Hypovitaminosis D in Painful Peripheral Neuropathy

Vitamin D is an essential vitamin necessary for maintaining proper bone structure by regulating calcium-phosphorus metabolism in the body. Vitamin D, as a hormone, also has effects on the nervous system. Peripheral neuropathy (PN) comprises a group of disorders involving the peripheral nervous system, which includes sensory, motor, and autonomic nerves. PN manifests as various symptoms, such as pain, numbness, and muscle weakness, alone or in combination. PN is caused by a wide variety of etiologies. Accumulating evidence from clinical and laboratory studies shows that hypovitaminosis-D may be a potentially independent risk factor for painful PN. Administering vitamin D to patients with hypovitaminosis-D alleviates their neuropathic symptoms. In this article, we review up-to-date clinical observations on hypovitaminosis-D