Impact of vitamin D level in diabetic people with peripheral neuropathy

Background Diabetes mellitus (DM) is a metabolic disease which is complicated by occurrence of diabetic peripheral neuropathy (DPN). Vitamin D deficiency contributes to the etiology and progression of type 2 DM and development of micro-vascular complications so in this study we assessed vitamin D level in diabetic patients to evaluate the association between vitamin D level and occurrence of diabetic neuropathy and to assess if there is relationship with certain subtypes of diabetic neuropathy. This case–control study was conducted on 80 type 2 diabetic patients divided into four groups equally. (A): Diabetic patients with painful diabetic neuropathy. (B): Diabetic patients with painless diabetic neuropathy. (C): Diabetic patients with painless neuropathy, but have neuropathic ulcer. (D): Diabetic patients without neuropathy. All patients underwent clinical, neurological examination and nerve conduction study. Then CBC and vitamin D were estimated in the studied groups. Results Vitamin D level among the studied painful diabetic neuropathy group (A) ranged from 5.3 to 40.5 ng/dl with mean 17.4 ± 10.9. 70% of them had deficient vitamin D level. In the painless diabetic neuropathy group (B), vitamin D level ranged from 6.5 to 35.5 ng/dl with mean 18.9 ± 8.49. 60% of them had deficient vitamin D level, while only 5% of the diabetic patients without neuropathy had deficient vitamin D level. There is significant negative correlation between vitamin D level and score of neuropathy where the lower vitamin D level the higher neuropathy score. Conclusion Lower vitamin D levels were found in diabetic patients with neuropathy especially those with painful neuropathy.