Methylation so far just remember we do not know everything yet......

As you can see on the diagram the MTHFR enzyme determines how fast supplemental & dietary folate is turned into 5-MTHF.  This is  the only form of folate that reduces homocysteine & is necessary for the production of our #1 methyl donor, SAMe.

If you look at the junction with the second circle you can see that once MTHFR produces 5-MTHF, methyl-folate then donates or gives its methyl group (CH3) to cobalamin to make the active form of B12, methyl-cobalamin .  The MTR enzyme plays a critical role in transferring the methyl group from 5-MTHF to cobalamin.

In the second circle the methyl-cobalamin donates its methyl group to homocysteine to make methionine (this is important because we want to prevent the buildup of homocysteine).  The MTRR enzyme recycles B12 to make sure it stays active & viable, which means it is able to accept the methyl group from 5-MTHF .

Various mutations in the 3 above mentioned enzymes (MTHFR, MTR & MTRR) has been observed to reduce folate activity & thus increase homocysteine levels.
 
5-MTHF has important advantages over synthetic folic acid:

• it is well absorbed even when gastrointestinal pH is altered
• its bioavailability is not affected by metabolic defects.
• Using 5-MTHF instead of folic acid reduces the potential for masking haematological symptoms of vitamin B12 deficiency 

The 2 exciting things are;

1. We can test MTHFR in a blood test and this can indicate to some extent what form of folate is the best to start with.  If MTHFR works fine then folic acid is good for you.  If the enzyme is not functioning due to a genetic adnormality the whole cycle comes to a standstill right up at the beginning.  This will slow down cellular growth and repair in the body and effect some neurotransmitters.
2. 5-MTHF is now available as a supplement in Australia