Sunscreen prevents vitamin D synthesis should be guaranteed 3 times a week 15 minutes sun

3 times per week for unprotected sun (data map) Beijing time June 1 according to the Daily Mail of the UK, the advent of summer, adequate sun exposure to vitamin D is very beneficial. According to medical experts, more and more people in today's society lack vitamin D, which has adverse health effects.　　How much do you know about vitamin D?　　Q: What are the main physiological functions of vitamin D?　　A: vitamin D mainly has the following physiological functions: 1, improve the body of calcium, phosphorus absorption, so that plasma calcium and plasma levels of phosphorus to reach saturation level.　　2, promote growth and bone calcification, promote the sound of teeth, 3, through the intestinal wall to increase the absorption of phosphorus, and through the renal tubules to increase the absorption of phosphorus; 4, maintain the normal level of citric acid salt in the blood, 5, prevent the amino acid through the kidney loss.　　Therefore, vitamin D is important to form bones and maintain bone health, especially for pregnant women and children with special attention to vitamin D supplementation. Q: The source of vitamin D: people mainly through the sun to supplement vitamin D, because people's natural food in addition to marine fish, vitamin D is very small. The average person gets very little more than 100IU of vitamin D from food daily, including babies. Mainly by sunlight in the skin generated. Windows or outdoor sunshine is required to receive reflected sunlight in the shade in summer. After exposure to ultraviolet light, the body's cholesterol can be converted into vitamin D.　　More than 80% of the vitamin D in the body comes from ultraviolet light in the sun. Q: Can I get a response from food: animal livers, fish oil and egg yolks are natural sources of vitamin D.　　The best known source of vitamin D is the dried mushroom, because the dried mushroom contains ergosterol is vitamin D2, after ultraviolet irradiation can be converted to vitamin D2, can greatly supplement the human body needs vitamin D.　　Q: How long does it take to get the sun to produce the required vitamin D per day? A: Between April and September, people with normal skin tone were basking three times a week, 15 minutes each time, and were not able to cover both hands, arms and face. To bask in the sun outdoors, you cannot bask in the sun through the window.　　Darker-skinned people have a slightly longer exposure to the sun.　　Q: Is it preventing vitamin D uptake by using shading screens or applying sunscreen?　　A: Yes, because most shades or sunscreen can stop ultraviolet rays, and UV rays can turn cholesterol into vitamin D. Q: Those people are less likely to have vitamin D? A: People who live in sunshine and less climate are prone to lack of vitamin D.　　Older people, especially those who have darker skin or stay indoors for a long time, are more likely to lack vitamin D.　　Q: What symptoms indicate a lack of vitamin D? A: Some people who lack vitamin D do not show symptoms, or just faint symptoms such as fatigue or pain.　　Muscle pain or weakness is also a symptom, either back pain or leg pain.　　Q: How to diagnose and treat vitamin D deficiency? A: The blood examination can investigate the vitamin D level, thus learnedWhether a person lacks vitamin D.　　If necessary, the doctor will prescribe vitamin D pills to supplement vitamin D.　　Q: What is the long-term effect of vitamin D deficiency? A: A slight lack of vitamin D usually has no serious consequences. Chronic vitamin D deficiency increases the risk of osteoporosis. Severe vitamin D deficiency in children can cause rickets. In short, if vitamin D is absent, it will increase the risk of rickets, severe cavities, rickets, and senile osteoporosis. (Lin Yu) Sina Health Exclusive manuscript, reprint please specify the source!