In the setting of steatorrhea, which statement best describes oxalate absorption?

• A. Fatty acids bind calcium, increasing oxalate absorption
• B. Oxalate is excreted unchanged in stool
• C. Oxalate is degraded by pancreatic enzymes
• D. Calcium binds fatty acids, freeing oxalate to be absorbed

Answer: (D)

In steatorrhea, excess fatty acids in the gut bind calcium to form insoluble soaps, which reduces the calcium available to bind oxalate. Without calcium binding oxalate, more free oxalate remains soluble and is absorbed in the colon, increasing overall oxalate absorption. This is why the statement that calcium binds fatty acids, freeing oxalate to be absorbed, best describes the situation. Pancreatic enzymes don’t degrade oxalate, and oxalate is not simply excreted unchanged; its absorption increases due to the calcium sequestration by fatty acids, contributing to higher oxalate levels and a risk of kidney stones.