Sodium/glucose cotransporter 1 is a protein that in humans is encoded by the SLC5A1 gene. 
>Glucose transporters are integral membrane proteins that mediate the transport of glucose and structurally-related substances across cellular membranes. Two families of glucose transporter have been identified: the facilitated diffusion glucose transporter family (GLUT family), also known as 'uniporters,' and the sodium-dependent glucose transporter family (SGLT family), also known as 'cotransporters' or 'symporters' (Wright et al., 1994). The SLC5A1 gene encodes a protein that is involved in the active transport of glucose and galactose into eukaryotic and some prokaryotic cells. [supplied by OMIM]^.
This gene encodes a member of the sodium-dependent glucose transporter (SGLT) family. The encoded integral membrane protein is the primary mediator of dietary glucose and galactose uptake from the intestinal lumen. Mutations in this gene have been associated with glucose-galactose malabsorption.
Actively transports glucose into cells by Na(+) cotransport with a Na(+) to glucose coupling ratio of 2:1. Efficient substrate transport in mammalian kidney is provided by the concerted action of a low affinity high capacity and a high affinity low capacity Na(+)/glucose cotransporter arranged in series along kidney proximal tubules.