As the COVID-19 pandemic continues to impact millions worldwide, a recent study has shown that intravenous vitamin C may not be an effective treatment for hospitalized patients. The study, which combined data from two harmonized randomized clinical trials, aimed to determine whether vitamin C could improve the outcomes of COVID-19 patients. Here are the key findings:
- Study Details: The two clinical trials took place on four continents, enrolling critically ill patients in intensive care units and patients who were not critically ill between July 23, 2020, and July 15, 2022. Patients were randomly assigned to receive intravenous vitamin C or a control (placebo or no vitamin C).
- Primary Outcome: The primary outcome measured was a composite of organ support–free days, which is a combination of days alive and free from respiratory and cardiovascular organ support in the intensive care unit up to day 21, along with survival to hospital discharge.
- Results: The findings showed that vitamin C had low efficacy and high probabilities of harm and futility. Specifically, among critically ill patients, there was only an 8.6% probability of efficacy in improving organ support–free days, with a 91.4% probability of harm and 99.9% probability of futility. Among non-critically ill patients, the probability of efficacy was 2.9%, with probabilities of harm and futility exceeding 97.1% and 99.9%, respectively.
- Secondary Outcomes: The study also examined secondary outcomes, including 90-day survival and 28-day death or persistent organ dysfunction. These outcomes consistently showed low probabilities of vitamin C efficacy and higher probabilities of harm and futility.
- Adverse Events: Serious adverse events related to vitamin C, such as methemoglobinemia, hypoglycemia, and hemolytic anemia, were reported in a small number of patients.
- Study Limitations: The study combined data from two trials with different designs, and the results were underpowered to detect differences between the trials. It also noted the potential impact of response-adaptive randomization and possible differences in post-randomization care.
In conclusion, the study suggests that intravenous vitamin C is unlikely to improve outcomes for hospitalized COVID-19 patients. Further research may be needed to explore potential treatments for this viral infection as the pandemic continues to evolve.