Which of the following is a factor associated with metabolic bone disease in inflammatory bowel disease?

• A. Malnutrition
• B. Vitamin D deficiency
• C. Corticosteroid therapy
• D. All of the above

Answer: (D)

Metabolic bone disease in inflammatory bowel disease arises from several related mechanisms that impact how well bone is formed and mineralized. Malnutrition common in IBD reduces the nutrients needed for bone synthesis, including calcium and protein, weakening bone structure. Vitamin D deficiency further lowers calcium absorption from the gut and can trigger secondary hyperparathyroidism, which drives bone loss. Corticosteroid therapy, frequently used to control inflammatory flares, directly suppresses osteoblast activity, increases osteoclast-mediated bone resorption, and can impair calcium handling by the kidneys and gut. Inflammation itself also stimulates factors that promote bone breakdown. Because these factors often occur together in IBD, all of the above contribute to metabolic bone disease.