Low serum levels of 25-hydroxyvitamin D (25[OH]D) may be associated with hyperglycemia,a major risk factor for type 2 diabetes, according to a study published in Menopause.
Researchers conducted a cross-sectional study of 681 women aged 35 to 74 years to evaluate the association between vitamin D deficiency and increased glycemia. Participants were interviewed via an electronic questionnaire; blood samples were collected after an 8-hour fasting period by a sample nurse. Total vitamin D was equated with a total serum concentration of 25(OH)D. Blood glucose levels were categorized as <100 mg/dL vs ≥100 mg/dL; total 25(OH)D was categorized as ≥30 ng/mL vs<30 ng/mL, and as ≥20 ng/mL vs <20 ng/mL.
Results of the study revealed that the minimum and maximum glucose values of the blood samples were 26 and 401 mg/dL, respectively. Of the 681 women evaluated, 176 (25.8%)reported having diabetes; 92 (52.2%) of those women reported using at least 1 hypoglycemic medication, and 30 (17.0%) used insulin.
For serum 25(OH)D, the minimum and maximum values were 5.8 and 55.9 ng/mL,respectively. The prevalence of a serum 25(OH)D level <20 ng/mL was 26.6%and that of a serum 25(OH)D level <30 ng/mL was 65.4%. A total of 24 (3.5%) women reported taking vitamin D supplementation; this was found to be negatively associated with a serum 25(OH)D level <30 ng/mL (OR, 0.44). Sun exposure was also found to be negatively associated with a serum 25(OH)D level <30 ng/mL(OR, 0.68).
A blood glucose level ≥100 mg/dL was positively associated with body mass index,age, and hypertension and with serum 25(OH)D levels <20 and <30 ng/mL. Blood glucose levels ≥100 mg/dL were not associated with vitamin D supplementation (OR, 0.89) or with sunlight exposure (OR, 1.03).
“Our results show that a blood glucose level ≥100 mg/dL correlates positively with serum 25(OH)D levels <30 ng/mL and <20 ng/dL,” the authors concluded.
Valladares T, Cardoso MR, Aldrighi JM. Higher serum levels of vitamin D are associated with lower blood glucose levels [published online January 18, 2019]. Menopause. doi:10.1097/GME.0000000000001308