Vitamin B-9 (also known as folacin, folate or folic acid) is a vitamin found in small amounts in many foods including broccoli, Brussels sprouts and peas. It can also be taken as a nutritional supplement, either on its own or as part of a multivitamin preparation.
Vitamin B-9 helps produce and maintain new cells, helps maintain normal levels of some amino acids such as homocysteine and glutathione, and helps maintain normal levels of some neurotransmitters such as dopamine.
Some people think that individuals on the autism spectrum have significant metabolic abnormalities.
They also think that some of those metabolic abnormalities can be addressed by consuming more foodstuffs containing vitamin B-9 or by taking supplements of vitamin B-9, sometimes alongside supplements of other vitamins and minerals.