Table 2. Exclusion criteria and rationale.

Exclusion criterion	Explanation
Editorials, commentaries, opinion pieces, and literature reviews	Only articles containing primary data will be included in this review.
Articles not available in full text and articles not written in English or German	Full-text availability and language comprehension are necessary for reliable data extraction.
Studies not investigating pancreatic stromal or epithelial cells	Studies focusing on other organs, tissues, or cell types do not correspond to this review’s population.
Studies that do not use human pancreatic cells or tissue or relevant experimental nonhuman models (eg, mice)	These outcomes are irrelevant for this review.
Studies in which vitamin C is investigated exclusively as a risk factor and is not used as an experimental or therapeutic intervention	The aim of this review is to determine the effects of vitamin C as an active intervention, not its association with disease risks or outcomes.
Studies in which vitamin C interventions cannot be distinguished from other interventions	Possible interference from other interventions disrupts the consolidation and interpretation of data.