What is absorbed in the intestine? Each department has its own autonomous processes of absorption👇🏻 The small intestine absorbs water and minerals: sodium, calcium, iron, magnesium, chlorine, and others. But in the large intestine, the final breakdown of proteins and the microbiological synthesis of vitamins (especially some B vitamins and vitamin K) take place. While in the stomach only ethyl alcohol and short-chain fatty acids are absorbed.