According to research, every square centimeter of skin exposed to the sun for 3 hours can produce about 20 international units of vitamin D. Even if the baby is wrapped tightly, as long as the face is exposed to the sun every day 1 hour, it can produce 400 international units of vitamin D. Close to the baby's daily vitamin D requirements.

Sunbathing can help people get vitamin D, which is also the main source of vitamin D, also known as "sunshine vitamin". The source of vitamin D3 contained in human skin is made by obtaining ultraviolet rays from sunlight and converted into vitamin D, which can help the human body absorb calcium and phosphorus and make children's bones grow strong and strong. Can be used for preventing rickets and rickets in children. For adults, it can prevent osteoporosis and rheumatoid arthritis.

1. Sunbathing can prevent skin diseases. Proper exposure of the skin to ultraviolet rays can effectively kill bacteria on the skin and increase the skin's resistance.

2. Sunbathing can also enhance the immune function of human body and increase the vitality of phagocytes. Ultraviolet rays in the sun have a strong bactericidal ability. Generally, bacteria and some viruses will be killed if they are exposed to the sun for half an hour or several hours.

3. Sunlight can also mediate people's life rhythm and psychology. Sunbathing can promote blood circulation, enhance metabolism and regulate the central nervous system, thus making people feel relaxed and comfortable.

4. Sunbathing can improve male androgen level, enhance sexual desire and improve sperm quality. Because the testosterone level in human blood will increase with the increase of vitamin D content in the body. The study also confirmed once again that the daily sunshine of 1 hour can increase testosterone in human body by 69%.

5. Ultraviolet rays in sunlight can also stimulate bone marrow to make red blood cells and improve hematopoietic function, thus preventing anemia.

First, the best time to bask in the sun:

The best time for sunbathing is from 6 am to 10. At this time, the infrared rays in the sun are strong and the ultraviolet rays are weak, which can play the role of promoting blood circulation and removing blood stasis; 4 pm to 5 pm is also the best time to bask in the sun, which can promote the absorption of calcium and phosphorus in the intestine, enhance physical fitness and promote normal calcification of bones. However, the sunshine time is longer in summer, and the heat wave is rolling at 4-5 pm, so the sunshine time can be slightly delayed.

These are only for ordinary people, not including pregnant women, children and the elderly. These special people need more calcium and pay more attention to sunbathing.

1, pregnant women:

Need to bear the calcium needs of two people. It is enough to bask in the sun for half an hour every day in summer, and not less than 1 hour every day in winter. You can't stay indoors all day, because your body is inconvenient.

2. Children:

The need of development makes them need a lot of calcium, and they are most prone to calcium deficiency. So starting from two months, you should go outdoors to bask in the sun every day. 9~ 10 in the morning and 4~5 in the afternoon are suitable time to go out. The time to receive sunlight can be gradually extended from the first ten minutes to one hour. When the weather is not too hot, you can bask in the sun and stay in the shade for a while.

Don't be in the sun directly in summer, because scattered ultraviolet rays can also be received in the shade. Old people: it is also the key group of calcium supplementation. You can sunbathe before 9 am and after 4 pm, but you'd better not go out alone to sunbathe. If you fall asleep in the pleasant sunshine, you may catch a cold. Find a few companions and talk while walking. They are easily exposed to ultraviolet radiation.

Second, matters needing attention:

1, sunbathing has so many benefits, but it is not advisable to overdo it. Generally speaking, people with fair skin can meet the needs of vitamin D production by sunbathing 10~20 minutes three to four times a week. If you want to synthesize vitamin D artificially, you'd better choose to bask in the sun from 10 to 2 pm. When the weather is very hot, sunbathing for 5~ 10 minutes at a time is enough. Friendly reminder: if you sit in the sun in hot season, you must wear a sun hat. )

It should be reminded that although sunbathing is beneficial to physical and mental health, you should not choose to sunbathe for nearly three or two hours at noon. Absorbing a small amount of sunlight can "nourish the body" and make people healthy and energetic, but consuming too much energy may lead to skin cancer. We should change with the seasons and decide how long it will take to get good results according to our own experience. And to synthesize vitamin D, you don't need to sunbathe naked, just wear short-sleeved shirts and shorts.

3. In addition, it needs special attention that excessive exposure can easily turn human moles into melanoma or skin cancer. When you are in the sun, you must wear a sunscreen to cover the mole.

1) It is best to wear red clothes in the sun, because the long-wave radiation of red clothes can quickly "eat" the short-wave ultraviolet rays with strong lethality, and it is best not to wear black clothes.

2) Take off your hat and gloves when you are in the sun, expose your skin as much as possible, and let the sun get in close contact with your skin.

3) Sunbathing through the glass window is not effective. It is best to be outdoors or on a spacious balcony.