Vitamin D deficiency is very common, how common is it? Our recent article published in clinical nutrition (impact factor 4.476), the official journal of the European Society of Nutrition, has the highest impact factor published to date in China in the field of vitamin D deficiency epidemiology. We measured serum 25hydroxyvitamin D3 in 5531 Beijing residents from December 2011 to December 2013 and found that up to 97.1% of Beijingers did not reach the ideal level (>30ng/ml) and 87.1% were vitamin D deficient (<20ng/ml), which was more common in women than in men (89%), more severe in adolescents, more pronounced in the elderly It is more obvious in winter and spring. This number is alarming, but unfortunately, vitamin D deficiency is not generally taken seriously by clinicians and the public. Vitamin D is a very important nutrient and hormone to maintain human health, and its main function is to regulate calcium and phosphorus metabolism, but recently there is increasing evidence that vitamin D deficiency is associated with numerous diseases, including cardiovascular diseases, diabetes, hypertension, autoimmune diseases, the occurrence and prognosis of many malignant tumors such as breast cancer, colon cancer, prostate cancer, and certain infectious diseases such as tuberculosis, colds, etc. muscle weakness, back pain, anxiety and depression, and skin diseases. Serum 25OHD level reflects the overall level of vitamin D in the human body, and the American College of Endocrinology proposed in 2011 that for bone health, the ideal serum 25OHD level is above 30 ng/ml; between 21C29 ng/ml for vitamin D deficiency; <20 ng/ml for vitamin D deficiency, which can cause rickets in infants and children, and bone softening in adults, manifesting as low back pain, calf twitching, and muscle weakness. , calf twitching, and muscle weakness. However, numerous evidences show that higher levels of serum 25(OH)D would be more beneficial for health beyond bones and prevention of chronic diseases. Holick, a leading scholar in the field of vitamin D, believes that if the 25(OH)D level in the population reaches 50 ng/ml, it can lead to 100% reduction in rickets and bone tenderness, 75% reduction in various cancers, 80% reduction in type 1 diabetes, 50% reduction in type 2 diabetes, and 50% reduction in various fractures. type 2 diabetes by 50%, all kinds of fractures by 50%, falls in women by 72%, myocardial infarction by 50%, pre-eclampsia by 50%, and cesarean section by 75%. I have called attention to vitamin D deficiency at many academic conferences, and I have given many lectures in my hospital, but it is not enough. Let's take a few examples: 67-year-old male, diabetic from Manchuria. He came to Beijing to see his daughter and registered for a special needs number last September because of diabetes. His usual blood sugar control was fine, but he complained of significant weakness and poor stamina and was worried about whether it might be a complication of diabetes. I gave him a routine check of diabetes-related biochemistry and glycosylated hemoglobin in addition to vitamin D and PTH, and the result was that his vitamin D level was very low. Six months later, he came to my daughter's house for Chinese New Year during the Spring Festival, and came to me again during the period, complaining that he had been well for a while after the fight, but recently he was not well again, I checked his 25 hydroxyvitamin D again and found that it was still very low, even lower than six months ago. I told him that sunlight is very important to the human body, and that people in Europe and the United States like to go outdoors in the sun, which is very beneficial to human health. 30-year-old female, two years history of hyperthyroidism, first treated in Hong Kong, came to Beijing six months ago, now methimazole treatment for 2 years, now 10mg/d treatment for 3 months, nail function FT3 and FT4 are in the normal range, TSH 0.031, April 2015 by the patient's classmates working in our hospital referred to the clinic. She usually works under stress, is easily fatigued, often feels palpitations, sleeps poorly, wakes up early, and takes Valium and Synthroid for treatment. She has regular menstrual periods, but has significant dysmenorrhea and abdominal pain during each menstrual period, and is usually allergic and prone to allergies. On examination, her thyroid gland was 3 degrees enlarged, soft in texture, heart rate was 88 beats per minute, and her hands did not shake. I told her that these symptoms were not related to hyperthyroidism, and theoretically, since T3 and T4 were in the normal range, she would not have any hyperthyroid symptoms. She seemed to disagree with this statement, and I suggested that she have her vitamin D level checked, which she reluctantly accepted. She was diagnosed with vitamin D deficiency and given calcium preparations and a high dose of vitamin D3 orally, and was seen again a month later with a 25OHD level of 53.95ng/ml, complaining of markedly improved sleep, reduced palpitations, and a "particularly marked" improvement in strength. After 3 months, she told me that her dysmenorrhea, which had been bothering her for many years, had cleared up. A 40-year-old woman with diabetes mellitus for many years, usually with good blood sugar control, but often felt fatigue and weakness, often back pain, usually like to lie down after work, especially in winter every year, after sitting for a long time, the back pain is obvious. He was diagnosed with severe vitamin D deficiency and was given calcium preparations and high doses of vitamin D3 orally, and after one month, his 25OHD level was 40 ng/ml. To me, this is not surprising, in my clinic, with patience and a few more questions, I encounter several such patients every day, and through further examination of these people, it was found that almost all of them had vitamin D deficiency, and all of these people showed different degrees of improvement after my treatment, and after the treatment, the feedback often received was, "stamina is much better than before ", "legs are stronger than before", "back pain is better", "no more cramps, which were frequent " " Less sweating" "Sleep better" Remind parents to pay attention to their children's vitamin D levels, in my opinion, the health of primary and secondary school students in general is very poor, especially female students; pregnant women pay attention to vitamin D levels, vitamin D deficiency will affect the child's bone health and immune function, and give birth to a child prone to colds; pay attention to vitamin D levels, vitamin D deficiency will affect the child's bone health and immune function. Pay attention to the vitamin D level of the elderly, because many diseases are related to this, love your parents, then help them to check the 25 hydroxy vitamin D. Pay attention to your own vitamin D level, it will be your physical strength to improve a lot. My own 25 hydroxy vitamin D level is 55.4 ng/ml, I am taking vitamin D supplements for myself, and also for my family, how about you?