Vitamin D-deficient fibromyalgia patients may benefit both physically and psychologically from vitamin D supplements combined with an antidepressant, according to researchers.
Vitamin D is essential for maintaining the function of the musculoskeletal system, and low levels of this compound have long been proposed to be linked to chronic widespread pain, the primary symptom of fibromyalgia.
But there is still no consensus about the association between vitamin D and fibromyalgia. Various studies have demonstrated a positive correlation between low vitamin D levels and nonspecific musculoskeletal pains, while others admit no association at all between fibromyalgia and vitamin D.
“To the best of our knowledge, only one published randomized controlled trial is available on the role of vitamin D in the [disease process] of fibromyalgia, which indicates the efficacy of 25-hydroxy vitamin D optimization in [the] reduction of pain and morning fatigue symptoms of the affected patients,” researchers from the Iran University of Medical Sciences wrote.
Because fibromyalgia is a disease with both physical and psychological symptoms, scientists hypothesized that vitamin D supplements combined with a low-dose antidepressant could improve some symptoms.
The parallel, randomized, double-blind, and placebo-controlled trial included 74 patients who were randomly assigned to receive either a trazodone 25 mg tablet every day at bedtime plus oral vitamin D 50,000 IU a week, or trazodone 25 mg daily at bedtime and a placebo (without the vitamin) for eight weeks.
Researchers used the Widespread Pain Index (WPI) to register the body areas where patients felt pain in the last week before their medical assessment; the Fibromyalgia Impact Questionnaire (FIQ) to measure arthritis symptoms and functional status; the Pittsburgh Sleep Quality Index (PSQI) to assess the quality and patterns of sleep over the previous month; and the Short Form Health Survey (SF-36) to generically measure quality of life.
Patients were evaluated at the beginning of the study and at weeks four and eight after treatment began.
“Among 74 patients, 10 (13.5%) were identified with vitamin D insufficiency and 64 (86.5%) with vitamin D deficiency,” researchers reported.
The combination therapy was found to significantly reduce the perception of pain in both treatment groups, but improvements were more obvious in the vitamin D-trazodone arm.
Significant improvements in disease symptoms, including pain, fatigue, morning tiredness, stiffness, anxiety, and depression, were also observed in the experimental group compared to the control group.
Sleep quality was also improved in both groups, which could be related to the antidepressant’s pharmacological effect of inducing restful sleep.
Of note, the combination of vitamin D supplements and trazodone significantly improved patients’ quality of life, both physically and mentally, compared to the control group.
This study showed that vitamin D supplements are a safe and cheap treatment option that seems to improve the quality of life in fibromyalgia patients.
Using an antidepressant together with a vitamin D supplement shows promise as a management therapy of fibromyalgia’s physical and psychological symptoms.
“Similar studies with longer follow-up periods in future investigations will further explore the impact of vitamin D optimization in the quality of life of fibromyalgia patients,” the researchers wrote.