There may be a meaningful connection between low vitamin D levels and disordered glucose metabolism.
Research published in the American Journal of Clinical Nutrition examined 126 glucose-tolerant adults living in California to explore the relationship between vitamin D status and insulin function. Insulin sensitivity and first- and second-phase insulin responses were measured using a hyperglycemic clamp technique. The researchers found a positive correlation between serum vitamin D levels and insulin sensitivity, along with evidence that low vitamin D levels were associated with impaired pancreatic beta-cell function. Individuals with inadequate vitamin D appeared to be at higher risk for insulin resistance and features of metabolic syndrome. The authors noted that further research is needed to clarify the underlying mechanisms.
Vitamin D status during pregnancy may also influence metabolic risk in offspring. A case-control study published in Diabetes (epublished November 28, 2011) evaluated serum vitamin D levels in 328 pregnant Norwegian women, including 109 who later gave birth to a child diagnosed with type 1 diabetes. The odds of having a child who developed type 1 diabetes were more than twice as high in women with the lowest vitamin D levels compared to those with the highest levels.
Taken together, these findings suggest that vitamin D may play a role in insulin sensitivity, pancreatic function, and long-term metabolic risk—both in adults and during fetal development.
