Vitamin D deficiency rickets is a systemic chronic nutritional disease characterized by skeletal lesions due to the disorder of calcium and phosphorus metabolism caused by the lack of vitamin D in the body, which is mainly divided into four stages: 1. It will lead to skeletal lesions, such as square cranium or beaded chest, chicken chest, and may also appear bone deformation due to soft bone, such as X-shaped leg, O-shaped leg, etc. In serious cases, it will lead to spinal deformation and scoliosis; 3, recovery period, after treatment or vitamin D supplementation, clinical symptoms and signs will disappear and be reduced, there is no obvious clinical manifestation at this time; 4, sequelae period, after treatment After the vitamin deficiency is improved, there is also no obvious clinical symptoms in this period, but you will see the bone deformity caused by the disease, such as O-leg, X-leg, chicken breast, etc. commonly.