JMIR Publications

ABSTRACT

Background:

Community-acquired pneumonia (CAP) remains a leading cause of hospitalisation, morbidity, and mortality worldwide, particularly among older adults and those with multimorbidity and frailty. Despite advances in antimicrobial therapy, clinical outcomes have improved little over recent decades, highlighting the need for safe, inexpensive adjunctive treatments. Vitamin C plays a critical role in immune function, redox homeostasis, and endothelial integrity, all of which are disrupted during acute infection. Hypovitaminosis C is common in hospitalised CAP patients and has been associated with increased disease severity, longer length of stay, and worse outcomes. However, prior randomised trials of vitamin C have produced inconsistent results, largely focusing on critically ill septic patients, employing short treatment durations, and frequently discontinuing therapy abruptly.

Objective:

The VitCAP trial aims to evaluate whether high-dose oral vitamin C (sodium ascorbate), administered over an extended period, improves clinical recovery and patient-centred outcomes in adults hospitalised with community-acquired pneumonia.

Methods:

VitCAP is a single-centre, randomised, double-blind, placebo-controlled, parallel-group clinical trial conducted at a tertiary hospital in Australia. Adults aged ≥18 years hospitalised with CAP will be randomised within 48 hours of admission in a 1:1 ratio to receive either oral sodium ascorbate (1 g three times daily for 7 days, followed by 500 mg twice daily for 30 days) or a matching placebo, in addition to standard care. Randomisation will be computer-generated with allocation concealment via a centralised pharmacy service, and all participants, clinicians, investigators, and outcome assessors will remain blinded. The primary outcome is time to clinical stabilisation, defined by standard physiological criteria. Secondary outcomes include early clinical response, symptom burden at 30 days, ICU admission, need for ventilatory or vasopressor support, length of stay, all-cause mortality at 30 days and 6 months, hospital readmission, health-related quality of life, and changes in inflammatory biomarkers (C-reactive protein and procalcitonin). Analyses will follow the intention-to-treat principle. The primary outcome will be analysed using Cox proportional hazards regression adjusted for prespecified covariates, with sensitivity analyses including restricted mean survival time.

Results:

Recruitment is planned for 124 participants to provide 80% power to detect a clinically meaningful difference in time to clinical stabilisation, accounting for attrition. Results will be reported following CONSORT guidelines.

Conclusions:

The VitCAP trial is designed to address key evidence gaps by evaluating sustained oral vitamin C supplementation in hospitalised CAP patients using clinically meaningful and patient-centred outcomes. If effective, vitamin C could represent a low-cost, scalable adjunct to standard CAP management. Clinical Trial: ACTRN12625001361493