Evaluation of Serum Vitamin D Levels in Diabetic Foot Infections: A Cross-Sectional Study in a Tertiary Care Center in South India

BACKGROUND: The impact of diabetic foot infections is enormous in India. Studies on vitamin D levels in diabetes mellitus foot infections are scarce. The primary objective of the present study was to compare the serum vitamin D level between diabetics with foot infections and those without foot infections and the secondary objective was to assess the association between the vitamin D level and the severity of foot infections and outcomes. METHODS: The study included 176 type 2 diabetics who attended Jawaharlal Institute of Postgraduate Medical Education and Research, Pondicherry, India, between September 2012 and June 2014. The serum vitamin D level was measured for 88 diabetics with foot infections (Group 1) and 88 without foot infections (Group 2) using the ELISA 25OH vitamin D DIAsource kit (DIAsource ImmunoAssays S.A., Belgium) and compared. Both groups were followed up for 6 months for outcomes. The qualitative variables were analyzed using the χ2 test and the quantitative variables using the Student t test. The statistical analyses were performed using SPSS, version 17.0. A P value of less than 0.05 was considered significant. RESULTS: The mean serum vitamin D level was not significantly different between the two groups (P=0.306). Among the patients in Group 1 who either required amputations or died, 97.44% had subnormal vitamin D levels in contrast to 59.18% in those who were grafted or achieved wound healing (P=0.001). Among those who achieved wound healing within 6 months, 78.9% had normal vitamin D levels (P=0.0006). CONCLUSION: The study found no significant difference in the serum level of vitamin D between diabetics with and without foot infections. However, vitamin D deficiency was associated with a poor outcome in diabetics with foot infections.