Sunbathing should not be "long". Sunbathing usually lasts 10-20 minutes each time, ranging from 3 to 5 times a week. In the sun, you should "avoid sunburn, pay attention to applying sunscreen and cover your face and eyes." Besides, hiding behind the glass in the sun is no good. Therefore, it is generally said that simply supplementing calcium will be useless, and vitamin D must be supplemented to be effective. In particular, some friends who live in the North and South poles and work indoors all the year round can't guarantee to synthesize enough vitamin D, which is easy to cause diseases of teeth, bones and muscles.
We get 20 international units of vitamin D from sunlight for every square centimeter of skin, and a baby only needs 400 international units of vitamin D every day to meet the body's demand for calcium. Therefore, it is really possible to get more calcium in the sun and grow taller! Yang stands for strength, enthusiasm and positivity. Men's physical fitness is stronger when they work outside the home, while women's long-term responsibility for housework is relatively weak. Therefore, the most direct benefit of sunbathing to human body is that it can supplement the yang and make them healthier.
In winter, the direct sunlight gradually moves to the southern hemisphere, and the ultraviolet intensity on the earth in the northern hemisphere weakens, which does little harm to human body. Moreover, when the weather is cold, people have less outdoor activities and receive insufficient ultraviolet rays. At this time, people need more sunshine. My cousin Luo Shirong got hepatitis at the age of 30, so he can't go to work in winter. He is very weak. He has been sunbathing for four hours every day since he went to Wudalianchi for recuperation in the 1970s. When he came back from recuperation for the first time, he felt that he was full of inexhaustible energy and continued to work without rest in winter.