Zinc is needed for normal immune function. Correcting an inadequate intake is important; taking too much for a long time can cause copper deficiency.
Vitamin C does not prevent colds in most people. Regular use may slightly shorten their duration; starting after symptoms appear has not shown consistent benefit.
Nutrition, sleep and recommended vaccinations remain foundations of good health. Supplements do not replace treatment for an infection. Compare ingredients and total doses across all the supplements you take.
Before use
The 1,000 mg vitamin C listing is an example of a product, not a daily dose recommended for everyone. Discuss high doses with a health professional if you are prone to kidney stones or have iron overload.
Educational information. Supplements do not replace a balanced diet or medical care.