When is the best time to take vitamin D drops depends on the individual’s health condition, and it is generally recommended to take it between meals. The main function of vitamin D drops is to promote the absorption of calcium in the gastrointestinal tract, the reabsorption of calcium by the kidneys, and the deposition of calcium into the bone. It is recommended that vitamin D drops be taken between meals, such as after breakfast to before lunch and after lunch to before dinner, to achieve maximum bioabsorption utilization and less likely to damage the gastric mucosa. However, if the patient has gastrointestinal disorders, such as a previous history of chronic gastritis, duodenal ulcer, or gastric ulcer, it is recommended that it be taken preferably about 15-30 minutes after a meal. If vitamin D drops are used to treat vitamin D deficiency rickets, in order to avoid long-term overdose that may cause poisoning and other conditions, it is recommended to visit the internal medicine department or nutrition department of a hospital before taking it for trace elements and other related examinations, and then follow the doctor’s instructions for medication.