SLC5A6 encodes a sodium-dependent multivitamin transporter (SMVT) that mediates electrogenic transport of pantothenate, biotin, lipoate, and iodide across cell membranes 1. The transporter functions as a Na+-coupled symporter with 2:1 Na+:substrate stoichiometry, utilizing the electrochemical sodium gradient to drive substrate uptake 2. SLC5A6 is essential for intestinal absorption of biotin and pantothenic acid across the brush border membrane and critically supplies these vitamins to the brain across the blood-brain barrier, accounting for 88.7% of biotin and 98.6% of pantothenic acid uptake in cerebral microvascular endothelial cells 2. These vitamins serve as cofactors for coenzyme A (CoA) biosynthesis, which is required for cellular metabolism including the tricarboxylic acid cycle, lipid synthesis, and histone acetylation 1. Mutations in SLC5A6 cause severe multivitamin deficiency disorders presenting with neurological symptoms, developmental delay, sensory polyneuropathy, and immunodeficiency 34. Early supplementation with biotin and pantothenic acid can stabilize or reverse these manifestations 43. Additionally, SLC5A6 upregulation by the MYC oncogene promotes tumor metabolic reprogramming toward anabolic pathways, making it a potential therapeutic target in cancer 5.