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Not yet recruiting NCT07644520

Vitamin D in Diabetic Neuropathy

Phase II / Phase III Interventional Diabetic Nephropathy Type 2

For patients and families

In plain language

An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.

What is being studied
The protocol lists: Vitamin D.
Who it may be relevant to
Registry conditions: Diabetic Nephropathy Type 2. Basic parameters: 18 years — 65 years · All.
What needs checking
Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
Where it takes place
Center list to be confirmed — check the primary protocol.
Next step
Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →

Unsure about the terms? Read our patient guide →

Official title

Effect of Vitamin D Supplementation on Neuropathic Pain, Sleep Quality, and Quality of Life in Patients With Diabetic Peripheral Neuropathy

Overview

Introduction Diabetic peripheral neuropathy (DPN) is among the most common chronic complications of diabetes mellitus and represents a major cause of morbidity, impaired quality of life, sleep disturbance, chronic pain, and functional disability.(Kurz et al., 2026) The pathogenesis of DPN is multifactorial and involves oxidative stress, chronic inflammation, endothelial dysfunction, mitochondrial injury, and microvascular ischemia, leading to progressive nerve damage.(Yang et al., 2025) Despite the availability of symptomatic therapies such as gabapentin, pregabalin, and duloxetine, many patients continue to experience persistent neuropathic symptoms, poor sleep quality, and impaired daily functioning. Existing pharmacological therapies are often associated with incomplete response, adverse effects, and high economic burden.(Kaye et al., 2025) Recently, vitamin D has attracted attention beyond its classical role in calcium and bone metabolism. Experimental and clinical evidence suggest that vitamin D possesses neuroprotective, anti-inflammatory, immunomodulatory, and antioxidative properties. Vitamin D receptors are widely distributed in neuronal tissues, Schwann cells, and immune cells, suggesting a potential role in nerve repair and modulation of neuropathic pain pathways.(Liu et al., 2025) Several observational studies have demonstrated a high prevalence of vitamin D deficiency among patients with diabetic neuropathy, and low serum vitamin D levels have been associated with increased neuropathic pain severity and poorer quality of life. However, available interventional studies remain limited and have produced inconsistent findings regarding the therapeutic benefit of vitamin D supplementation in DPN.(Ou et al., 2021) Therefore, this study aims to evaluate whether vitamin D supplementation can improve neuropathic pain, sleep quality, and health-related quality of life among patients with diabetic peripheral neuropathy.

Interventions

  • Dietary supplement Vitamin D
    VITAMIN D SUPPLEMENT

Primary outcome measures

  • Primary outcome Change in neuropathic pain severity Measured using Visual Analog Scale (Baseline -Week 6 -Week 12) [Time frame: 3 months]

Eligibility criteria

Inclusion criteria

Participants must fulfill all the following:

1\. Age between 18 and 75 years 2. Diagnosed with type 2 diabetes mellitus according to ADA criteria 3. Clinically diagnosed diabetic peripheral neuropathy 4. Neuropathic symptoms for at least 3 months 5. Vitamin D insufficiency or deficiency:

  • Serum 25(OH)D < 30 ng/mL 6. Stable antidiabetic treatment for at least 3 months Exclusion criteria
  • Type 1 diabetes mellitus
  • Current vitamin D supplementation within the previous 3 months
  • Severe renal impairment (eGFR < 30 mL/min/1.73m²)
  • Severe hepatic impairment
  • Hypercalcemia
  • Malabsorption syndromes
  • Pregnancy or lactation
  • Peripheral neuropathy due to causes other than diabetes:
  • Vitamin B12 deficiency
  • Hypothyroidism
  • Alcoholic neuropathy
  • Chemotherapy-induced neuropathy 9. Active malignancy 10. Severe psychiatric illness

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation
Randomized
Model
Parallel assignment
Masking
Open label
Primary purpose
Treatment

Study locations

Center list to be confirmed — check the primary protocol.

Identifiers

NCT: NCT07644520 · Vitamin D in DNP

Primary sources (government registries)

View this study on ClinicalTrials.gov ↗