Improvement in Long COVID Brain Fog After Benfotiamine and Methylcobalamin Supplementation: Case Report Series and Review of the Literature

Abstract

Long COVID, or post-acute sequelae of SARS-CoV-2 infection (PASC), is a complex and debilitating condition characterized by persistent symptoms affecting multiple organ systems, including neurological and musculoskeletal domains. With limited definitive treatments currently available, exploration of adjunctive therapies is critically needed. Emerging evidence suggests that deficiencies in thiamine (vitamin B1) or vitamin B12, or impaired metabolism of these vitamins, may be a contributing factor in symptomatology associated with COVID-19 disease. Here we present a case series in which three people suffering from Long COVID reported improvement in neurocognitive symptoms (brain fog) within one month following supplementation with a proprietary formulation of oral benfotiamine, a lipid-soluble thiamine derivative, and methylcobalamin (vitamin B12). No baseline thiamine or vitamin B12 biomarkers were obtained prior to initiation of vitamin supplementation, and no cognitive assessments were performed prior to supplementation, limiting the causal inference that can be derived from these cases. While these observations do not establish efficacy, they are consistent with the findings of other researchers in which the use of vitamin B1 and vitamin B12 was found to improve COVID symptomatology. These results support the need for controlled studies incorporating neurocognitive outcomes and biomarker characterization to further evaluate the usefulness of these vitamins in the treatment of Long Covid.