Vitamin D supplementation reduces infection rate and promotes wound healing in patients with diabetic foot ulcers.

BACKGROUND: Diabetic foot ulcers (DFUs) represent a common and serious complication of diabetes, characterized by impaired wound healing and an increased risk of infection. These infections severely impact patient health, necessitating extensive medical intervention, and increasing the risk of amputation. Vitamin D (VD) plays a critical role in immune regulation and tissue repair. AIM: To investigate the effects of VD supplementation on infection rates, wound healing, and immune function in patients with DFUs. METHODS: A randomized controlled trial was conducted involving 120 patients with DFUs. Participants were randomly assigned to either a control group (= 60), which received standard care without VD supplementation, or an intervention group (= 60), which received 2000 IU of oral VD3 (cholecalciferol) daily for 12 weeks. The primary outcomes included the incidence and severity of infections, whereas the secondary outcomes included wound healing rate, serum 25-hydroxyvitamin D level, levels of immune markers (cathelicidin, interleukin-6 and tumor necrosis factor-α), and adverse events, such as hypercalcemia. RESULTS: The incidence of infection was significantly lower in the VD supplementation group (25%) compared with the control group (45%) (= 0.01). Severe infections requiring systemic antibiotics or hospitalization were also less frequent in the VD supplementation group. Wound healing was notably enhanced in the VD supplementation group, with a 60% reduction in ulcer size compared with a 35% reduction in the control group (< 0.01). Serum 25(OH)D level significantly increased in the VD supplementation group (from 16.5 ng/mL to 35.2 ng/mL), confirming the efficacy of VD supplementation. Immune function improved, as demonstrated by a 30% rise in cathelicidin level and a 20% decline in levels of pro-inflammatory cytokines. No adverse effects, including hypercalcemia, were reported. CONCLUSION: The VD supplementation effectively reduced infection rate, promoted wound healing, and strengthened immune responses in patients with DFUs. These findings support the incorporation of VD as a safe and effective adjunctive therapy in the clinical management of DFUs.