The role of vitamin D in pathophysiology and treatment of fibromyalgia.

Recent studies showed that most cells have receptors and enzymes responsible for metabolism of vitamin D. Several diseases have been linked to vitamin D deficiency, such as hypertension, diabetes, depression, Alzheimer's disease, Parkinson's disease, multiple sclerosis, and chronic pain syndromes such as fibromyalgia. The association between fibromyalgia and vitamin D deficiency is very controversial in the literature with conflicting studies and methodological problems, which leads to more questions than answers. The purpose of this article is to raise questions about the association of hypovitaminosis D with fibromyalgia considering causal relationships, treatment, and pathophysiological explanations.