Case Report: Mitochondrial insufficiency underlies cholinergic failure in post-vaccination long COVID: a candidate treatment protocol.

An 80-year-old male with severe long COVID developed acute deterioration following COVID-19 vaccination despite ongoing cholinergic therapy (Mestinon 90 mg daily). A comprehensive mitochondrial support protocol targeting NAD+ repletion, electron transport chain function, and oxidative stress was initiated, with all components delivered in fresh-squeezed orange juice. Clinical response was dramatic within 48 h, with sustained functional recovery over 6 weeks. Challenge-rechallenge testing demonstrated rapid symptom recurrence and resolution with three key observations: missed doses, wrong component sequence, and substitution of water for orange juice. This final observation suggests citric acid may function as a rate-limiting Krebs cycle substrate, consistent with impaired endogenous citrate synthesis in severe long COVID. This case suggests that cholinergic support may require concurrent metabolic foundation including direct substrate supplementation, and some long COVID manifestations may be metabolically reversible with multi-pathway intervention. As a single self-case report, these findings generate hypotheses for systematic investigation rather than establishing treatment guidelines.