SLR - July 2022 - Kari Phan, DPM
Reference: Lin J, Mo X, Yang Y, Tang C, Chen J. Association between vitamin D deficiency and diabetic foot ulcer wound in diabetic subjects: A meta-analysis. Int Wound J. 2022 May 14.Level of Evidence: Level I
Scientific Literature Review
Reviewed By: Kari Phan, DPM
Residency Program: MetroWest Medical Center – Framingham, MA
Podiatric Relevance:
Diabetic foot ulcers are prevalent in podiatric practices. In studies, patients with diabetic foot ulcers have a higher death rate compared to those without diabetic foot ulcers. There have been studies that suggest vitamin D has effects on a variety of cell processes such as healing, T-cell mediated immunity, cell growth, and insulin secretion and action in the pancreas. There is also previous research revealing positive outcomes of vitamin D in regards to wound healing in diabetic foot ulcers. The aim of this study was to assess the relationship of vitamin D deficiency and diabetic foot ulcers in the diabetic patient population.
Methods:
This is a meta-analysis of studies between 2013 and 2022 to evaluate the association in diabetic patients between vitamin D and foot ulcers. The inclusion criteria were prospective studies, randomized controlled trials, or retrospective studies, the subjects have diabetes mellitus, included vitamin D deficiency, and the study compared diabetic subjects with and without foot ulcers. The exclusion criteria were studies with no evaluation of vitamin D deficiency and diabetic foot ulcers, studies that did not only manage vitamin D deficiency, and studies without comparative outcomes. The meta-analysis focused on studies regarding vitamin D levels that were effected by vitamin D deficiency, vitamin D deficiency prevalence, and severe vitamin D deficiency.
Results:
Between 2013 and 2022 there were a total of 12 studies included for this meta-analysis. There were 7586 subjects with diabetes. Of those, 1565 were diabetics with foot ulcers and 6021 were diabetics without foot ulcers. It was found vitamin D levels were significantly lower in those with diabetic foot ulcers, higher prevalence of vitamin D deficiency in those with diabetic foot ulcers, and higher prevalence of severe vitamin D deficiency in those with diabetic foot ulcers. Limitations to this study were a low number of studies available for this meta-analysis and of the 12 studies there were 4 studies with less than or equal to 100 sample size for subjects.
Conclusions:
Their results show diabetic patients with foot ulcers compared to those without have a significantly lower levels of vitamin D, higher prevalence of vitamin D deficiency, and a higher prevalence of severe vitamin D deficiency. With the limitations in this analysis additional studies with a sample size that is larger is necessary. As the mechanism in which vitamin D levels effect the diabetic foot ulcers are unclear it would be beneficial for further research. Vitamin D has shown to help glycemic control in diabetics with hyperglycemia. Hyperglycemia affects the manufacturing of cytokine which leads to delayed/decreased ulcer healing. Perhaps with the association supplements with vitamin D may assist in healing diabetic foot ulcers.