Br J Nutr. 2021 May 24;1-35. doi: 10.1017/S0007114521001707
Kaissar Yammine 1 2 3, Joelle Abi Kharma 4, Theodore Kaypekian 5, Chahine Assi 1 3, Nadine Zeeni 4
Several studies have been conducted to investigate the relation between 25-hydroxyvitamin D [25(OH)D] level and diabetic neuropathy (DN). However, there is still no clear conclusion due to differences in study design and cut-off values used in the published work, in addition to the absence of a comprehensive meta-analysis on the topic. The present systematic review and meta-analysis therefore aims at clarifying the association between vitamin D level and peripheral DN in patients with type 2 diabetes mellitus.Primary research studies that explored the association between 25(OH)D level and diabetic peripheral neuropathy in type 2 diabetes were located from Medline, EMBASE, Web of Science, Cochrane Library, CINHAL, and Google Scholar. Twenty-six studies met the inclusion criteria with 6277 participants where 2218 were diabetic with DN, 2959 were diabetic without DN and 406 were healthy. Diabetic patients with DN showed significantly lower serum 25(OH)D compared to patients without DN (standardized mean difference (SMD) of -0.92 (95% CI = -1.18 to -0.65, I2 = 93.3%, p < 0.0001).
The pooled OR value of vitamin D deficiency was higher in patients with DN,
- 1.84 (95% CI = 1.46 to 2.33, p < 0.0001) and
- 2.87 (95% CI = 1.10 to 7.52, p = 0.03)
when using fixed-effects and random-effects models, respectively.
Vitamin D deficiency has been found to be highly prevalent among diabetic patients with neuropathy. Since 25(OH)D has been implicated in glucose hemostasis and showed benefit in reducing neuropathy symptoms, its supplementation is warranted for this population of patients.