Despite previous evidence showing the benefits of vitamin D supplementation in patients with fibromyalgia and chronic widespread musculoskeletal pain, controversy still exists over the role of 25OHD in the treatment of these diseases.
The symptoms and burden of pain in patients with both fibromyalgia syndrome (FMS) and chronic widespread musculoskeletal pain (CMP) were reduced for those receiving Vitamin D supplementation, according to a study published in in Nutrients.1 Results were particularly significant in those who were vitamin D deficient.
“Fibromyalgia syndrome (FMS) and chronic widespread musculoskeletal pain (CMP) are diffuse suffering syndromes that interfere with normal activities,” investigators explained. “Controversy exists over the role of vitamin D in the treatment of these diseases.”
A systematic literature review of randomized controlled trials (RCT) was used to determine whether vitamin D (25OHD) deficiency is more prevalent in CMP patients as well as evaluate the effects of vitamin D supplementation in pain management. In total, 434 studies were identified, 14 of which were ultimately included in the assessment, using data from PubMed, the Cochrane Central Register of Controlled Trials (CENTRAL), and Physiotherapy Evidence Database (PEDro) from January 1990 through July 2022.
Of the studies included, 9 RCTs assessed pain symptoms regarding vitamin D supplementation using the visual analogue scale (VAS). Three studies, 2 of which had best-quality evidence, reported a correlation between diffuse muscle pain and 25ODH deficiency. Six studies, 4 of which had best-quality evidence, reported that vitamin D supplementation was beneficial for patients with 25OHD deficiency, and 8 studies, 6 of which had best-quality evidence, showed results in pain reduction in patients receiving vitamin D.
Chronic pain was associated with lower levels of vitamin D. While 1 study showed that the correlation was confirmed in women (Heidari et al), another study (Knutsen et al) concluded that hypovitaminosis D and widespread pain was not only restricted to women. In one study, the relationship between low levels of 25OHD and pain was seen in patients regardless of other factors, such as physical activity, smoking habits, and alcohol use, when comparing patients with FMS and healthy controls (23.9 ng/mL vs. 25.6 ng/mL; p = 0.05). 25OHD may also play a role in etiology of chronic pain conditions such as headaches or abdominal pain. Investigators reported that the severity of pain and lack of treatment often lead to self-medication.
There was a “high risk” of bias in 6 of the studies, a “low risk in 6, and “some concerns” in 2 studies. The most notable source of high risk was the “selection of the reported result,” presented in 3 studies (23% of the cases).
“The therapeutic approach to FMS and CMP necessarily involves a multidisciplinary protocol, which should be conducted as a team because of the many facets of the pathologies and the many compromised systems,” investigators concluded. “This review suggests that vitamin D deficiency is frequently observed in FMS and CMP patients, and supplementation with vitamin D can be proposed to reduce musculoskeletal pain and improve the quality of life in vitamin D-deficient subjects with FMS and CMP.”
Lombardo M, Feraco A, Ottaviani M, et al. The Efficacy of Vitamin D Supplementation in the Treatment of Fibromyalgia Syndrome and Chronic Musculoskeletal Pain. Nutrients. 2022;14(15):3010. Published 2022 Jul 22. doi:10.3390/nu14153010