Bariatric surgery is a type of weight loss surgery that is commonly used to treat obesity. However, this surgery can also affect the body’s calcium and PTH metabolism, leading to the development of secondary hyperparathyroidism (SHPT). Several factors contribute to the development of SHPT after bariatric surgery. Malabsorption of calcium due to reduced intestinal surface area, decreased intake of calcium-rich foods, and altered vitamin D metabolism play a significant role. The loss of weight-bearing adipose tissue can also disrupt the balance between bone formation and resorption, leading to increased bone turnover and calcium release from the skeleton. The management of SHPT after bariatric surgery involves a multidisciplinary approach. Calcium and vitamin D supplementation is essential to correct deficiency and maintain bone health. However, achieving optimal calcium and vitamin D levels can be challenging due to malabsorption issues and the need for higher supplementation doses. In some cases, pharmacological interventions such as calcimimetics or PTH analogs may be required to control PTH levels. However, these medications should be used cautiously due to limited data on their safety and efficacy in the bariatric surgery population. Prevention of SHPT is an important aspect of managing patients undergoing bariatric surgery. Nutritional counseling and regular monitoring of calcium, vitamin D, and PTH levels can help identify and address deficiencies early on. Additionally, using procedures that preserve the duodenum and proximal jejunum, such as duodenal switch or biliopancreatic diversion with duodenal switch, may reduce the risk of developing SHPT.