Vitamin D, Magnesium Deficiency Linked to Worse Fibromyalgia Symptoms

Maria Grazia Tarsitano, MD, PhD

Credit: UniCamillus

An exploratory study evaluating the link between specific micronutrients and the symptoms of fibromyalgia revealed vitamin D and magnesium played a role in physical function and stiffness among patients.¹

Fibromyalgia, a condition more commonly diagnosed in women, is characterized by chronic generalized musculoskeletal pain. Symptoms can also present as sleep disorders, cognitive impairment, depression, fatigue, migraine, psychological manifestations, restless legs syndrome, and irritable bowel syndrome. Although the etiology is not completely understood, biological factors, lifestyle behaviors, and physical and emotional stressors have been linked to fibromyalgia.²

“The management of fibromyalgia requires a multidisciplinary approach that combines pharmacological and non-pharmacological strategies,” wrote a group of investigators led by Maria Grazia Tarsitano, MD, PhD, of the Department of Medical and Surgical Sciences, Magna Graecia University, Catanzaro, Italy. “Growing evidence suggests a potential beneficial role of micronutrients such as minerals and vitamins. Overall, the role of these supplements remains controversial, but clinical trials on vitamin D, vitamin B12, magnesium, and iron supplementation seem to provide promising results.”

The cross-sectional study assessed the role of micronutrients among a cohort of 20 Italian women with fibromyalgia using the Fibromyalgia Impact Questionnaire (FIQ). A group of 20 age-matched women with no chronic disease, pain, or fibromyalgia were recruited as a control group. Information on age, body mass index, disease duration, and blood levels of vitamin D, vitamin B12, iron, magnesium, and ferritin were collected. Fibromyalgia cases were identified according to the American College of Rheumatology (ACR)/European Alliance of Associations for Rheumatology (EULAR) diagnostic criteria. The FIQ assessed a patient’s ability to perform daily tasks, such as walking and cooking, the impact of fibromyalgia on a patient’s ability to work, and physical impairment.

Investigators also performed a literature review of PubMed and Scopus databases. Eligible studies were published within the last 10 years, written in English, and contained the keywords “fibromyalgia” AND “vitamin D,” “magnesium,” “vitamin B12,” “iron,” or “ferritin.”

Among the patients with fibromyalgia, there was a moderate negative correlation between vitamin D and physical functioning (r = -.561, P = .008) as well as between magnesium and stiffness (r = -.518, P = .016).

Approximately 40% of patients enrolled were vitamin D deficient. Previous research has shown reduced vitamin D levels are linked to depression, anxiety, and chronic pain in patients with fibromyalgia. Investigators identified several studies evaluating this connection, one of which showed significant improvement in symptoms after 8 weeks of 50,000 weekly units of vitamin D3. Other studies also showed similar beneficial effects in smaller sample sizes.

Magnesium deficiency can cause low-grade inflammation and muscle weakness and is linked to a worse pain threshold. Despite this, investigators could only identify 2 clinical studies evaluating this micronutrient for the treatment of fibromyalgia. In the first study, magnesium had little to no effect on pain or depression in a group of 24 women with fibromyalgia. The second study showed amitriptyline and concomitant magnesium supplementation was more effective than amitriptyline alone in 60 female patients. However, as magnesium deficiency is linked to pain intensity, supplementing with the micronutrient could be helpful in the management of symptoms.

Investigators noted the small sample size as the main limitation of the study.

“Screening for micronutrient deficiencies in fibromyalgia patients is useful in clinical practice,” investigators concluded. “Supplementation in patients – even when not deficient – should be considered due to the inverse association between vitamin D and magnesium levels and physical function/stiffness. Further studies are needed to make solid recommendations.”

References

1. ^{Tarsitano MG, Dolcini G, Pandozzi C, et al. Role of micronutrients in the symptoms of fibromyalgia: a review of the literature and analysis of an Italian female sample. Eur Rev Med Pharmacol Sci. 2024;28(14):4038-4045. doi:10.26355/eurrev_202407_36579}
2. ^{Creed F. A review of the incidence and risk factors for fibromyalgia and chronic widespread pain in population-based studies. Pain 2020; 6: 1169-1176.}