The reason is as follows: 1. Soybean milk is rich in calcium, and vitamin D is needed to increase the absorption rate of calcium, if you drink soybean milk in the morning after the morning and afternoon outdoor activities, sunlight exposure of the skin to produce rich vitamin D, can make the morning eat in the calcium in soybean milk to get good absorption and metabolism. 2. The actual food therapy point of view is that soy milk is cold, and the morning is the most vigorous Yang Qi time, so in the morning drink soy milk can make the body’s Yin and Yang balance is well maintained, and is conducive to physical health.