Association Between Vitamin D Status and Metabolic Flexibility in Adults With Type 2 Diabetes
DOI:
https://doi.org/10.61336/jdme.0602.01Keywords:
Vitamin D, metabolic flexibility, type 2 diabetes, insulin resistance, 25-hydroxyvitamin DAbstract
Vitamin D deficiency is common among individuals with type 2 diabetes and has been associated with insulin resistance and metabolic dysfunction. This study evaluated the relationship between serum 25-hydroxyvitamin D concentrations and metabolic flexibility in adults with type 2 diabetes. A cross-sectional study was conducted among 142 adults with established type 2 diabetes. Serum 25-hydroxyvitamin D, fasting glucose, insulin, lipid profile, and HbA1c were assessed. Metabolic flexibility was estimated from changes in respiratory quotient during a standardized fasting-to-fed metabolic assessment. Participants were categorized according to vitamin D status. Individuals with lower vitamin D concentrations demonstrated greater insulin resistance and reduced metabolic flexibility compared with participants with higher vitamin D concentrations. Serum vitamin D was inversely associated with HOMA-IR and positively associated with metabolic flexibility after adjustment for age, sex, BMI, physical activity, and diabetes duration. These findings suggest that vitamin D status may be associated with metabolic flexibility and insulin sensitivity in adults with type 2 diabetes.
References
1. Holick MF. Vitamin D deficiency. N Engl J Med. 2007;357(3):266–281.
2. Pilz S, Kienreich K, Rutters F, de Jongh R, van Ballegooijen AJ, Grübler M, et al. Role of vitamin D in the development of insulin resistance and type 2 diabetes. Curr Diab Rep. 2013;13(2):261–270.
3. Pittas AG, Lau J, Hu FB, Dawson-Hughes B. The role of vitamin D and calcium in type 2 diabetes. J Clin Endocrinol Metab. 2007;92(6):2017–2029.
4. Wacker M, Holick MF. Sunlight and vitamin D: a global perspective for health. Dermatoendocrinol. 2013;5(1):51–108.
5. Samuel VT, Shulman GI. The pathogenesis of insulin resistance. J Clin Invest. 2016;126(1):12–22.
6. Goodpaster BH, Sparks LM. Metabolic flexibility in health and disease. Cell Metab. 2017;25(5):1027–1036.
7. Kelley DE. Skeletal muscle triglycerides: an aspect of regional adiposity and insulin resistance. Diabetes Care. 2002;25(8):1329–1330.
8. Storlien L, Oakes ND, Kelley DE. Metabolic flexibility. Proc Nutr Soc. 2004;63(2):363–368.
9. American Diabetes Association Professional Practice Committee. Facilitating positive health behaviors and well-being: Standards of Care in Diabetes—2026. Diabetes Care. 2026;49(Suppl 1).
10. DeFronzo RA, Ferrannini E, Groop L, Henry RR, Herman WH, Holst JJ, et al. Type 2 diabetes mellitus. Nat Rev Dis Primers. 2015;1:15019.
