The reason I chose to focus on folate is that folic acid, the commonly used one in cheaper brands, clogs up your receptors while it's being converted to a bioactive form. The clearance rate changes substantially person to person, so you might be taking your multivitamin, thinking it's all good, but instead, you are chronically clogging up your folate receptors with the inert variety. Any natural folate you have through diet might even be blocked from use due to the overwhelming amount of inert folic acid you've consumed. MTHF, on the other hand, is immediately bioactive. It hits the receptors and triggers a response similar to natural folate's response.

Here's a little more information about why I chose folate to focus on. It's really a surprisingly sinister form to use. It can take some people hours before the folic acid converts fully.