This meta- analysis concludes that hypovitaminosis D is associated with increased risk of hyperglycemia both in diabetic and non-diabetic subjects .
There is evidence that vitamin D status is associated with type 2 diabetes .
Many observational studies have been performed investigating the relationship of vitamin D status and circulating biomarkers of glycemic regulation .
To find out whether this association holds , we conducted a systematic review and meta- analysis of cross sectional and longitudinal studies .
Decreased Serum Concentrations of 25-Hydroxycholecalciferol Are Associated With Increased Risk of Progression to Impaired Fasting Glucose and Diabetes
OBJECTIVE To study the association between vitamin D status and the risk of incident impaired fasting glucose ( IFG ) and diabetes  in a population -based cohort of diabetes-free subjects . RESEARCH DESIGN AND METHODS In a historical prospect i ve cohort study of subjects from the Clalit Health Services data base , which includes information on nearly 4 million people , diabetes-free subjects aged 40–70 years with serum 25-hydroxycholecalciferol ( 25-OHD ) measurements available were followed for 2 years to assess the development of IFG and diabetes in five 25-OHD subgroups : ≥25 , 25.1–37.5 , 37.6–50 , 50.1–75 , and > 75 nmol/L. RESULTS The baseline cohort included 117,960 adults : 83,526 normoglycemic subjects and 34,434 subjects with IFG . During follow-up , 8,629 subjects ( 10.3 % of the normoglycemic group ) developed IFG , and 2,162 subjects ( 1.8 % of the total cohort ) progressed to diabetes . A multivariable model adjusted for age , sex , population group , immigrant status , BMI , season of vitamin D measurement , LDL and HDL cholesterol , triglycerides , estimated glomerular filtration rate , history of hypertension or cardiovascular disease , Charlson comorbidity index , smoking , and socioeconomic status revealed an inverse association between 25-OHD and the risk of progression to IFG and diabetes . The odds of transitioning from normoglycemia to IFG , from normoglycemia to diabetes , and from IFG to diabetes in subjects with a 25-OHD level ≤25 nmol/L were greater than those of subjects with a 25-OHD level > 75 nmol/L [ odds ratio 1.13 ( 95 % CI 1.03–1.24 ) , 1.77 ( 1.11–2.83 ) , and 1.43 ( 1.16–1.76 ) , respectively ] . CONCLUSIONS Vitamin D deficiency appears to be an independent risk factor for the development of IFG and diabetes
This meta- analysis concludes that hypovitaminosis D is associated with increased risk of hyperglycemia both in diabetic and non-diabetic subjects .
There is evidence that vitamin D status is associated with type 2 diabetes .
Many observational studies have been performed investigating the relationship of vitamin D status and circulating biomarkers of glycemic regulation .
To find out whether this association holds , we conducted a systematic review and meta- analysis of cross sectional and longitudinal studies .