Diabet. Med. 29, 50–55 (2012)
Aims To evaluate the association between vitamin D insufficiency and peripheral neuropathy in a nationally representative sample of adults with diagnosed diabetes.
Methods Vitamin D concentrations, medical examination variables and questionnaire results from the 2001–2004 National Health and Nutrition Examination Survey were analysed for adults ≥ 40 years old with diagnosed diabetes (unweighted n = 591, weighted n = 8.82 million). Neuropathy was defined as self report of peripheral neuropathy symptoms of painful sensation, tingling, numbness or loss of feeling in hands or feet. Additionally, Semmes–Weinstein monofilament test results were used as an indicator of neuropathy. Insufficient vitamin D was characterized as < 30 ng/ml.
Results In the weighted population, 81% of adults with diabetes had vitamin D insufficiency. Vitamin D insufficiency was more common among Hispanics (92%) and non-Hispanic black people (98%) than among non-Hispanic white people (76%). Within the 3 months preceding the questionnaire, 50% reported experiencing pain or numbness (paresthesia) in their hands or feet; 37% reported pain or tingling in hands or feet; and 38% reported numbness or loss of feeling in hands or feet. Eight per cent had 4–6 insensate areas on their feet as determined by the Semmes–Weinstein monofilament test. Logistic regressions demonstrate vitamin D insufficiency is associated with the adjusted composite paresthesia measure (odds ratio 2.12; 95% CI 1.17–3.85) and the adjusted numbness measure (odds ratio 2.04; 95% CI 1.18–3.52).
Conclusions Vitamin D insufficiency is associated with self-reported peripheral neuropathy symptoms even after adjusting for demographic factors, obesity, co-morbidities, use of medications for neuropathy and diabetes duration and control.