Sodium/ascorbate cotransporter. Mediates electrogenic uptake of vitamin C, with a stoichiometry of 2 Na(+) for each ascorbate. L-ascorbate(out) + 2 Na(+)(out) = L-ascorbate(in) + 2 Na(+)(in) Belongs to the nucleobase:cation symporter-2 (NCS2) (TC 2.A.40) family.