Absorption of nutrients

Vivian Imbriotis | Jan. 21, 2026

CHOs: Salivary and pancreatic amylase lyse polysaccharides into disaccarides \(\to\) brush border lyses to monosacchardies \(\to\) glucose absorbed by SGLT1

Lipids: Bile acids emulsify triglyceride into micelles \(\to\) Pancreatic lipase lyses triglyceride into glycerol + 3 FFAs \(\to\) diffuse into enterocytes \(\to\) lymph as chylomicrons.

Proteins: Acid denatures protein \(\to\) endopeptidases (pepsin and trypsin) lyse internal bonds \(\to\) exopeptidases lyse external bonds \(\to\) oligopeptides absorbed by faciliated diffusion by PEPT1 and others.

Sodium is actively absorbed (mostly by symport with nutrients), and water with it by osmosis.

Potassium is absorbed by passive, unregulated paracellular diffusion.

Fat-soluable vitamins (ADEK) absorbed by passive diffusion

Water-soluable vitamins (BC) are absorbed by active transport (either with Na+ or H+)