Prospective Evaluation of the Effect of Short-Term Oral Vitamin D Supplementation on Peripheral Neuropathy in Type 2 Diabetes Mellitus

Abstract

Objective: We aimed to assess the efficacy of short-term oral vitamin D supplementation on peripheral neuropathy in patients with type 2 diabetes. Materials and Methods: This prospective, placebo-controlled trial included 112 type 2 diabetic patients with diabetic peripheral neuropathy (DPN) and vitamin D [25(OH)D] deficiency. Patients were sequentially assigned to a treatment group (n = 57) and a placebo group (n = 55). DPN was assessed using a neuropathy symptom score (NSS), a neuropathy disability score (NDS) and a nerve conduction study (NCS). Vitamin D status was determined by measuring the serum total 25(OH)D concentration. Patients received either oral vitamin D₃ capsules or starch capsules once weekly for 8 weeks. The primary outcome was changes in NSS and NDS from baseline. The secondary outcome was changes in the NCS result. Results: Serum 25(OH)D concentrations significantly improved after oral vitamin D supplementation in the treatment group when compared to the placebo group (32.8 ± 23.7 vs. 1.1 ± 3.6, p < 0.0001). Similarly, the improvement in NSS values was significantly greater in the treatment group than in the placebo group (-1.49 ± 1.37 vs. -0.20 ± 0.59, p < 0.001). No improvement was observed for NDS and NCS between the 2 groups after treatment. Conclusion: Short-term oral vitamin D₃ supplementation improved vitamin D status and the symptoms of neuropathy in patients with type 2 diabetes.

The Association of Vitamin D Status and Vitamin D Replacement Therapy with Glycemic Control, Serum Uric Acid Levels, and Microalbuminuria in Patients with Type 2 Diabetes and Chronic Kidney Disease

“…This seems to support the linear relation between vitamin D deficiency and progression of MAU reported in T2DM patients [13,27] , while also emphasizing the potential benefit of the normalization of vitamin D levels in the reduction of renal and cardiovascular risks associated with MAU in these patients [12,13] .…”

“…Similar to our findings, the likely benefit of vitamin D substitution for a better T2DM prognosis was suggested in a 15-year longitudinal study among T2DM patients [26] . Clinical trials, however, have revealed inconsistent findings on the impact of maintaining adequate vitamin D status and/or high-dose vitamin replacement on long-term glycemic control in T2DM patients [14][15][16]27] . Thus, the need for validation by further large-scale, cross-sectional, and interventional clinical studies is emphasized [15] .…”

Risk Factors and Comorbidities in Diabetic Neuropathy: An Update 2015

“…Secondary risk factors are smoking and prediabetes [1,21,60,63]. Platelet activation [79][80][81][82], oxidative stress [65][66][67][68][69][70][71][72][73][74], low vitamin D [83,84], insulin resistance [58], and genetic factors [100][101][102][103][104][105][106] play another supplementary role, but, for the time being, there are limited options for intervention. A suggestion for targeting insulin resistance originates from the study by Pop-Busui et al, showing that reduced incident DSPN is less frequent in T2D patients receiving insulin-sensitizing oral agents (66%) than in those receiving insulinproviding treatment (66% vs. 72%, respectively, p = 0.02) [155].…”

“…95% CI: 1.04-11.56, p = 0.043) [83]. In a short, 8-week prospective study, the same authors demonstrated a significant (p < 0.001) improvement of neuropathic symptoms with oral vitamin D supplementation vs. placebo [84]. There is also recent evidence of a significant association between low vitamin D and impaired heart rate variability [85].…”

Exploring Factors Associated with Depression and Anxiety among Hospitalized Patients with Type 2 Diabetes Mellitus

“…Diabetes is usually accompanied by many comorbidities such as hypertension, dyslipidemia, and cardiovascular diseases [3]. Uncontrolled diabetes mellitus also leads to the development of many microvascular complications such as nephropathy, retinopathy, and neuropathy as well as macrovascular complications [4]. These complications and comorbidities, together with the emotional stress associated with the diagnosis of diabetes, had been linked to the development of depression and anxiety among diabetic patients [5,6].…”