GI Vitamin Absorption
- Beyond nutrients, water, and important electrolytes the alimentary tract must absorb a variety of critical small molecule vitamins. Hydrophobic fat soluble vitamins (Vitamins A, D, E, K) are absorbed together with other lipids using general mechanisms of GI Lipid Absorption. Most water-soluble vitamins are absorbed through secondary active transport via vitamin-specific Na-Vitamin symporters in the small intestine. However, Vitamin B12 has a unique mechanism for absorption which will be described in a Vitamin B12 page, once it is written.