There's a lot of talk in the MTHFR community about the importance of avoiding folic acid, (the synthetic form of folate/vitamin B9), and sticking with natural sources of dietary folate and supplemental methylfolate. And that's great! It's one of the most important pieces of advice that a MTHFR can receive. However, what's discussed less often, but is also super important, is avoiding one of the most commonly used synthetic forms of vitamin B12, cyanocobalamin.
If you couldn't already guess, the form of vitamin B12 that MTHFRs should be taking is methylcobalamin. Both cyanocobalamin and methylcobalamin contain a cobalt ion. The main difference between these two forms of vitamin B12 lies in which type of molecule is attached to the cobalt ion. Methylcobalamin contains a methyl group and cyanocobalamin contains....get ready for it...cyanide. Eeek, right?! Why would anyone ever do such a thing?
Well, it's more cost-effective, stable, and most people are able to effectively detox that cyanide molecule without too much of a problem. However, those with the MTHFR mutation have an impaired ability to detox. You can probably see where this is going. One cyanide molecule wouldn't do too much harm, even for a MTHFR. If you supplement with cyanocobalamin over a span of time, however, you will deplete your glutathione stores (your body's master detox agent). If the cyanocobalamin supplementation continues, you could end up with a buildup on cyanide in your cells. Those with poor kidney function are especially vulnerable.
So the moral of the story? If you want to avoid taking a dash of cyanide in your daily vitamin, avoid cyanocobalamin, one of the synthetic forms of vitamin B12. Instead, opt for a vitamin that contains methylcobalamin, which is the ideal form for someone with the MTHFR mutation to take.
Did you know that this synthetic form of vitamin B12 contains cyanide? Which form do you take in your multivitamin or B complex supplement? Tell us about it!