Background: Vitamin D insufficiency has been defined as serum 25-hydroxyvitamin D (25(OH)D) levels below 30 ng/mL and is common among patients with diabetes mellitus (DM) type 2 and the elderly.

Aim & Objectives: Our aim was to investigate clinically meaningful associations implicating low serum levels of 25(OH)D and vascular endothelial growth factor (VEGF) levels in DM type 2.

Methods: Serum 25(OH)D and VEGF levels were determined in 40 patients with DM type 2 and vitamin D insufficiency. Their correlation with markers of advanced diabetic disease (amputation, diabetic foot, proliferative diabetic retinopathy, insulin dependence) as well as with serum biochemical parameters was examined. Subanalyses were performed on men and women.

Results: Compared with males, female patients exhibited lower 25(OH)D levels (p<0.0001) but higher serum VEGF (p=0.018). There was a trend towards an inverse vitamin D - VEGF association. Subanalysis on women showed low serum 25(OH)D levels strongly associated with amputation (p=0.003). High serum VEGF levels were associated with amputation (p=0.038), and marginally with diabetic foot (p=0.058), insulin dependence (p=0.084) and proliferative diabetic retinopathy (p=0.086). Higher serum 25(OH)D levels were associated with serum uric acid (p=0.007), calcium (p=0.042) and albumin levels (p=0.033). Subanalysis on men demonstrated positive correlation between 25(OH)D levels, albumin (p=0.004) and calcium levels (p=0.060, borderline association).

Conclusion: The association between low serum 25(OH)D levels and amputation in women may be inscribed into the wider context portraying vitamin D insufficiency as a poor prognostic factor. Vitamin D insufficiency may exert gender-specific effects in the context of DM type 2.