Vitamin D and Diabetes in Pakistan: A Comprehensive Review of Existing Literature

Diabetes is rising rapidly across Pakistan, creating economic and managerial pressure on the healthcare system. At the same time, vitamin D deficiency is common throughout the country, creating a natural curiosity about how these two problems might intersect. Vitamin D is known to influence the body's ability to manage glucose, yet studies from Pakistan have shown varied results. In this review, we included observational and interventional human studies conducted in Pakistan that measured serum vitamin D in relation to diabetes prevalence, glycemic control, or complications. A broad range of study designs, including cross-sectional, case-control, cohort, and randomized controlled trials, was considered to capture the diversity of available evidence. Most research came from urban centers and focused on adults with type 2 diabetes. Cross-sectional studies were the most common design, with fewer case-control, cohort, and interventional studies. A key issue across the literature was the lack of uniformity in how vitamin D levels were defined, with many studies using different thresholds or reporting styles. Genetic aspects of vitamin D deficiency were addressed in only a small number of studies. Despite these differences, most studies consistently found very low vitamin D levels among people living with diabetes in Pakistan. The findings point to a strong need for more standardized and methodologically robust research to better clarify how vitamin D fits into the broader picture of diabetes in the Pakistani population. A clearer, more cohesive evidence base will help guide better screening, treatment, and prevention strategies for people at risk.