Aim: The aim of the study was to assess vitamin D status in patients with type 2 diabetes (T2D) and diabetic foot ulcers (DFU).

Material and Methods: A total of 224 patients with T2D, mean age 59.2±10.1 years, BMI 31.5±6.3 kg/m2 and eGFR ≥ 45 ml/min/1.73m2, not on vitamin D supplementation, were enrolled in a cross-sectional study. Subjects were divided in two groups - with DFU (n=61) and non-DFU (n=163). The non-DFU group was subdivided into groups with peripheral neuropathy (n=106) and without any complications (n=57). Neuropathy was assessed by standard clinical tests (10g monofilament and 128 Hz tuning fork). Serum 25(OH)D was assessed by ELISA method.

Results: 25(OH)D level was 12.7 ng/ml (IQR 9.35-18.1 ng/ml) in the studied cohort, which is below the sufficient range (sufficient > 30 ng/ml; insufficiency - 20-30 ng/ml; deficiency 10-20 ng/ml, severe deficiency < 10 ng/ml). The DFU group presented with significantly lower 25(OH)D level as compared to non-DFU group, 12.08 ng/ml (IQR 8.5-15.5 ng/ml) vs. 13.50 ng/ml (IQR 9.6-18.6 ng/ml), p=0.006; 86% of DFU patients being with vitamin D deficiency and severe deficiency. There was no difference in diabetes duration (p=0.096), whereas there was a significant difference in eGFR in DFU group as compared to non-DFU group (81±20 ml/min/1.73m² vs. 89±19 ml/min/1.73m², p=0.008). No relationship was established between 25(OH)D levels and BMI in both groups. The subanalysis of non-DFU group demonstrated significantly lower 25(OH)D level in patients with peripheral neuropathy as compared to patients without any complications - 12.5 ng/ml (IQR 9-17 ng/ml) vs. 16.2 ng/ml (IQR 10-21 ng/ml), p=0.027. There was no difference in serum calcium levels between the different groups.

Conclusion: Patients with DFU and diabetic neuropathy are at higher risk of low 25(OH)D levels probably because of poor self-care and less sunlight exposure. Therefore, this population should be screened for vitamin D deficiency as it may lead to poor wound healing.


A.S. Todorova: None. R. Dimova: Consultant; Self; Amgen, Boehringer Ingelheim International GmbH. Speaker’s Bureau; Self; Sanofi, Wörwag Pharma. N. Chakarova: None. M. Serdarova: None. G. Grozeva-Damyanova: None. P. Tsarkova: None. T. Tankova: Board Member; Self; Amgen, Boehringer Ingelheim International GmbH, Eli Lilly and Company, Merck Sharp & Dohme Corp., Mundipharma International, Novo Nordisk A/S, Sanofi. Speaker’s Bureau; Self; AstraZeneca, Boehringer Ingelheim International GmbH, Sanofi, Servier. E.B. Jude: Speaker’s Bureau; Self; AstraZeneca, Novo Nordisk Inc., Sanofi. Other Relationship; Self; Lilly Diabetes, Menarini Group.

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