Birth control pills with vitamin C can promote the metabolism of birth control pills and reduce the side effects of birth control pills. 1. After taking birth control pills, especially emergency contraceptives, side effects such as nausea, vomiting and other gastrointestinal discomfort often occur. Taking birth control pills and supplementing with vitamin C can effectively reduce or even alleviate these gastrointestinal side effects, and can accelerate the metabolism of birth control pills in the body. 2. Women who have been taking birth control pills for a long time are prone to skin pigmentation, and taking vitamin C can effectively prevent pigmentation through its antioxidant and anti-free radical effects. If there is no vitamin C around, you can consume some foods rich in vitamin C instead, such as orange juice, etc., can play a similar effect.