Abstract 15125: L-Arginine and Vitamin C Improve Symptoms of Long-COVID: Results of a Nationwide Multicenter Study

Introduction: Mounting evidence indicates that endothelial dysfunction and oxidative stress play crucial roles in the pathophysiology of COVID-19 and Long-COVID. Hypothesis: We hypothesized that a supplementation combining L-Arginine (to improve endothelial function) and Vitamin C (to reduce oxidation) could have beneficial effects on Long-COVID symptoms. Methods: We designed a nationwide multicenter clinical study, in which a survey assessing several symptoms that have been previously associated with Long-COVID was administered to COVID-19 survivors; the subjective perception of the tolerance to the effort was measured as well, trough the Borg scale. Patients were divided in two groups, with a 2:1 ratio: the first group included patients treated with L-Arginine + Vitamin C, whereas the second group was treated with multivitaminic combinations (alternative treatment). Before administering the survey, patients completed 30 days of treatment. Results: 1590 patients were initially enrolled, of which 1390 successfully completed the study. Following a 30-day treatment with L-Arginine + Vitamin C, the survey revealed that patients in this treatment group had significantly lower scores compared to the other group. There were no other significant differences between the two groups. Furthermore, when examining the subjective perception of the tolerance to the effort (modified Borg scale), we observed a significantly lower value (p<0.0001) in the L-Arginine + Vitamin C patients compared to the alternative-treatment arm. Conclusions: Our findings indicate for the first time that the supplementation with L-Arginine + Vitamin C has favorable effects in Long-COVID, in terms of reducing its typical symptoms and improving the perceived tolerance to effort.