Vitamin D Deficiency Linked to Painful Diabetic Neuropathy

Sarfaroj Khan 

June 16, 2020


  • This study suggests that vitamin D deficiency (<20 ng/mL) and insufficiency (<30 ng/mL) are associated with an increased risk of painful diabetic neuropathy (PDN).

Why this matters

  • Findings warrant a well-constructed clinical trial of vitamin D in PDN to assess the effectiveness of a potentially simple treatment with no obvious side effects.

Study design

  • This study included 43 patients with type 1 diabetes (painless diabetic peripheral neuropathy [DPN; n=20] or PDN [n=23]) and 14 matched non-diabetic control participants.

  • Funding: Juvenile Diabetes Research Foundation and the National Institutes of Health.

Key results

  • No significant differences were seen for age, body mass index, haemoglobin A1c, lipids, neurological deficits, quantitative sensory testing, electrophysiology, intra-epidermal nerve fibre density and corneal confocal microscopy between the DPN and PDN groups.

  • Both positive (P=.009) and negative (P=.02) symptoms of diabetic neuropathy were significantly greater in patients with PDN vs. those with DPN.

  • McGill pain score and Visual Analogue Score were significantly greater in PDN vs DPN and controls (P<.0001 for both).

  • Neuropathy symptom profile was significantly higher in PDN vs DPN (P<.0005) and controls (P<.0001).

  • Serum 25(OH)D levels were significantly reduced in PDN (24.0±14.1 ng/mL) vs DPN (34.6±15.0 ng/mL; P=.01) and controls (34.1±8.6 ng/mL; P=.03).

  • Vitamin D deficiency (OR, 9.8; 95% CI, 2.2-76.4; P=.003) and insufficiency (OR, 4.4; 95% CI, 1.1-19.8; P=.03) were associated with an increased risk of PDN.


  • Small sample size.

  • Lack of quantification of sunlight exposure or daily activity and comparison with a non-neuropathic diabetic cohort.

Alam U, Petropoulos IN, Ponirakis G, Ferdousi M, Asghar O, Jeziorska M, Marshall A, Boulton AJ, Efron N, Malik RA. Vitamin D Deficiency is Associated With Painful Diabetic Neuropathy. Diabetes Metab. Res. Rev.2020 Jun 07 [Epub ahead of print]:e3361. doi: 10.1002/dmrr.3361. PMID: 32506740.  Abstract.

This clinical summary first appeared on Univadis, part of the Medscape Professional Network.


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