Vitamin C is LIKELY SAFE for most people when taken by mouth in recommended doses. In some people, vitamin C might cause nausea, vomiting, heartburn, stomach cramps, headache, and other side effects.

Daily Intake Of Vitamin C 1000mg

The chance of getting these side effects increases the more vitamin C you take. Amounts higher than 2000 mg daily are POSSIBLY UNSAFE and may cause a lot of side effects. These may include kidney stones and severe diarrhea. In people who have had a kidney stone, amounts greater than 1000 mg daily greatly increase the risk of kidney stone recurrence.