In this article you will learn:
The different forms of B12 and which are the most effective for supplementation
How to assess B12 status in your body correctly
Lazy Reader's Section:
There are two forms you should always opt for in supplements, methylcobalamin and hydroxocobalamin. For straight up B-12, this sublingual is a great option as hydroxocobalmin. To assess your body's stores is complicated, but a good place to start is to compare a SpectraCell test result with your genetic reports and a current MMA (methylmalonic acid) blood test.
Lazy Author Alert:
Everything in this article is based on extensive research, but if you want the full, glorious nerdy version - grab yourself a copy of my book Dance Your Way Through Life: A No Bullshit Guide to Hacking Your Body, Mind & Soul for Success and dive into over 1,600 scientific references, tests and other useful info.
Vitamin B12 is one of the many vitamins part of what I consider my "Everyday Basics for Optimal Health" and important for a variety of things including metabolism, sleep, mood, energy and cellular health. Most people don't get sufficient amounts of B12 because it is poorly absorbed in general, and the amounts you'd need to take to make a therapeutic difference are just impossible to get from food - especially if you're vegetarian or (worse) vegan.
Unfortunately, on top of this natural difficulty of absorption and lack in the diet - there are many genetic factors that influence how we utilize B12 which can further complicate the problem. As a simple reference before we dive into any of this stuff, I have lots of these considerations and even with 40,000% or more of the RDI of B12 per day - my body still takes a while to saturate its levels. Yikes!
Genes & B12
There are many genes involved in every nutrient, but a few key ones for B12 are the following:
MTHFR has become super popular lately because of its role in a fundamental process in the body called "methylation." Other nutrients contribute to the "methyl cycle," like folate (B9), but if you have crappy genetics in this area you may be a "slow methylator" and have an underperforming energy level and life.
The other three, MTR, MTRR and FUT2, all have to deal with how your body absorbs, recycles and processes B12. Don't worry if you have no clue how to look any of these up or what they even mean right now - just realize that there are many possibilities for things to go wrong in this area and also cloud judgment of how to measure B12 levels or whether or not a supplement is working for you.
Testing & B12
There are many tests you can take to evaluate B12 status, but unfortunately the only useful ones are expensive and usually not covered by insurance. I break these, and the above genetics, down more in my big book, so check that out for a more detailed approach if this resonates with you:
1. A simple B12 blood test
You can test your blood for B12 levels, but the problem with this test is that it doesn't distinguish between active and inactive B12. If you have genetic issues with the MTR and MTRR genes (the ones that deal with recycling B12, hence poor recycling) then you will accumulate inactive B12 and, as a result, show a high B12 level even though you may be deficient.
2. An MMA (methylmalonic acid) blood test
This is a more expensive blood test but a lot more accurate. MMA is a byproduct that relates to B12. If it is elevated then that can corroborate a B12 deficiency.
3. Serum MCV (mean corpuscular volume)
This is a cheap test that comes packed into a CBC or complete blood count. This measures the size of your red blood cells. Generally, if your B12 is lacking then the size will be bigger or outside the normal range. I used to use this test along with a live blood microscopy test to evaluate subclinical B12 deficiency. It's not the most accurate, but it can give you an idea. Unfortunately, because red blood cells are not metabolically active (once they are created, that's it) - this is more like a "time stamp" kind of test. Most red blood cells live around 3 months, so whatever score you have shows what your body has approximately 3 months ago - meaning your current efforts of supplementation and lifestyle change won't necessarily be reflected in this measurement.
4. Red blood cell B12 status
As to the point above, red blood cells are not metabolically active. They do not have a nucleus, divide and do all the things that full-fledged cells do (like your immune cells). They are more like little containers, and while testing red blood cells for their nutrient amounts may be better than plain blood testing - it's still not an accurate measurement of how your tissues are responding to nutrition.
5. White blood cell (lymphocyte) B12 status
Lymphocytes are metabolically active, have a nucleus and grow and divide during their lifetime. An advanced test called a SpectraCell Micronutrient Test is the gold standard here. Among many things you get through this test is a B12 rating, which basically tells you how your cells respond to a deprivation challenge when B12 is taken away from their environment. If you have lots of B12, they will grow just fine. If you are deficient, their growth will be impaired. I go into much greater detail about this test with one of SpectraCell's head of research, Nichole, in this episode on The Dance of Life Podcast.
6. Hair testing
Used by many practitioners, hair testing can give you a rating for the mineral cobalt as an indirect measurement of B12 status. I used to use this, MCV and live blood testing many years ago before all the fancy genetic screenings and new supplement forms there are today to make this easier. Today I don't bother with hair testing as I believe SpectraCell is far superior, but B12 is a water soluble vitamin and most people can't go wrong with taking a high quality methylated form or hydroxocobalamin form regardless of their status.
So, now that you've got all this info - what do you do? My advice would be first to get a genetic report and see how you fair in the above mentioned genes. Next I'd get a baseline through a SpectraCell or at the very least an MMA test. If you can afford the $400 or so, the SpectraCell test is an amazing test to do at least twice per year to keep tabs on your body's nutrient levels. If you are supplementing regularly, this is a must so you understand what is in balance and what isn't.
Once you have a rough idea how your body is fairing, and how your genetics are by default, grab yourself a quality form of B12 and re-test in 3-5 months. A good sublingual B12 supplement is this one, and if you are getting pills then opt for methylcobalamin as it is the most absorbable and friendly to people's genes. B12 is water soluble, meaning any unused amount will just get peed out - so don't be afraid of huge RDI numbers on the back of your pills. I've taken up to 80,000% of the RDI of B12 per day for months without any problems (not that you should).
A note about what may seem like a B12 allergy. You are not allergic to nutrients, because your body needs those, but rather what's happening is a case of mistaken identity. Remember how hair testing looks at cobalt for B12 status? That's because cobalt is part of its chemical structure (hence "cobalamin" on the end of all the forms). Cobalt is close to Nickel on the Periodic Table, and if you've had Nickel poisoning or exposure and your immune system freaked out, this may cause it to freak out at a high dose of B12. Work with your naturopath or practitioner to re-sensitize your body, detox the heavy metals from your tissues and get back to balance.