One of the most common other nutrients to consider when supplementing the methylation cycle is the proper form of B12. There are 3 different types of B12 that are considered very beneficial to the body (hydroxy B12, methylcobalamin or adenosylcobalamin). Many automatically think that if you have an MTHFR defect, then you need the form of B12 called methylcobalamin, but that is simply NOT true. 

It’s important to realize that the MTHFR status does not necessarily determine the type of B12 that’s best for you, instead it’s the status of genes like COMT, MTR, MTRR as well as VDR Taq. It is true that methylfolate and methylcobalamin work together synergistically along the methylation cycle pathway, but that doesn’t necessarily mean that if you tolerate methylfolate well you’ll also need, want or tolerate methylcobalamin well (even if that’s what most doctors, nutritionists, etc. are currently saying right now).

It seems there may be a general lack of education available to most doctors about the different forms of B12 and what those forms are as well as how they get converted within the body and what each is most beneficial for (not to mention which set of genes or genetic mutations could benefit most from which B12 type). So do your homework when it comes to B12 to see which you may tolerate best.

The most common form of B12 that you’ll find everywhere is cyanocobalamin and it is not very active or beneficial to the body because the absorption rate is fairly low, that’s because the body has to convert it first into hydroxy B12, and from there the hydroxy B12 has to be converted into both adenosylcobalamin and methylcobalamin. But if the body has genetic mutations then these conversions don’t happen well at all and the effect is the body does not get the absorption or use of the nutrient.

If you have your 23andme genetic test results, you can use those to help guide you as you try the specific B12 forms to see how they do for you. You’ll notice below that, according to Dr. Amy Yasko, the most well tolerated active form of B12 for folks seems to be hydroxy B12. Every single one of the genetic combinations she lists below should be able to tolerate B12 in the form of hydroxy B12 (and this is why our methylation protocol suggests hydroxy B12 as the B12 form to begin with):

• Folks with multiple COMT mutations tend to do very well with hydroxy B12 (it helps mop up excess peroxynitrites which can cause problems)
• Folks with MTR & MTRR mutations may do well with methylcobalamin & adenosylcobalamin supplementation
• And Dr. Amy Yasko (https://dramyyasko.com) talks about folks with a particular mutation status for COMT & VDR Taq as best needing the below forms of B12: