RELATIONSHIP BETWEEN SERUM VITAMAIN D LEVELS AND INSULIN RESISTANCE: AN INTEGRATIVE LITERATURE REVIEW

Abstract

Vitamin D has been investigated for its potential relationship with glucose metabolism and insulin resistance. This study aimed to analyze the association between serum vitamin D levels and insulin resistance in adults. An integrative literature review was conducted using the PubMed/MEDLINE, SciELO, and LILACS databases between May and June 2026. A total of 1,948 records were identified, and 18 studies were included in the final sample after applying the selection criteria. The findings predominantly indicated associations between lower serum concentrations of 25-hydroxyvitamin D [25(OH)D] and greater insulin resistance, frequently assessed using the HOMA-IR index. However, intervention studies reported heterogeneous results, with variable effects of vitamin D supplementation on metabolic markers. It is concluded that lower serum vitamin D levels are frequently associated with greater insulin resistance in adults, although the available evidence does not establish a direct causal relationship. Longitudinal studies and more robust clinical trials are needed to clarify this association.