They are "soft bones"; cannot mineralize organic bone once made. Produces pain when weight is put on the bones and causes bending (bow legs). Rickets are a bigger problem in kids because they are still growing. At epiphyseal plate, the cartilage can't be mineralized on the bottom, which is a point of weakness on the bone. It is caused by malnutrition, insufficient calcium, phosphorus, and vitamin D, improper absorption, or inadequate sunlight in the diet.