The diagnosis of rickets in infants should rely on the level of 25-hydroxyvitamin D3 in the blood and the examination of the long bones through X-rays imaging, rather than early symptoms. However, due to the young age of infants, it is recommended to supplement vitamin D within two weeks after birth. If the supplementation is not timely, some early clinical manifestations may appear occasionally, such as brachycephaly, bowed legs, and pigeon chest in infants. Additionally, there may be abnormalities in the nervous system, such as unstable sleep, easily startled and crying, and increased excitability. Therefore, it is necessary to identify the condition through the aforementioned tests and then proceed with symptomatic treatment.