Research appearing in the July 19, 2006 issue of Clinical Rheumatology, linked anxiety and depression experienced by fibromyalgia patients to vitamin D levels. The subjects of the study were 75 patients with fibromyalgia who filled out a Fibromyalgia Impact Questionnaire and Hospital Anxiety and Depression Score. Blood samples were taken to measure vitamin D levels. Twenty-three of the patients had normal levels of vitamin D. Ten of the patients were deficient in vitamin D and 42 had insufficient levels. Patients who were deficient in vitamin D placed higher on the Hospital Anxiety and Depression Score than those with normal or insufficient levels of vitamin D. The researchers concluded that low vitamin D levels were associated with fibromyalgia and that the anxiety and depression associated with the disease may be linked to low vitamin D levels.