Vitamin D Deficiency Independently Linked to Type 2 Diabetes, suggests study

A new study published in the Archives of Endocrinology and Metabolism revealed that vitamin D deficiency was independently associated with the presence of type 2 diabetes mellitus (T2DM). The high prevalence of hypovitaminosis D, even among Indigenous populations with abundant sun exposure, highlights the need for routine screening and consideration of vitamin D supplementation as part of diabetes care

This cross-sectional study, conducted between 2020 and 2022, involved 946 Indigenous adults aged 20 years and older from the Tupiniquim and Guarani ethnic groups along Brazil's southeastern coast. This research assessed the vitamin D status of participants by measuring serum 25-hydroxyvitamin D [25(OH)D] levels and examined their association with T2DM. Diabetes was identified through self-reported diagnosis, the use of glucose-lowering medications, or clinical criteria including elevated fasting plasma glucose, oral glucose tolerance test results, or glycated hemoglobin (HbA1c) levels.

The study population had a mean age of 41.3 years, with women accounting for 56.8% of participants. Around 90% belonged to the Tupiniquim ethnic group. A serum 25(OH)D concentration below 30 ng/mL and multiple logistic regression models were used to evaluate the relationship between vitamin D levels and diabetes after accounting for potential confounding factors.

Each 1 ng/mL increase in serum 25(OH)D was associated with a 4% reduction in the odds of having type 2 diabetes. More notably, participants with vitamin D deficiency had a 77% higher risk of T2DM when compared to those whose vitamin D levels were considered adequate.

The findings suggest that maintaining sufficient vitamin D levels may play a role in reducing diabetes risk, despite the the cross-sectional design of this study. Instead, it identifies a strong independent association that warrants further investigation through prospective studies and clinical trials.

Despite residing in a tropical region with high levels of solar exposure, many participants exhibited inadequate vitamin D levels, which highlighted the factors beyond sunlight exposure influencing vitamin D status such as lifestyle, nutrition, skin pigmentation, and metabolic health.

Overall, routine screening for vitamin D deficiency and consideration of supplementation protocols could become valuable components of public health initiatives aimed at improving metabolic health in Indigenous populations.

Source:

Santos, H. C. D., Alvim, R. O., Quinte, G. C., Faria, C. P., Silva, A. S. D., & Mill, J. G. (2026). Association between vitamin D deficiency and type 2 diabetes in an Indigenous Brazilian population. Archives of Endocrinology and Metabolism, 70(5), e260084. https://doi.org/10.20945/2359-4292-2026-0084