Vitamin D3 is a fat-soluble vitamin, and the best time period is to take it orally 30 minutes after meals, because fat-soluble vitamins are taken before eating certain compounds containing lipids, or eating food, so that the metabolism and decomposition of vitamin D3 is accelerated through lipolysis. So in time after a dish rich in fats and oils, or after eating relatively more meat for lunch and dinner, taking vitamin D3 at 30-minute intervals can achieve maximum bioavailability. In addition, after taking vitamin D3, it is recommended to go outdoors for some photosynthesis, that is, sunlight and sun exposure, so that vitamin D3 can be fully metabolized and bone calcium can be deposited on the bones, so that vitamin D3 can achieve the best bioavailability.