Decoding Vitamin B-12: From Digestion to Detection
I am sharing about vitamin B-12 because I have been seeing low B-12 levels in clients and friends lately. B-12 plays a larger role in our optimal health than most realize, and it has a rather complicated way it becomes available to the body. In this post, I’m hitting the highlights on B-12 sources, digestion, what impacts it’s absorption, and how to know if you are low in B-12.
What is B-12?
B-12 is a key vitamin humans get in our diet primarily through all animal-based food sources. Small amounts of B12 are in vegetarian sources like nutritional yeast, tempeh, and some mushrooms.
What does B12 do?
Red Blood Cell formation
DNA formation
Key player in the nervous system and brain cell functions,
and more.
How might you feel if don’t have enough B12?
Tired/fatigue, irritable, fuzzy thinking (can look like dementia if has gone on for a long time), headaches, depression, numbness/tingling in hands and feet, weakness in muscles, decreased appetite, nausea,
How we get B-12 from food into our bloodstream
B-12 requires stomach acid to get the pH of the stomach very low (we’re talking 1-2.0 pH) so that it can 1)break the protein apart that B12 is attached to and release it from the protein AND
2) let R-proteins and Intrinsic Factor (IF) know to come and get B-12. Intrinsic factor (IF)and RProtein are like Uber - it needs to know to come get the B12 and take it where it needs to go.
Your stomach acid release can be impacted by chronic stress, aging (over 60), long-term use proton pump inhibitors (aka - PPIs like Prilosec and Prevacid*), gastric bypass surgery or gastric sleeve, gut infections like H-pylori or candida, hiatal hernia, or auto-immunity of gut cells. If any of these are happening, you may not be able to have adequate digestion in your stomach and have a reduced ability to have R proteins intrinsic factor take up B-12.
Your pancreas also needs the signal of the low pH of the stomach to release its digestive enzymes in the duodenum to tell R protein your job here is done, it’s all up to IF now. Without proper pancreatic signal and function, B-12 may get bound up to R protein and not hand the job over to IF.
If the stomach is not the issue, there could be absorption issues in the small intestine. B-12 gets dropped off in the bottom part of the ileum*. The small intestine only recognizes B-12 with intrinsic factor (IF), it’s sorta like your iPhone face recognition when you wear sunglasses or your face is obscured it won’t unlock your phone and let you in.
If you have inflammation in your small intestines from food intolerances, celiac, bowel resection, small intestinal infections from bacteria or parasites then there may be problems at the absorption site to get all the B12 absorbed.
HOW TO TEST FOR B12:
B-12 is not commonly checked in standard blood tests, usually a you need to complain about a variety symptoms or specifically ask for B-12 to be checked. The reference range for B-12 in blood tests is quite large and typically will see 200- 1000 pg/mL on your lab report. Many people will have symptoms when lab test reads in the 300’s, some will report minor symptoms in the low 400s. Ideally we want B-12 lab test to be at least 500 or more.
If a doctor does not run a B-12 blood test, I will look to the CBC test (complete blood count) - sometimes the MCH and MCHC will be off and will give me clues that something is up and a follow-up B12 test is requested.
Sometimes serum B-12 may not catch deficiency, the serum B-12 test could be normal or even high when there is a B-12 deficiency!! Luckily the MMA (methyl-melanic acid) test is more accurate in testing a B12 deficiency. I find that many conventional doctors will not test for this because it’s more expensive and insurance has its rules on what they deem medically necessary testing for MMA that they have play by. There are always ways to get the tests you need to get all the information, they just may not be covered by insurance.
What to do if B12 is low?
Depending on how low — if it’s low-low I have the client find a safe resource to get a B12 injection so they can start to feel better almost immediately (within 1-5 days they can feel dramatically better). Then, I recommend people take sublingual B-12 supplements - it will get absorbed under the tongue, so we are bypassing any issues that may be going on in the digestive tract. Finally, I like to work with the client to see what is driving the low B12 — is it diet related, drug interactions, gut function issues, and so on.
If you are a vegan (and some vegetarians), you will need to take B-12 supplements to ensure you are getting adequate amounts.
If you are feeling tired, moody, fuzzy brained, or have some tingling in your hands or feet, please request to have your B-12 tested! Chronic deficiencies in B-12 can lead to non-reversible symptoms in nerve and brain tissue.
*the non-Brand names often prescribed are: pantoprazole and omeprazole
*the ileum is the upper part of the small intestine - the small intestine is made up of 3 parts - the duodenum, ileum, jejunum
