SLR - July 2018 - Jordan L. Sullivan

The Effects of Vitamin D Supplementation on Wound Healing and Metabolic Status in Patients with Diabetic Foot Ulcer: A Randomized, Double-Blind, Placebo-Controlled Trial

Reference: The Effects of Vitamin D Supplementation on Wound Healing and Metabolic Status in Patients with Diabetic Foot Ulcer: A Randomized, Double-Blind, Placebo-Controlled Trial. Razzaghi R, Pourbagheri H, Momen-Heravi M, Bahmani F, Shadi J, Soleimani Z, Asemi Z.  J Diabetes Complications. 2017 Apr;31(4):766–772.

Scientific Literature Review

Reviewed By: Jordan L. Sullivan, DPM
Residency Program: Columbia St. Mary’s, Milwaukee Wisconsin

Podiatric Relevance: Diabetic foot ulcerations are frequently encountered by podiatric physicians in the hospital as well as in a clinical setting. Diabetes and prediabetes now encompass 30 percent of Americans and is considered by some to be the greatest threat to America as a whole. Type II diabetes is by and large a curable disease if diet and exercise modifications are made appropriately. To that end, it was hypothesized that vitamin D, which is available through diet and sun exposure, may have an impact on markers of diabetes, inflammation as well as wound healing. Vitamin D supplementation is a cheap and readily available supplement, which would be relatively easy for podiatric physicians to implement into their practice.

Methods: The study was a prospective randomized double-blind placebo controlled clinical trial. The study included 30 patients with grade 3 DFU. Patients were randomly divided into two groups to receive vitamin D or a placebo over a 12-week period with the vitamin D group receiving 50,000 IUs every two weeks for 12 weeks. Primary outcome measures were wound healing and insulin markers, while lipid profiles, oxidative stress and inflammatory markers were measured secondarily.

Results: Vitamin D supplementation resulted in significant reduction in ulcer length, width, depth and erythema. Vitamin D supplementation also resulted in improved insulin markers, including serum insulin, insulin resistance and HbA1c. Secondary outcome measures in the vitamin D groups were also improved, including CRP, ESR, LDL and total/HDL cholesterol ratio. There was no significant difference in diet between the two groups. As expected, the serum vitamin D levels rose significantly in the vitamin D group.

Conclusions: The hypothesis that wound healing and insulin markers would be improved with vitamin D supplementation was confirmed. Observational studies have shown vitamin D levels to be low in patients with DFU. Vitamin D supplementation may improve wound healing by many mechanisms, including reduction in hyperglycemia, which is known to disrupt cytokine production. It may also benefit wound healing by suppressing inflammation and by favorably modifying cell-mediated immune response. While a mechanism will be teased out as future research evolves, there is favorable evidence that vitamin D supplementation improves wound healing as well as glycemic control.  

The dramatic rise in diabetes and subsequent complications cannot be cured with simple supplementation of a single nutrient. However, this study shows the significant effect that a single nutrient can have on many important factors, including glucose homeostasis. A much more profound impact could be had from a well-balanced, nutrient-dense diet. Unfortunately, it is difficult to change dietary and lifestyle factors within the current health system. That being said, there is very little downside to supplementation with vitamin D for DFU patients, and it should be implemented in this population.

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