Hi there, I'm a 26 year old, sexually active female. I'm currently on the birth control pill Alesse 28, which I've been taking for more than a year. I've never missed a pill and am very diligent about taking my pill at roughly the same time every day. I've recently started to be concerned about everyday vitamin supplements that may interfere with the efficacy of my pills. The internet contains vague information, but can anyone let me know if Vitamin C, Vitamin B12 or Vitamin E can decrease the efficacy of pills? I do take a lot of Vitamin C, but have recently stopped due to a concern with efficacy.