The most common causes of chronic pain are osteoporosis and arthritis. In the United States, 50 million people suffer from joint pain every year. Taiwan Province Province is also very common. Dr. Hong, director of rheumatology department of Guotai Hospital, said that about 20% of China people suffer from arthritis. Whenever the seasons change or the weather is cold, the joints will be stiff and painful, which will affect the quality of life. Many people have to use painkillers to relieve pain, but if they use too much, they may have side effects, such as decreased physical activity, and patients will feel their overall health worse. Low vitamin d? Obesity is one factor. There are many reasons for vitamin D deficiency, including food imbalance, insufficient sunlight and genetic inheritance. According to research, obesity is also one of the reasons. Scientists found that the higher the body mass index, the lower the concentration of vitamin D in blood vessels (note 1). Every time the body mass index increases 10%, vitamin D will decrease by 4.2% (note 2). Vitamin D is an important nutrient for human body. If vitamin D in blood vessels is maintained at an appropriate level, it can stabilize mood, prolong life and relieve chronic pain. How to get enough vitamin D? Vitamin D, also known as "sunshine vitamin", can be synthesized in the sun for 15-30 minutes every day, while it takes longer for people with darker skin. Food is also a good source. According to the Cancer Clinical Research and Development Foundation, shark liver oil, sardines, herring and milk can be ingested as much as possible. Vegetarians can choose sweet potatoes, alfalfa, mushrooms and oats. According to the recommendation of the Department of Health of the Food and Drug Administration in 2009, the recommended daily intake of vitamin D for children under/kloc-0 and China people over 50 years old is 1 0 mg (400 international units IU). 1-China people aged 50 suggested that the daily intake of vitamin d should be 5 mg (200 IU). But the more vitamin D, the better. If you want to take vitamin D as medicine, you must do it under the guidance of a doctor, because excessive vitamin D can cause poisoning.