What is the recommended daily calcium supplementation for reducing oxalate absorption in SBS?

• A. 800-1200 mg/day in divided doses not exceeding 500 mg per dose
• B. 200-400 mg/day
• C. 1500-2000 mg/day
• D. 100-300 mg/day

Answer: (A)

Calcium in the gut binds oxalate to form insoluble calcium oxalate, which is then excreted in the stool, reducing how much oxalate is absorbed. In short bowel syndrome with fat malabsorption, oxalate absorption can increase, so providing calcium helps ensure there’s enough calcium present in the intestine to bind oxalate during digestion, lowering urinary oxalate excretion. The recommended approach is about 800–1200 mg of calcium per day, taken in divided doses with meals and not exceeding 500 mg per dose. Dividing the doses maximizes calcium availability for binding throughout the meal and improves absorption, whereas a single large dose is less efficiently absorbed and provides less ongoing binding.