2D, among the selected subjects. Pettifor et al. (7) found that, despite normal or near-normal total 1,25-(OH)2D values, most of the patients in their study had elevated free 1,25-(OH)2D suspected to play a role in the pathogenesis of hypercalcemia and vitamin D toxicity. Further research is needed to determine if the observed elevated 25(OH)D levels in pancreatic cancer patients could be associated with genetic variants of vitamin D receptors or abnormal vitamin D metabolic pathways. Ramagopalan et al. (8) provide a comprehensive high-resolution map of numerous vitamin D receptor binding sites with influence on the immune and other functional pathways, and they discuss observed significant enrichment in regions near autoimmune and cancer-associated genes. An unbalanced metabolic transformation or inadequate receptor binding may lead to plasma accumulation of active/inactive vitamin D metabolites and an impaired immune response, which could increase the probability of developing not only pancreatic but also other cancers. Hence, although seemingly paradoxical, the elevated levels of circulating 25(OH)D observed by Stolzenberg-Solomon et al. (1) may indicate a functional vitamin D hypo- rather than hypervitaminosis. Conflict of interest: none declared.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.007 | 0.019 |
| Meta-epidemiology (narrow) | 0.003 | 0.001 |
| Meta-epidemiology (broad) | 0.002 | 0.002 |
| Bibliometrics | 0.005 | 0.003 |
| Science and technology studies | 0.002 | 0.002 |
| Scholarly communication | 0.004 | 0.002 |
| Open science | 0.005 | 0.002 |
| Research integrity | 0.011 | 0.016 |
| Insufficient payload (model declined to judge) | 0.015 | 0.032 |
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".