Zinc vs. Vitamin C: Which Is Better for Immune System Support

Vitamin C can help prevent colds in specific populations, including smokers, athletes, and people living in cold climates.
Taking zinc on the first day symptoms appear shortens the duration of respiratory viruses, such as the common cold and COVID-19.
While both vitamin C and zinc can cause gastrointestinal side effects, long-term use of zinc can also lead to more serious side effects, including a low blood cell count and a weakened immune system.

Vitamin C and zinc are nutrients that your immune system needs to help your body fight respiratory infections.

Zinc and Vitamin C Are Both Crucial For Immune System Function

Both zinc and vitamin C help the cells in your immune system work well and improve your body’s ability to combat viruses and swelling (inflammation).

Low levels of either zinc or vitamin C reduce your immune system’s ability to fight disease, making it more likely you will get sick.
Guidelines recommend that adults aim for 75 to 120 milligrams (mg) of vitamin C and 8 to 12 milligrams (mg) of zinc daily, depending on different factors.

These nutrients can be obtained through the diet or consumed as dietary supplements.
Boost your vitamin C intake with citrus fruits and vegetables, and your zinc levels by eating red meat and seafood.

Vitamin C May Work Better Than Zinc for Preventing Respiratory Viruses

Vitamin C may lower your risk of catching a cold, particularly if you are an older adult, live in an extremely cold climate, exercise strenuously, or smoke cigarettes.

Zinc is unlikely to prevent the common cold or COVID-19.45

Zinc lowers the risk of lung infection (pneumonia) in children who don’t consume enough zinc in their diet.

Zinc Is Better For Shortening How Long Colds Last

Zinc shortens the duration of a cold by approximately two days if taken at the first sign of symptoms. Keep in mind, though, that zinc supplements do not make symptoms of the common cold (such as runny nose, sneezing, cough, and fatigue) any less severe.

There’s some evidence that zinc can also shorten the length of COVID-19 and make the disease milder. People with COVID-19 who take zinc are less likely to be admitted to the intensive care unit (ICU) or to die from the disease.
Taking vitamin C regularly may make your colds a little shorter (usually less than a day) and your symptoms less severe.