Vitamin D in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome After COVID-19 or Vaccination: A Randomized Controlled Trial

Abstract:

Background: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) can develop as post-vaccination syndrome (PVS) or Post-Acute Sequelae of SARS-CoV-2 infection (PASC). In our prior retrospective study, most patients with PVS who developed ME/CFS had vitamin D insufficiency or deficiency. We evaluated the efficacy of vitamin D replacement therapy guidance for ME/CFS symptom improvement in patients with vitamin D insufficiency or deficiency.

Methods: This open-label randomized controlled trial enrolled 91 participants with ME/CFS as PVS or PASC and serum 25(OH) vitamin D < 30 ng/mL across five clinical sites. Participants were randomized 1:1 to intervention (active vitamin D preparation plus vitamin D replacement therapy guidance: 25 μg daily supplementation, dietary counseling, sun exposure, and exercise) or control (active vitamin D preparation alone) for 12 weeks. The primary endpoint was the change in ME/CFS symptom count from screening to Week 12.

Results: Mean symptom change was -6.7 in the intervention group versus -1.2 in the control group (between-group difference -5.6; 95% CI: -7.2, -3.9; p < 0.001). Serum 25(OH) vitamin D improved from 18.6 to 27.1 ng/mL in the intervention group, while the control group showed a decreasing trend (between-group difference 10.2 ng/mL; 95% CI: 7.9, 12.5). Achievement of <8 symptoms (i.e., no longer meeting ME/CFS diagnostic criteria) was significantly higher in the intervention group, with 16 participants achieving this threshold compared to 1 in the control group (p < 0.001). Subgroup analyses showed consistent benefit in both PVS (n = 56) and PASC (n = 29) cohorts.

Conclusions: Vitamin D replacement therapy guidance significantly reduced ME/CFS symptoms along with improvement of serum 25(OH) vitamin D levels in patients with vitamin D insufficiency or deficiency who developed ME/CFS as PVS or PASC.

Source: Kodama S, Nakata M, Konishi N, Yoshino M, Fujisawa A, Naganuma M, Kobayashi Y, Hirai Y, Kitagawa A, Miyokawa M, Mishima R, Teramukai S, Fukushima M. Vitamin D in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome After COVID-19 or Vaccination: A Randomized Controlled Trial. Nutrients. 2026 Feb 3;18(3):521. doi: 10.3390/nu18030521. PMID: 41683343. https://www.mdpi.com/2072-6643/18/3/521 (Full text)

Potential application of brain-gut axis-based treatments in Long COVID and ME/CFS: a case-based systematic review

Abstract:

Background: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and Long COVID share clinical features including persistent fatigue, post-exertional malaise (PEM), and gastrointestinal (GI) dysfunction. Growing evidence implicates brain-gut axis dysregulation, characterized by dysbiosis, neuroinflammation within the central nervous system (CNS), increased intestinal permeability, and microbial translocation in their pathophysiology. However, therapeutic strategies targeting these pathways remain poorly defined.

Methods: We report a case of post-COVID ME/CFS successfully treated with electroacupuncture (EA)-based deep peroneal nerve stimulation which was employed to potentiate the vagal reflex. Fatigue trajectories were assessed using the Multidimensional Fatigue Inventory over 12 weeks. Based on the case, a systematic review of randomized controlled trials (RCTs) evaluating brain-gut axis-modulating interventions in ME/CFS or Long COVID was conducted.

Results: The patient exhibited a significant reduction in total fatigue, with early improvements in motivation and mental fatigue, and delayed improvement in physical fatigue following transient systemic symptom flares. Across included RCTs (n = 8, 790 participants), four investigated gut microbiome-modulating therapies and four employed nerve stimulation. Synbiotic and herbal interventions demonstrated benefits for fatigue or PEM, accompanied by alterations in specific bacterial populations or CNS metabolisms. Regarding nerve stimulation, transcranial direct current stimulation (tDCS) combined with exercise program improved fatigue, whereas standalone tDCS, auricular or peripheral TENS showed limited efficacy.

Conclusion: Brain-gut axis-based interventions may alleviate fatigue in ME/CFS and Long COVID by potentially modulating neuroinflammation, restoring microbiome balance, and improving epithelial barrier function. EA-based vagal stimulation represents a feasible option for patients with severe or treatment-resistant symptoms. Larger mechanistic studies and rigorously designed RCTs are needed to establish therapeutic targets and optimize intervention strategies.

Source: Kim DY, Youn J, Kang N, Cho SI, Ha IH. Potential application of brain-gut axis-based treatments in Long COVID and ME/CFS: a case-based systematic review. J Transl Med. 2026 Feb 10. doi: 10.1186/s12967-026-07807-w. Epub ahead of print. PMID: 41668172. https://link.springer.com/article/10.1186/s12967-026-07807-w (Full text available as PDF file)

No consistent evidence for the anti-inflammatory effect of vagus nerve stimulation in humans: A systematic review and meta-analysis

Abstract

Vagus nerve stimulation (VNS) has been identified as an innovative immunosuppressive treatment strategy in rodent studies. However, its’ clinical potential is still unclear. Therefore, we aimed to assess whether VNS can reduce inflammatory proteins and/or immune cells in humans, through a pre-registered systematic review and meta-analysis according to PRISMA guidelines. The databases Cochrane, Pubmed and World of Knowledge were searched in duplicate up to the 3rd of March 2022 and publications from identified clinical trial registrations were identified until 20th of August 2023. Studies were included if they provided peer-reviewed data for humans who received VNS as short-term (<=1 day) or long-term (>=2 days-365 days) stimulation and reported at least one cytokine or immune cell after treatment.

Screening of title, abstract, full text, and data extraction was performed in duplicate by two independent reviewers. Data were pooled using a random-effects model and meta-regression was performed for moderating factors. Reporting bias was assessed. The standardized mean difference (Hedge’s g) was used to indicate overall differences of cytokine data (mean and standard deviation or median and interquartile range at the study level) to test our a-priori hypothesis.

The systematic review of 36 studies with 1135 participants (355 receiving a control/sham condition and 780 receiving VNS) revealed anti-inflammatory effects of VNS for cytokines in several reports, albeit often in subgroup analyses, but our meta-analyses of 26 studies did not confirm these findings. Although most cytokines were numerically reduced, the reduction did not reach statistical significance after VNS: not in the between-group comparisons (short-term: TNF-α: g = -0.21, p = 0.359; IL-6: g = -0.94, p = 0.112; long-term: TNF-α: g = -0.13, p = 0.196; IL-6: g = -0.67, p = 0.306); nor in the within-study designs (short-term: TNF-α: g = -0.45, p = 0.630; IL-6: g = 0.28, p = 0.840; TNF-α: g = -0.53, p = 0.297; IL-6:g = -0.02, p = 0.954). Only the subgroup analysis of 4 long-term studies with acute inflammation was significant: VNS decreased CRP significantly more than sham stimulation. Additional subgroup analyses including stimulation duration, stimulation method (invasive/non-invasive), immune stimulation, and study quality did not alter results. However, heterogeneity was high, and most studies had poor to fair quality. Given the low number of studies for each disease, a disease-specific analysis was not possible.

In conclusion, while numeric effects were reported in individual studies, the current evidence does not substantiate the claim that VNS impacts inflammatory cytokines in humans. However, it may be beneficial during acute inflammatory events. To assess its full potential, high-quality studies and technological advances are required.

Source: Schiweck C, Sausmekat S, Zhao T, Jacobsen L, Reif A, Edwin Thanarajah S. No consistent evidence for the anti-inflammatory effect of vagus nerve stimulation in humans: A systematic review and meta-analysis. Brain Behav Immun. 2024 Feb;116:237-258. doi: 10.1016/j.bbi.2023.12.008. Epub 2023 Dec 7. PMID: 38070618. https://www.sciencedirect.com/science/article/abs/pii/S0889159123003793

From tradition to healing: the promise of acupuncture in managing chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) is a global public health problem affecting more than 65 million patients worldwide. The combined prevalence rate of CFS was 45.2% after 4 weeks in patients with novel coronavirus. Women, people over 40 years of age, and low-income people are susceptible groups, which have a significant impact on immune, nervous, endocrine, and other system functions.

First, from the perspective of epidemiology, this paper reviews the global epidemic trend of CFS, the differences in incidence and prevalence in different regions and populations, and risk factors such as heredity, infection, and childhood trauma. Second, the development of diagnostic techniques for CFS, including the evolution of clinical diagnostic criteria, research progress on immune and metabolic biomarkers, and the application of MRI and other imaging techniques in the diagnosis of CFS, is described, followed by an in-depth discussion of the genetics of CFS, including genetic susceptibility, genomic association, and familial aggregation. The pathophysiological mechanism of CFS was also analyzed, revealing abnormalities in NK cell function and immune factors in the immune system, dysfunction of the hypothalamic-pituitary-adrenal axis in the neuroendocrine system, and disorders of energy and lipid metabolism in the metabolic system.

This paper focuses on the study of acupuncture and moxibustion treatment of CFS, traces back to the historical application of acupuncture and moxibustion treatment of CFS, analyzes the relationship between the pathological mechanism of CFS and acupuncture and moxibustion intervention, expounds the theoretical basis of traditional Chinese medicine and modern mechanism of action of acupuncture and moxibustion treatment, and introduces the results of clinical trials, efficacy evaluation methods, and individualized treatment strategies for acupuncture and moxibustion treatment of CFS.

The innovative application of acupuncture techniques, such as electroacupuncture and acupoint catgut embedding, as well as the synergistic effect of acupuncture combined with traditional Chinese medicine and psychotherapy, are shown. At the same time, disputes and challenges in the efficacy, safety, and ethics of acupuncture treatment for CFS were pointed out, and future research directions, potential breakthroughs, and international cooperation opportunities of acupuncture treatment for CFS are discussed. This study provides a comprehensive reference for clinical treatment and research on CFS.

Source: Wang D, Yang T, Cui Y, Qu Y, Feng C, Sun Z, Zhang M. From tradition to healing: the promise of acupuncture in managing chronic fatigue syndrome. Front Med (Lausanne). 2026 Jan 20;12:1724290. doi: 10.3389/fmed.2025.1724290. PMID: 41641244; PMCID: PMC12865710. https://pmc.ncbi.nlm.nih.gov/articles/PMC12865710/ (Full text)

The Gut-Brain-Immune Axis in Environmental Sensitivity Illnesses: Microbiome-Centered Narrative Review of Fibromyalgia Syndrome, Myalgic Encephalomyelitis/Chronic Fatigue Syndrome, and Multiple Chemical Sensitivity

Abstract:

Environmental sensitivity illnesses-including fibromyalgia syndrome (FMS), myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), and multiple chemical sensitivity (MCS)-are chronic, disabling disorders characterized by hypersensitivity to environmental stimuli, persistent fatigue, widespread pain, and neurocognitive and autonomic dysfunction. Although their diagnostic criteria differ, increasing evidence suggests overlapping clinical features and shared biological mechanisms. A unifying hypothesis highlights the gut-brain-immune axis, where alterations in the intestinal microbiome, epithelial barrier dysfunction, and aberrant immune signaling interact with central sensitization and systemic metabolic dysregulation.

Recent studies demonstrate reduced microbial diversity, depletion of anti-inflammatory taxa (e.g., Faecalibacterium prausnitziiBifidobacterium), and enrichment of pro-inflammatory Clostridium species across these conditions. These shifts likely alter production of short-chain fatty acids, amino acid metabolites, and complex lipids, with downstream effects on mitochondrial function, neuroinflammation, and host energy metabolism. Moreover, emerging clinical interventions-including probiotics, prebiotics, synbiotics, and fecal microbiota transplantation-suggest a potential role for microbiome-targeted therapies, though controlled evidence remains limited.

This review synthesizes current knowledge on microbiome alterations in FMS, ME/CFS, and MCS, emphasizing their convergence on metabolic and immune pathways. By integrating microbial, immunological, and neurophysiological perspectives, we propose a microbiome-centered framework for understanding environmental sensitivity illnesses and highlight avenues for translational research and therapeutic innovation.

Source: Watai K, Taniguchi M, Azuma K. The Gut-Brain-Immune Axis in Environmental Sensitivity Illnesses: Microbiome-Centered Narrative Review of Fibromyalgia Syndrome, Myalgic Encephalomyelitis/Chronic Fatigue Syndrome, and Multiple Chemical Sensitivity. Int J Mol Sci. 2025 Oct 14;26(20):9997. doi: 10.3390/ijms26209997. PMID: 41155291. https://www.mdpi.com/1422-0067/26/20/9997 (Full text)

Relationships between fatigue, cognitive function, and upright activity in a randomized trial of oxaloacetate for myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

Background: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a debilitating condition characterized by fatigue, cognitive impairment, and reduced physical function. Oxaloacetate (OAA), a metabolic compound with potential mitochondrial and neuroprotective effects, has shown promise in reducing fatigue symptoms in ME/CFS. However, the interrelationships between fatigue, cognitive performance, and physical activity and their responsiveness to treatment remain poorly understood in ME/CFS.

Methods: This 90-day randomized, double-blind, controlled trial evaluated the effects of 2,000 mg/day OAA or a control of 2,000 mg rice flour in 82 adults with ME/CFS. Self-reported fatigue (Chalder Fatigue Questionnaire), cognitive function (DANA Brain Vital), and upright activity time (UP Time) were assessed at baseline and three follow-up visits. Linear mixed-effects models examined associations between fatigue severity and cognitive/physical function, with treatment group interactions. Responder status at the last visit (Visit 4) was classified based on ≥15% fatigue reduction and/or ≥10% cognitive improvement.

Results: The OAA group showed greater cognitive improvement over time, with a significant between-group difference at Visit 3, 60 days into the trial, (p = 0.034) and trends at other visits. Higher fatigue was significantly associated with reduced cognitive gains in the OAA group (β = −0.34, p < 0.0001), but not in controls. UP Time increased modestly in the OAA group, reaching significance at Visit 2, day 30 (p = 0.044), though fatigue was not a strong predictor of UP Time in either group. At Visit 4, day 90, Global and Fatigue Only Responders were more frequent in the OAA group, while Cognitive Only Responders were more frequent in controls, though group differences did not reach statistical significance (p = 0.10).

Conclusion: OAA supplementation was associated with improved cognitive performance and small improvement in UP Time in ME/CFS participants receiving OAA. Fatigue–cognition coupling was particularly strong in OAA-treated participants, suggesting a potentially targetable phenotype. These findings underscore the importance of multidimensional outcome measures in ME/CFS clinical trials and support the need for more research and trials of metabolic interventions in ME/CFS.

Source: Vernon Suzanne D. , Rond Candace , Sun Yifei , Roundy Shad , Bell Jennifer , Rond Bella , Kaufman David L. , Cash Alan B. , Yellman Brayden , Bateman Lucinda. Relationships between fatigue, cognitive function, and upright activity in a randomized trial of oxaloacetate for myalgic encephalomyelitis/chronic fatigue syndrome. Frontiers in Neurology, Volume 16 – 2025. DOI=10.3389/fneur.2025.1691147 ISSN=1664-2295 https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2025.1691147/full (Full text)

The potential therapeutic approaches targeting gut health in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): a narrative review

Abstract:

Background: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a complex disorder characterized by persistent fatigue and cognitive impairments, with emerging evidence highlighting the role of gut health in its pathophysiology. The main objective of this review was to synthesize qualitative and quantitative data from research examining the gut microbiota composition, inflammatory markers, and therapeutic outcomes of interventions targeting the microbiome in the context of ME/CFS.

Methods: The data collection involved a detailed search of peer-reviewed English literature from January 1995 to January 2025, focusing on studies related to the microbiome and ME/CFS. This comprehensive search utilized databases such as PubMed, Scopus, and Web of Science, with keywords including “ME/CFS,” “Gut-Brain Axis,” “Gut Health,” “Intestinal Dysbiosis,” “Microbiome Dysbiosis,” “Pathophysiology,” and “Therapeutic Approaches.” Where possible, insights from clinical trials and observational studies were included to enrich the findings. A narrative synthesis method was also employed to effectively organize and present these findings.

Results: The study found notable changes in the gut microbiota diversity and composition in ME/CFS patients, contributing to systemic inflammation and worsening cognitive and physical impairments. As a result, various microbiome interventions like probiotics, prebiotics, specific diets, supplements, fecal microbiota transplantation, pharmacological interventions, improved sleep, and moderate exercise training are potential therapeutic strategies that merit further exploration.

Conclusions: Interventions focusing on the gut-brain axis may help reduce neuropsychiatric symptoms in ME/CFS by utilizing the benefits of the microbiome. Therefore, identifying beneficial microbiome elements and incorporating their assessments into clinical practice can enhance patient care through personalized treatments. Due to the complexity of ME/CFS, which involves genetic, environmental, and microbial factors, a multidisciplinary approach is also necessary. Since current research lacks comprehensive insights into how gut health might aid ME/CFS treatment, standardized diagnostics and longitudinal studies could foster innovative therapies, potentially improving quality of life and symptom management for those affected.

Source: Hsu CY, Ahmad I, Maya RW, Abass MA, Gupta J, Singh A, Joshi KK, Premkumar J, Sahoo S, Khosravi M. The potential therapeutic approaches targeting gut health in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): a narrative review. J Transl Med. 2025 May 11;23(1):530. doi: 10.1186/s12967-025-06527-x. PMID: 40350437. https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-025-06527-x (Full text)

Research Supports the Integration of Acupuncture in Mainstream Health Care for the Management of Chronic Diseases

Abstract:

Purpose: To address the role of acupuncture in mainstream health care for symptom relief, condition outcome, pain management, and shared therapy in resolving chronic diseases. This article explores how acupuncture education can adapt to meet the standards required for inclusion in conventional health care.

Objectives: To discuss the future of acupuncture education and its part in training providers for inclusion in a comprehensive health care system that involves physician acupuncturists and licensed acupuncturists for treating and managing specific chronic diseases. To strategize the future of acupuncture education at an advanced clinical level that fosters incorporating acupuncture therapy into selected allopathic settings. To encourage the recognition of translational research for promoting the acceptance of acupuncture by providers and insurers.

Conclusion: Translational research employs clinical evidence to support acupuncture therapy when incorporated into selected areas of allopathic practices, including pain management, palliative care for patients with end-stage cancer, sleep disorders, anxiety disorders, post-traumatic stress, female hormonal conditions such as premenstrual syndrome and menopausal syndrome, as well as chronic fatigue syndromes including Myalgic encephalomyeltitis/chronic fatigue syndrome (ME/CFS) and Long COVID. Advanced clinical training in acupuncture schools and postgraduate certification courses are required to prepare acupuncturists to safely and effectively provide the specialized integrative acupuncture services needed in these clinical areas.

Source: Williams JE, Kim Y, Moramarco J. Research Supports the Integration of Acupuncture in Mainstream Health Care for the Management of Chronic Diseases. Med Acupunct. 2025 Apr 17;37(2):106-111. doi: 10.1089/acu.2024.0108. PMID: 40308724; PMCID: PMC12038303. https://pubmed.ncbi.nlm.nih.gov/40308724/

Recovery from Myalgic Encephalomyelitis/Chronic Fatigue syndrome developed after severe acute respiratory syndrome coronavirus 2 vaccination: A case report

Abstract:

Background: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a neurological adverse effect after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccinations. However, clinicians do not recognize the condition well, and no case report has shown a full recovery.

Case presentation: We present a 65-year-old Japanese female who experienced severe fatigue, postexertional malaise, orthostatic intolerance, and various symptoms after her third SARS-CoV-2 vaccination. Following thorough examinations and excluding other potential diagnoses, she met the diagnostic criteria for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). The symptoms persisted for 30 months and improved ultimately with comprehensive treatment and a self-management strategy, including pacing management, pharmacological treatments, and psychiatric interventions to support those struggling with the despair over the devastating symptoms.

Conclusion: This case report describes ME/CFS following the SARS-CoV-2 vaccination and its full recovery. It illustrates the importance of considering the differential diagnosis of psychiatric disorders and addressing the condition through psychiatric interventions. Our findings provide new insights into treating ME/CFS and the vaccination-related adverse effects.

Source: Kurotori I, Sasao W, Abe M. Recovery from Myalgic Encephalomyelitis/Chronic Fatigue syndrome developed after severe acute respiratory syndrome coronavirus 2 vaccination: A case report. PCN Rep. 2025 Apr 27;4(2):e70111. doi: 10.1002/pcn5.70111. PMID: 40291166; PMCID: PMC12034265. https://pmc.ncbi.nlm.nih.gov/articles/PMC12034265/ (Full text)

Assessing fatigue in myalgic encephalomyelitis/chronic fatigue syndrome patients before and after treatment with bright light therapy: A prospective randomized controlled crossover study

Abstract:

Objective: The aim of the current study was to test the effectiveness of treatment with bright light therapy (BLT) on fatigue and cognitive function in patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). A randomized-controlled cross-over study design was chosen in order to provide all patients access to BLT treatment and account for placebo effects.

Methods: In this study, a total of 36 outpatients with a diagnosis of ME/CFS according to the criteria of the Institute of Medicine (2015) were randomly assigned to a cross-over design starting out either with BLT or waitlist for the course of 2 weeks with a washout phase in between. Portable light boxes emitting full-spectrum visible light with a luminance intensity of 10,000 lux were used by the participants at home. Primary outcome of the study was fatigue as assessed by Chalder Fatigue Score (CFQ) and the secondary outcome variable was cognitive function assessed per standardized test battery (Test of Attentional Performance – TAP).

Results: The primary outcome variable fatigue was not significantly improved after treatment with BLT compared to wait list in the full crossover design, although fatigue scores improved immediately after two weeks of BLT. Additionally, patients showed decreased reaction time after treatment with BLT in a subtest of TAP compared to wait list. Over 45 % of patients were diagnosed with postural tachycardia syndrome.

Conclusion: BLT for two weeks is not effective for the treatment of fatigue in ME/CFS, but it might have beneficial effects on attention in patients with ME/CFS. The clinical trial is registered with www.

Clinicaltrials: gov (NCT06635928).

Source: Ludwig B, Hauer L, Böck M, Schillerwein-Kral C, Weyer L, Moser D, Zehetmayer S, Trimmel K, Seidel S. Assessing fatigue in myalgic encephalomyelitis/chronic fatigue syndrome patients before and after treatment with bright light therapy: A prospective randomized controlled crossover study. Sleep Med. 2025 Mar 14;129:369-374. doi: 10.1016/j.sleep.2025.03.003. Epub ahead of print. PMID: 40120538. https://www.sciencedirect.com/science/article/pii/S1389945725001200 (Full text)