I am 33 years old female, how many gram of vitamin c should i take in a day?

None: Eat an orange or two every day. It's also a good source of fiber. Don't drink oj as it's not a good source of fiber and certainly not as filling. Check this out for other dietary sources of vitamin c: http://www.Nlm.Nih.Gov/medlineplus/ency/article/002404.Htm. If you decide to eat a grapefruit daily, check w/your pharmacist to make sure you're not taking some medication that may be affected.