Nutrients such as folic acid and fish oil can help determine the amount, character, and functioning of brain-altering neurotransmitters. If brain cells don’t get enough of the right nutrients, neutotranmitter systems can go awry with disastrous consequences. Your brain cannot function at peak form if you are low in the B vitamin folic acid. (Carper, Jean. Your Miracle Brain. pp 9-11, 206-207, 208, 221. NY: HarperCollins Publishers, Inc., 2000.)