Vitamin C is generally recommended to be taken after meals for good results. Vitamin C is one of the most common vitamins, which has strong antioxidant and reducing properties and is one of the essential vitamins for the normal functioning of the body. It is best to take vitamin C orally after a meal, but if it is taken before a meal, because vitamin C has an acidic composition, to a certain extent, the gastrointestinal tract has a certain degree of irritation, if the patient has gastritis or a fulminant ulcer may induce aggravation, or even cause perforation, and also reduce its absorption rate. Vitamin C is a water-soluble vitamin, taking it after meals can increase its absorption efficiency, the effect will be better. As long as the normal population ensures adequate intake of vegetables and fruits, vitamin C deficiency is generally not caused and no additional supplementation is necessary. If supplementation is needed, it must be done under the guidance of a doctor.