- This study suggests that vitamin D deficiency (
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.
- 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.
- 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>
- 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.