The Effect of Vitamin D Supplementation on Treatment-Induced Pain in Cancer Patients: A Systematic Review.

ABSTRACT

OBJECTIVES: Despite the widespread use of complementary and alternative medicine by patients and physicians alike, there is no accurate evidence regarding the effects of vitamin D supplementation on treatment-induced pain in cancer patients. Thus, the aim of this systematic review of randomized controlled trials (RCTs) was to evaluate the impact of vitamin D administration on therapy-related pain in subjects diagnosed with malignant disorders. REVIEW ANALYSIS METHODS: We searched the Web of Science, Scopus, PubMed/Medline, Embase, and Google Scholar databases up to October 2020 to identify published RCTs that investigated the use of vitamin D in the management of treatment-induced pain in individuals with cancer. RESULTS: Nine RCTs were detected. The median duration of the intervention was of 24 weeks (range 12-52 weeks) and dose of vitamin D employed was 2000-50000 IU of vitamin D3 weekly orally each day. Six RCTs reported a significant reduction in pain, whereas three did not detect a notable decrease of this variable. Of the six studies that reported an alleviation of pain, an RCT which recruited 60 participants and lasted for 24 weeks consisted of supplementation with high doses of vitamin D2 weekly for 8 weeks in women receiving anastrozole as adjuvant therapy, then supplementation with vitamin D2 monthly for 4 months, effectively alleviated the aromatase inhibitor-associated musculoskeletal syndrome (AIMSS). The results of the same RCT also suggested a beneficial effect of vitamin D on musculoskeletal pain. CONCLUSIONS: Our results suggest that the supplementation with high doses of vitamin D in cancer patients with low serum levels of vitamin D, can be effective in reducing treatment-related pain.