Vitamin and mineral status in chronic fatigue syndrome and fibromyalgia syndrome: A systematic review and meta-analysis.

Abstract

BACKGROUND: Many chronic fatigue syndrome (CFS) and fibromyalgia syndrome (FMS) patients (35-68%) use nutritional supplements, while it is unclear whether  deficiencies in vitamins and minerals contribute to symptoms in these patients.  Objectives were (1) to determine vitamin and mineral status in CFS and FMS  patients as compared to healthy controls; (2) to investigate the association  between vitamin and mineral status and clinical parameters, including symptom  severity and quality of life; and (3) to determine the effect of supplementation  on clinical parameters. METHODS: The databases PubMed, EMBASE, Web of Knowledge,  and PsycINFO were searched for eligible studies. Articles published from January  1st 1994 for CFS patients and 1990 for FMS patients till March 1st 2017 were  included. Articles were included if the status of one or more vitamins or  minerals were reported, or an intervention concerning vitamins or minerals was  performed. Two reviewers independently extracted data and assessed the risk of  bias. RESULTS: A total of 5 RCTs and 40 observational studies were included in  the qualitative synthesis, of which 27 studies were included in the  meta-analyses. Circulating concentrations of vitamin E were lower in patients  compared to controls (pooled standardized mean difference (SMD): -1.57, 95%CI:  -3.09, -0.05; p = .042). However, this difference was not present when  restricting the analyses to the subgroup of studies with high quality scores.  Poor study quality and a substantial heterogeneity in most studies was found. No  vitamins or minerals have been repeatedly or consistently linked to clinical  parameters. In addition, RCTs testing supplements containing these vitamins  and/or minerals did not result in clinical improvements. DISCUSSION: Little  evidence was found to support the hypothesis that vitamin and mineral  deficiencies play a role in the pathophysiology of CFS and FMS, and that the use  of supplements is effective in these patients. REGISTRATION: Study methods were  documented in an international prospective register of systematic reviews  (PROSPERO) protocol, registration number:  http://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42015032528.