If you want to maintain normal immunity, you must ensure the supply of vitamin D. if you have the following symptoms and exclude the causes of other related diseases, your body may lack vitamin D. When the body lacks vitamin D What are the symptoms? 1. Often depressed. Vitamin D can maintain the normal level of serotonin in the brain. Serotonin is considered to be one of the participating elements of happiness and well-being. When it is lacking, it can lead to depression, listlessness, irritability, inability to lift spirit, and even weariness. 2. Weakness of limbs. There are vitamin D receptors in muscles. When lacking, the body is more prone to fatigue, muscle pain and limb weakness. 3. Sweating and cramping. Vitamin D can regulate calcium absorption, and deficiency will lead to osteoporosis, hyperhidrosis, cramps and other phenomena. 4. Often catch a cold. Vitamin D helps maintain normal immunity. Lack of vitamin D can lead to repeated infection or inflammation. 5. Increased hair loss. Vitamin D can maintain the normal growth of hair follicles. Lack of vitamin D can aggravate hair loss. The latest study found that taking vitamin D Reduce the risk of immune diseases by 22% Vitamin D is a very important and powerful vitamin, which can regulate calcium and phosphorus metabolism and promote bone growth. In addition, vitamin D has the function of immune regulation. A total of 25871 participants were recruited in one trial, with an average age of 67.1 years and an average follow-up time of 5.3 years. The trial was divided into two groups and four groups. The two groups were vitamin D group and placebo group. Vitamin D group: divided into "vitamin D3 + fish oil" and "vitamin D3 + placebo of simulated fish oil"; Placebo group: divided into "placebo simulating vitamin D + fish oil" and "placebo simulating vitamin D + placebo simulating fish oil". The results showed that the risk of disease in the vitamin D group was 22% lower than that in the placebo group. Compared with the placebo group, the risk of autoimmune diseases decreased by 31% in the "vitamin D3 + fish oil" group and 32% in the "vitamin D3 + simulated fish oil placebo" group. Researchers believe that one of the mechanisms of vitamin D regulating immunity is that its metabolite 1,25-hydroxyvitamin D3 can bind to vitamin D receptor and enhance immune function by regulating gene expression. In addition, 1,25-hydroxyvitamin D3 can regulate the proliferation of B cells, thus playing the role of anti-inflammatory and maintaining immunity. How should vitamin d be supplemented daily? You can eat and bask in the sun In all populations, people who are overweight or obese, people who are less exposed to the sun, breastfed infants and adolescents are very prone to vitamin D deficiency. If the above discomfort occurs, consult a doctor. Under the condition of sufficient calcium and phosphorus supply, the appropriate intake of vitamin D for adults is 10 μ g / day; 15 μ g / day for adults over 65 years old. There are two main methods of supplement: One is to directly eat foods containing vitamin D. For example, high-fat fish and eggs, animal liver, egg yolk, cheese and some mushrooms, but food sources alone can not meet daily needs. Second, bask in the sun. Regular exposure to the sun is the best source for the human body to obtain sufficient and effective vitamin D cheaply. As long as adults are often exposed to the sun, vitamin D deficiency generally does not occur. It is recommended that in non cold seasons, when the sun is mild, expose 30 cm of hands and feet every day and dry in the sun for 10-30 minutes. Don't wear sunscreen or glass, otherwise it's not conducive to the synthesis of vitamin D. For people prone to deficiency, vitamin D preparations can be supplemented under the guidance of doctors after excluding relevant contraindications in combination with the test results. At present, it is considered that the maximum tolerable intake of people over 11 years old is 50 μ g / day, and the intake of vitamin D should not exceed this amount, otherwise excessive accumulation of vitamin D in the body will cause poisoning. (outlook new era)