Re: "Circulating 25-Hydroxyvitamin D and Risk of Pancreatic Cancer"
Notice bibliographique
Résumé
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.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,007 | 0,019 |
| Méta-épidémiologie (sens strict) | 0,003 | 0,001 |
| Méta-épidémiologie (sens large) | 0,002 | 0,002 |
| Bibliométrie | 0,005 | 0,003 |
| Études des sciences et des technologies | 0,002 | 0,002 |
| Communication savante | 0,004 | 0,002 |
| Science ouverte | 0,005 | 0,002 |
| Intégrité de la recherche | 0,011 | 0,016 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,015 | 0,032 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».