A small clarification - all 3 of these vitamins participate in GABA synthesis. They are not GABA "receptor" agonists, but increase its synthesis. If you Google each one of them followed by "GABA pubmed" you will find the studies you need. Some of the studies with pyridoxine and biotin are posted on the forum too so searching the forum for things like "biotin GABA" should give the relevant results.
Wicked, thanks sir!