Risk Factors for Secondary Hyperparathyroidism After Bariatric Surgery

The frequency of bariatric operations is rising rapidly as is the number of patients on long term follow-up. Therefore, it is important to study the nutritional and metabolic complications and establish preventive measures. Secondary hyperparathyroidism and metabolic bone disease are frequent after bariatric surgery and are caused by the reduced intake and absorption of calcium and vitamin D. Unfortunately, obesity itself poses a risk of vitamin D deficiency and secondary hyperparathyroidism, other risk factors being darker skin colour, increasing age and living at high latitude. These risks are further increased by bariatric surgery the type of operation being the most important risk factor. Purely restrictive operations carry the lowest risk, reduced calcium intake being the main cause for secondary hyperparathyroidism. In malabsorptive operations calcium and vitamin D malabsorption further increase the risk of secondary hyperparathyroidism and osteoporosis. Prevention can be efficiently established by supplementation with calcium and vitamin D dosed according to the degree of malabsorption.