Mediates thiamine transport. Also mediates choline transport, although the underlying transport mechanism remains to be elucidated (PubMed:40972734). {ECO:0000269|PubMed:40972734, ECO:0000305|PubMed:24509276}. This is the function of ENSG00000183780 (SLC35F3, solute carrier family 35 member F3).