Low Vitamin D May Contribute to Poor Diabetes Control

Low Vitamin D levels have been suspected to be a risk factor for glucose intolerance, and several studies suggest an active role for vitamin D in functional regulation of the pancreatic beta cells.  As such, Esther Krug, from The Johns Hopkins University School of Medicine (Maryland, USA), and colleagues studied the medical charts of 124 patients with Type 2 diabetes, ages 36 to 89 years, who saw an endocrine outpatient clinic for specialty care during a five-year period. As part of their clinic evaluation, serum 25-hydroxyvitamin D levels were measured, and the researchers divided the patients into quartiles based on vitamin D level. The team found that despite receiving regular primary care visits before referral to the endocrine clinic, 91% of patients had either vitamin D deficiency (defined as a level below 15 ng/dL) or insufficiency (15 to 31 ng/dL).  Additionally, the researchers found an inverse relationship between the patients' blood levels of vitamin D and their hemoglobin A1c value, a measure of blood sugar control over the past several months. Lower vitamin D levels were discovered in patients with higher average blood sugars as measured by HbA1c. They urge that their findings “underscore the importance of aggressive screening and supplementation …  Since majority of type 2 diabetic patients are diagnosed and treated by primary care providers, screening and Vit D supplementation as part of routine primary care may improve health outcomes of this highly prevalent condition.”