Does not function as sodium/D-glucose symporter (PubMed:13130073, PubMed:20421923, PubMed:22766068). However, may function as a D-glucose sensor by generating a D-glucose-induced depolarization which is pH-independent, Na(+)-dependent at neutral pH and probably H(+)-dependent at acidic pH (PubMed:13130073, PubMed:17110502, PubMed:20421923, PubMed:22766068). {ECO:0000269|PubMed:13130073, ECO:0000269|PubMed:17110502, ECO:0000269|PubMed:20421923, ECO:0000269|PubMed:22766068}. This is the function of Ensembl gene identifier ENSG00000100191 (SLC5A4, solute carrier family 5 member 4).