Work

Vitamin D for Painful Diabetic Neuropathy: A Systematic Review and Meta‐Analysis of Randomised Controlled Trials

Year: 2025

Type: review

Study designs: Systematic Review, Meta-Analysis

Abstract: BACKGROUND: Painful diabetic neuropathy (PDN) is a common complication of type 1 and type 2 diabetes, causing substantial morbidity. Current treatments, including antidepressants and analgesics, are often only partially effective and may have significant side effects. Vitamin D deficiency affects around 60% of people with diabetes, making supplementation a low-toxicity, biologically plausible intervention. Observational studies suggest potential benefit, but robust evidence from randomised controlled trials (RCTs) is lacking. OBJECTIVE: To systematically review and synthesise RCT evidence on the effect of vitamin D supplementation on pain outcomes in PDN. METHODS: A systematic search was conducted in Medline, EMBASE, Web of Science, Cochrane Library, CINAHL, EBSCO and Google Scholar up to September 2025. Eligible studies were RCTs comparing vitamin D supplementation with placebo in adults with diabetes and PDN. The primary outcome was pain intensity measured with validated tools. A fixed-effects meta-analysis was performed, with results expressed as standardised mean differences (SMD). Risk of bias was assessed using the Cochrane RoB tool, and publication bias examined via Egger's funnel plot. RESULTS: = 61.4%), equivalent to ~11 points on common pain scales. No studies reported medium- or long-term outcomes. Study quality varied, with concerns regarding allocation concealment and selective outcome reporting. Four trials were prospectively registered. CONCLUSION: Vitamin D supplementation may reduce short-term pain in PDN, but evidence is limited by small sample sizes and methodological quality. Larger, rigorously designed RCTs with longer follow-up are needed before routine vitamin D testing or supplementation can be recommended for PDN in clinical practice.

Source: Endocrinology Diabetes & Metabolism

DOI: 10.1002/edm2.70118

Authors: Abraham Gilbody, Joseph Gilbody

Institutions: North Bristol NHS Trust, University of Bristol, MRC Integrative Epidemiology Unit

Language: English

Topic: Vitamin D Research Studies

Subfield: Pathology and Forensic Medicine

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $3,280