A bstract Background Sepsis remains a leading cause of death worldwide despite advances in management strategies. Preclinical and observational studies have found mortality benefit with high-dose vitamin C in sepsis. Our study aims to prospectively evaluate the effect of intravenous hydrocortisone, vitamin C [ascorbic acid (AA)], and thiamine (HAT) administration in reducing inpatient all-cause mortality among patients with septic shock. Materials and methods Our single-center, prospective, open-label, randomized controlled trial recruited patients with admitting diagnosis of septic shock and assigned eligible patients (1:1) into either intervention (HAT) or control group (routine). The HAT group received intravenous combination of vitamin C (1.5 g every 6 hours), thiamine (200 mg every 12 hours), and hydrocortisone (50 mg every 6 hours) within 6 hours of onset of septic shock admission. The treatment was continued for at least 4 days, in addition to the routine standard of care provided to the control group. Thiamine and hydrocortisone use in control arm was not restricted. Vitamin C levels were estimated at baseline and at the end of the 4 days of treatment for both groups. The primary outcome evaluated was mortality during inpatient stay. Results Among 90 patients enrolled, 88 patients completed the study protocol. The baseline characteristics between the HAT ( n = 45) and the routine ( n = 43) groups were comparable. The all-cause mortality in the HAT cohort was 57% (26/45) compared to 53% (23/43) in the routine care group ( p = 0.4, OR 1.19, 95% CI 0.51–2.76). The time to reversal of septic shock was significantly lower in the HAT (34.58 ± 22.63 hours) in comparison to the routine care (45.42 ± 24.4 hours) ( p = 0.03, mean difference −10.84, 95% CI −20.8 to −0.87). No significant difference was observed between the HAT and the routine care with respect to changes in sequential organ failure assessment (SOFA) scores at 72 hours (2.23 ± 2.4 vs 1.38 ± 3.1), the use of mechanical ventilation (48% vs 46%), and mean Vasoactive Inotropic Score (7.77 ± 12.12 vs 8.86 ± 12.5). Conclusion Intravenous administration of vitamin C, thiamine, and hydrocortisone did not significantly improve the inpatient all-cause mortality among patients with septic shock. Clinical significance HAT protocol does not reduce hospital mortality but decreases time to shock reversal in septic shock. How to cite this article Mohamed ZU, Prasannan P, Moni M, Edathadathil F, Prasanna P, Menon A, et al. Vitamin C Therapy for Routine Care in Septic Shock (ViCTOR) Trial: Effect of Intravenous Vitamin C, Thiamine, and Hydrocortisone Administration on Inpatient Mortality among Patients with Septic Shock. Indian J Crit Care Med 2020;24(8...