Vitamin C alone is not an effective method of birth control, as it doesn't prevent ovulation or fertilization in any way. Choose an alternate method of birth control, and don't forget to choose a second method to stay safer.
Birth control is by either taking birth control pills, using protection like condoms, or having surgery. Vitamin C will not prevent you from having a baby.
Ai yi yi, no! I'm not sure where you are getting your information, but you need to talk with someone qualified like a sex education teacher or a doctor.
Vitamin c is not an effective birth control method. That is silly - you find vitamin c in orange juice. It is not a spermicide at all. This is ridiculous.