Rickets, also known as vitamin D deficiency rickets, is primarily caused by insufficient vitamin D leading to abnormalities in calcium and phosphorus metabolism in the body. This results in the failure of calcium and phosphorus to deposit normally in the bone-forming areas, leading to incomplete mineralization of the bone tissues of the growth muscles, manifesting as a chronic nutritional disease characterized by skeletal abnormalities. The main causes are improper feeding methods, the addition of cod liver oil, residential environment, outdoor activity time, repeated respiratory infections, maternal calcium deficiency during pregnancy, and the season of birth. It is generally recommended for mothers to supplement appropriate amounts of vitamin D and calcium during pregnancy. After birth, babies should regularly supplement vitamin D and receive adequate sunlight, as insufficient ultraviolet light is one of the main causes of vitamin D deficiency. Lack of outdoor activities, primarily staying indoors, or having ultraviolet light blocked by dust, smoke, clothing, or ordinary glass can all lead to vitamin D absorption problems. Therefore, it is advised for children to have appropriate outdoor activities to prevent the onset of rickets.