While vitamin C (ascorbic acid) is an essential nutrient, it's possible to have too much of it.
Vitamin C is a water-soluble vitamin that supports normal growth and development and helps your body absorb iron. Because your body doesn't produce or store vitamin C, it's important to include vitamin C in your diet. For most people, an orange or a cup of strawberries, chopped red pepper, or broccoli provides enough vitamin C for the day.
For adults, the recommended daily amount for vitamin C is 65 to 90 milligrams (mg) a day, and the upper limit is 2,000 mg a day. Although too much dietary vitamin C is unlikely to be harmful, megadoses of vitamin C supplements might cause:
Diarrhea
Nausea
Vomiting
Heartburn
Abdominal cramps
Headache
Insomnia
Remember, for most people, a healthy diet provides an adequate amount of vitamin C.
https://www.mayoclinic.org/healthy-l...c/faq-20058030