Why can you grow up healthily by sticking to the sun? What are the benefits to the human body?

Sunshine, air and water are the three treasures that nature gives to human health. The sun can grow healthily. The main benefit to human body is that it can make 7- dehydrocholesterol in human skin form vitamin D, which can promote the absorption of calcium. Ultraviolet rays in the sun can also kill bacteria and prevent diseases. Infrared rays can also increase the skin temperature and reduce the secretion of melatonin by the pineal gland. Melatonin can increase the depth of sleep, making it difficult for people to doze off during the day, but it can secrete more melatonin at night, increasing the depth and time of insomnia.