Vitamin D Deficiency and Chronic Widespread Pain

Abstract

Vitamin D acts as a steroid hormone possessing important functions in calcium and phosphorus balance and bone health. The presence of vitamin D receptors (VDRs) in many tissues in the human body shows that this vitamin might have effects other than its role in maintaining bone health. Hence, many studies in the last two decades have reported an association between vitamin D deficiency and many musculoskeletal and extra-skeletal diseases. Despite the presence of clear evidence suggesting a causative relationship between musculoskeletal pain and osteomalacia developing as a result of long-term and severe vitamin D deficiency, a putative relationship between vitamin D deficiency and chronic widespread pain (CWP) has recently been an exciting area of discussion. The hypothetical role of vitamin D in the pathophysiology of pain, the availability of VDRs in the muscle tissue and central nervous system, particularly in the hypothalamus, and the reports on the development of muscle hypersensitivity associated with vitamin D deficiency, have provided a basis for a putative relationship between CWP and vitamin D status. This review will discuss these two problems that commonly occur within the general population, and endeavour to reveal this relationship in light of currently available studies.