25 hydroxyvitamin D is an indicator of the vitamin D content in the body, which can affect the absorption and metabolism of calcium and phosphorus in pregnant women, which may lead to fetal growth and developmental delay, and even osteoporosis in pregnant women. The vitamin D supplement is usually caused by insufficient dietary content or less sunlight, and can be improved through dietary supplementation and daily care. 1.Dietary supplementation: you can eat foods rich in vitamin D in appropriate amounts, such as cod liver oil, animal liver, lean meat, egg yolk, dairy products, mushrooms, etc. You can also take vitamin D drops in appropriate amounts, but you need to control the intake, too much intake may lead to vitamin D toxicity, and can be guided by a physician. The specific amount of supplementation, can also be moderate supplementation after dynamic testing; 2, daily care: usually in the morning and afternoon sunshine, participate in outdoor activities, the ultraviolet light in the sun can promote the synthesis of vitamin D, absorption, while paying attention to rest, avoid strain, relax, and maintain a positive and optimistic attitude.