B vitamins should be taken after meals, because B vitamins are usually water-soluble vitamins, also belong to the acidic vitamins, the commonality of acidic vitamins is that they will stimulate the mucous membrane of the gastrointestinal tract, with acid reflux, heartburn, nausea, vomiting and other adverse reactions, acidic vitamins have a certain corrosive and irritating effect on the mucous membrane of the gastrointestinal tract, so it is recommended to take them after meals, the best absorption time of vitamins is 30 minutes after meals. At this time, the gastrointestinal tract has already eaten food, will not cause a certain irritating effect and effect on the gastrointestinal tract mucosa. In addition, acid reflux is significantly reduced after eating, especially for patients with a previous history of gastric disease, such as chronic gastric ulcer, duodenal bulb ulcer, erosive gastritis, and reflux gastritis must take vitamin B 30 minutes after meals to avoid adverse reactions in the digestive tract.