Rickets and osteoporosis are both caused by a lack of vitamin D and calcium. Rickets is commonly seen in infants and can present with abnormalities in skeletal development such as "ping-pong ball head", signs of wrist and ankle bracelets, square skull, funnel chest, pigeon chest, X-shaped legs, and O-shaped legs. Osteoporosis is a metabolic bone disease caused by reduced bone formation and increased bone resorption. It can be categorized according to its etiology into senile osteoporosis, postmenopausal osteoporosis, idiopathic osteoporosis, and secondary osteoporosis. Clinically, it can manifest as fatigue, bone pain, and fractures.