Enables the transfer of a solute or solutes from one side of a membrane to the other according to the reaction: folic acid(out) + H+(out) = folic acid(in) + H+(in). The main folic acid symporter is the Proton-Coupled Folate Transporter (PCFT/SLC46A1), which has similar affinity for transport of reduced folates (5-methyl THF, 5-formyl THF) and folic acid.
folic acid:proton symporter activity