Israel Medical Association Journal

Background: Vitamin D deficiency and insufficiency have been reported in fibromyalgia. However, to the best of our knowledge, only one study has evaluated the role of 25-hydroxyvitamin D [25(OH)D] supplementation on fibromyalgia symptoms.

Objectives: To analyze the effects of 3 months of 25(OH)D supplementation on symptoms of fibromyalgia.

Methods: This study included 11 female patient. Demographic and clinical data, tender points, visual analog scale results, and pre- and post-serum levels of 25(OH)D supplementation were analyzed. The levels of 25(OH)D were measured by a radioimmunologic test.

Results: Patients with fibromyalgia diagnosis and 25(OH)D values ≤ 30 ng/ml were recruited to receive 50,000 IU of oral vitamin D once every week for 3 months. The disease was diagnosed based on the American College of Rheumatology criteria. The median age of all patients was 48.5 (28–67) years and 63.4% were Caucasian. Disease duration varied from 1–10 years. The 25(OH)D levels increased significantly after 3 months, 18.4 (15.5–25.8) ng/ml vs. 33.8 (28–58) ng/ml, P = 0.01. Interestingly, an improvement of visual analog scale scores was observed at 3 months, 90 (0–100) vs. 30 (0–80), P = 0.002. Eight patients (72.2%) responded that they experienced a very significant improvement in symptoms. In addition, a trend for reduction of the number of tender points was observed after 3 months, 17 (11–18) vs. 10 (0–18), P = 0.07.

Conclusions: The 25(OH)D levels and disease symptoms in patients with fibromyalgia and vitamin D deficiency/insufficiency seem to improve with vitamin D supplementation.

Vitamin D deficiency is becoming an increasing problem worldwide. It should not be underestimated, not only due to the well-known consequences vitamin D deficiency has on bone health, but primarily because recent studies have shown how the biologically active form of vitamin D – 1,25(OH)2D – is involved in many biological processes, including immune system modulation. Moreover, the presence of a vitamin D receptor was discovered in almost all immune cells and some of its polymorphisms were found to be associated with increased incidence of autoimmune diseases. This finding led to a proposed link between vitamin D deficiency and autoimmune diseases. Patients affected by various autoimmune diseases showed low levels of vitamin D. However, it is not always clear whether vitamin D deficiency is the cause or rather a consequence of the disease. Limitations of the studies, such as the small number of patients, heterogeneity of selected groups, environmental conditions, methods used to measure vitamin D serum concentration and other confounding factors do not lead to unequivocal results to demonstrate a direct link between low vitamin D levels and autoimmune disease. Therefore, randomized trials are needed to clarify conflicting results.

Background: Israel is a country with a sunny climate; however, vitamin D deficiency and insufficiency are common findings in certain populations whose exposure to sunlight is limited. Medical residency is known for long indoor working hours, thus theoretically limiting the opportunities for sun exposure.

Objectives: To evaluate whether the vitamin D status among residents in a single medical center in Tel Aviv is below the normal range.

Methods: Forty-six residents (28 females, 18 males, average age 33.9 ± 2.8 years) in three residency programs (internal medicine, general surgery/obstetrics and gynecology, pediatrics) were recruited. Demographic data, personal lifestyle, physical activity details and sun exposure duration were obtained by a questionnaire. Serum levels for 25(OH)D were analyzed by a radioimmunoassay.

Results: The mean serum 25(OH)D concentration was 29.8 ± 5.8 ng/ml. According to Institute of Medicine definitions, none of the residents were vitamin D deficient and only two residents (4%) were vitamin D insufficient (15 ng/ml each). The level of 25(OH)D was similar among the various medical specialties. The 25(OH)D levels correlated with the duration of sun exposure and the number of offspring (regression analysis: R2 = 9.2%, P < 0.04 and R2 = 8.9%, P < 0.04, respectively), but not with nutritional data, blood chemistry, or extent of physical activity. 

Conclusions: Most of the residents maintained normal or near normal 25(OH)D levels, indicating that the residency program itself did not pose a significant risk for vitamin D deficiency.