Involved in the sodium-dependent cotransport of myo-inositol (MI) with a Na(+):MI stoichiometry of 2:1. Exclusively responsible for apical MI transport and absorption in intestine. Can also transport D-chiro-inositol (DCI) but not L-fructose. Exhibits stereospecific cotransport of both D-glucose and D-xylose. May induce apoptosis through the TNF-alpha, PDCD1 pathway. May play a role in the regulation of MI concentration in serum, involving reabsorption in at least the proximal tubule of the kidney. MI transport activity inhibited by D-chiro-inositol (DCI), phlorizin (Pz) and sodium (Na(+)). Located on apical membrane of enterocytes. Expressed in kidney and small intestine. Belongs to the sodium:solute symporter (SSF) (TC 2.A.21) family.