In a cross-sectional study published in the journal Menopause, women with lower levels of vitamin D had higher levels of blood glucose.
“Vitamin D plays an important role in bone metabolism,” the researchers wrote. “There is now evidence that a higher serum level of 25-hydroxyvitamin D (25[OH]D) is associated with a lower risk of developing type 2 diabetes mellitus, because it provides better glycemic control, possibly by promoting greater insulin sensitivity, and also by improving pancreatic beta cell function.”
— NAMS (@MenopauseOrg) January 29, 2019
The study included 680 women in Brazil aged between 35 and 74 years. The women provided fasting blood samples so researchers could measure 25(OH)D and glucose levels, and they answered questions about intake of vitamin D supplements.
Mean fasting blood glucose level among all participants was 105 mg/dL. About a quarter (25.6%) of patients had fasting serum 25(OH)D levels <20 ng/mL, while 65.4% had levels <30 ng/mL. Researchers observed a correlation between a serum level <30 ng/mL and blood glucose level ≥100 mg/dL (odds ratio [OR] 1.29, 95% confidence interval [CI] 1.05-1.57), and between a serum level <20 ng/mL and increased blood glucose level (OR 1.25, 95% CI 1.04-1.50).
— Mark S. Frey, DDS (@MarkSFreyDDS) January 25, 2019
During interviews, 24 (3.5%) participants said they use vitamin D supplements, which was negatively associated with high glucose levels, according to the researchers.
“Habitual exposure to the sun also provided the same association, demonstrating that vitamin D deficiencies are associated with high blood glucose levels,” the study authors said in a press release.
Dr. JoAnn Pinkerton, executive director of the North American Menopause Society, said in the release that while the study did not identify a causal relationship, it is still possible that vitamin D levels are connected to type 2 diabetes mellitus.
“Vitamin D supplementation may help improve blood sugar control, but intervention studies are still needed,” she said.