Which statement about chronic kidney disease (CKD) and osteoporosis is true?

• A. CKD cannot contribute to osteoporosis
• B. CKD only affects bone density in children
• C. CKD does not alter calcium/phosphate balance
• D. CKD can contribute to osteoporosis

Answer: (D)

Chronic kidney disease disrupts mineral metabolism and bone remodeling, so it can contribute to osteoporosis. The kidneys help regulate calcium and phosphate levels and activate vitamin D. When kidney function declines, phosphate accumulates and activation of vitamin D decreases, leading to lower calcium absorption from the gut. The resulting drop in serum calcium stimulates parathyroid hormone release (secondary hyperparathyroidism), which increases bone breakdown to raise calcium levels. Over time, this abnormal bone turnover weakens bone structure, raising the risk of osteoporosis and fractures. This relationship isn’t limited to children—it affects adults with CKD as well.