Popular belief is that vitamin C can cure the common cold. However, research about this claim is conflicting.
Although not fully proven, large doses of vitamin C may help reduce how long a cold lasts, by 8% in adults and 14% in children. Large doses of vitamin C do not protect against getting a cold.
The likelihood of success may vary from person to person. Some people improve, while others do not. Taking 1000 to 2000 mg per day can be safely tried by most people. Taking too much can cause stomach upset or lead to kidney stones.
People with kidney disease should NOT take vitamin C supplements.
Large doses of vitamin C supplementation are not recommended during pregnancy.
A balanced diet almost always provides the required vitamins and minerals for the day.
Alternative Names
Colds and vitamin C
Images
References
Barrett B. The common cold. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 329.
National Institutes of Health, Office of Dietary Supplements website. Vitamin C: fact sheet for consumers. ods.od.nih.gov/factsheets/VitaminC-Consumer/. Updated March 22, 2021. Accessed February 10, 2026.
Redel H, Polsky B. Nutrition, immunity, and infection. In: Blaser MJ, Cohen JI, Holland SM, et al, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 10th ed. Philadelphia, PA: Elsevier; 2026:chap 11.
Shah D, Sachdev HPS. Vitamin C (ascorbic acid) deficiency and excess. In: Kliegman RM, St. Geme JW, Blum NJ, et al, eds. Nelson Textbook of Pediatrics. 22nd ed. Philadelphia, PA: Elsevier;2025:chap 68.
Review Date 1/14/2026
Updated by: Linda J. Vorvick, MD, Clinical Professor Emeritus, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.