What is the recommended dose of vitamin c for a cold?

How much vitamin C should you take for a cold?

Most adults take 500 to 1000 mg daily once symptoms appear. Research shows doses above 200 mg per day offer little extra benefit once a cold starts.

What happens if you take too much vitamin C?

Doses over 2000 mg can cause diarrhea, nausea, and stomach cramps. People with kidney stones or hemochromatosis should avoid high doses entirely.

How does vitamin C compare with other cold remedies?

Zinc lozenges started within 24 hours of symptoms may shorten colds by a day. Over-the-counter pain relievers ease aches and fever. Vitamin C shows only modest shortening of cold duration, usually less than a day.

Can vitamin C prevent colds in the first place?

Regular daily intake of 200 mg or more modestly reduces cold risk in people under heavy physical stress. Average adults see almost no preventive benefit from routine supplementation.

When does vitamin C start working against a cold?

It shows effect only if taken at the first sign of illness. Starting after symptoms are fully developed adds almost no measurable improvement.

Why are people still taking high-dose vitamin C for colds?

Some older studies suggested larger doses could cut duration by 8 percent, but later reviews found the effect small and inconsistent.