Many people like to sit on the balcony and bask in the sun through the glass, which is useless and ineffective. Laminated glass will absorb some ultraviolet rays, endangering the production of vitamin D. It is best to bask in the sun outdoors. The main function of people in the sun is that the skin helps the body to produce vitamin D according to direct ultraviolet rays. Except for a few vitamins, vitamin D is considered to be both a vitamin and a hormone.

Most vitamins can't be produced by the body itself, but must be ingested by food or drugs, while vitamin D can be produced by skin irradiated by ultraviolet rays. Vitamin D is mainly used to form and keep bones strong, especially to improve the body's absorption of sodium ions. Can be used for preventing rickets in children, rickets in adults and joint pain. Lack of vitamin D can also lead to rickets in children and adults. Other typical symptoms include muscular atrophy, acute enteritis, diarrhea, insomnia and anxiety. Reducing the harm of some calcium can save more important calcium in the body. Finally, vitamin D can help improve the absorption and metabolism of hyperosteogeny and increase the calcium content in blood.

Food intake is formed by sunlight. Foods containing vitamin D actually include fish, eggs and high-protein foods. However, even if there are not many ingredients containing vitamin D, it is unrealistic to get enough vitamin D from food. Sunbathing needs scientific norms. It is suggested that everyone should be exposed to natural light for 20-30 minutes from 10 to 3 pm every day. At this time, the vitamin D produced by human body can meet the requirements of obviously recommended daily intake. Through the glass, most of the ultraviolet rays in the sun can't pass through the laminated glass, so it can't help the human body to form vitamin D and can't help the absorption of calcium.