Doctor's Best - Best Fully Active B-12 (contains cellulose and modified cellulose from soft woods) (Amazon Link)
As of yet, these have not been human tested to see how corny they may be. If you do use these successfully, let us know.
Update:
Doctor's Best - Best Fully Active Folate (on 9/10/13 the product did contain just MTHF with rice flour as a filler and the capsule, and just a few days later, now contains ascorbic acid, likely from corn - AVOID.) (Amazon Link)