The majority of dietary folate is reabsorbed via which mechanism?

• A. Oncotic pressure
• B. Enterohepatic circulation
• C. Plasma hydrostatic pressure
• D. Passive diffusion

Answer: (B)

Enterohepatic circulation recycles folate: the liver secretes folate into bile, which carries it into the small intestine where much of it is reabsorbed, especially in the ileum, returning folate to the bloodstream. This recycling preserves folate status and explains why most dietary folate is reabsorbed rather than lost. The other options aren’t mechanisms for folate reabsorption—the forces described by oncotic and hydrostatic pressures govern fluid movement, not nutrient reabsorption, and folate absorption relies on carrier-mediated transport rather than simple passive diffusion.