Rickets is primarily caused by a deficiency in vitamin D and mainly affects normal growth and development, with very little to no impact on intelligence. In the early stages of rickets, symptoms mainly include irritability, restlessness, and excessive sweating at night. The body primarily exhibits symptoms such as sweating, night terrors, and irritability, with symptoms becoming significantly more pronounced. During this period, the main manifestations are skeletal deformities, which vary in different age groups. For example, there can be softening of the skull, as well as pectus excavatum, pectus carinatum, and X-shaped or O-shaped legs. In severe cases, spinal deformities may also occur.