As vitamins go, vitamin B12 is a pretty important one.
It’s one of the “essential nutrients” that we humans can’t make on our own, so we must obtain it from our diets instead. Vitamin B12 has a broad range of roles in our body — from helping to make DNA and transport iron throughout our systems to protecting our nerves and manufacturing nerve-signaling compounds called neurotransmitters. If you don’t get enough of it, you can suffer from a specific type of severely energy-sapping anemia as cells throughout the body are deprived of oxygen. After a while without enough B12, you can have serious, irreversible nerve damage that results in numbness and tingling in the hands and feet, difficulty walking or all of the above.
Fortunately, though, vitamin B12 isn’t so hard to get enough of because it’s so widely dispersed in the food supply and daily needs are relatively low. It naturally exists in animal-derived foods like meat, poultry, fish, dairy and eggs, and is found in fortified foods including cereals, energy drinks, vitamin waters, bars and non-dairy “milks” that are fortified with the nutrient. Even most vegetarians are typically able to meet their requirements without too much trouble. And even if your diet falls short for a few days, your liver can store a multi-year supply of vitamin B12; this means that occasional overages — like from an energy drink or holiday party cheese plate binge — will be squirrelled away for future use.
[See: What All Plant-Based Eaters Need to Know About Vitamin B12.]
For all of these reasons, you would think that most Americans should be able to maintain vitamin B12 levels in a normal range from diet alone. (Those following a strict vegan diet, however, are an exception, and may need a supplement if they don’t consume significant amounts of vitamin B12-fortified foods.)
And yet, it’s not terribly uncommon for vitamin B12 levels to come up low in routine blood tests. This is particularly so among the 60-and-older crowd, as risk of vitamin B12 deficiency increases as we age due to a natural decline in stomach acid levels. (A highly acidic stomach is required to absorb the vitamin B12 from our diets.) Similarly, chronic use of perpetually popular acid-reducing medications for acid reflux disease increases risk for a B12 deficiency.
[See: How to Survive Acid Reflex — Without a Pill.]
But younger people who eat a varied diet and don’t use acid-reducing medications should not turn up with vitamin B12 deficiencies. Still, they do. And, when this happens, many doctors simply recommend taking daily high-dose, sublingual (under the tongue) vitamin B12 supplements or monthly injections to remedy the deficiency. Often, they forget to stop and ask, “Why does this young and seemingly healthy person have a vitamin B12 deficiency to begin with?”
This lack of curiosity may be problematic. Because vitamin B12 deficiency can often signal that something is amiss in your digestive tract, it’s prudent to investigate an unexpected deficiency — particularly to rule out these common causes:
1. Autoimmune Diseases
While vitamin B12 is mainly absorbed in the far reaches of the small intestine, its digestive process actually starts in the stomach. Our stomachs are lined with specialized cells whose proper functioning is necessary for downstream vitamin B12 absorption. The cells that produce stomach acid need to be working well enough to keep pH levels low enough so that B12 can be cleaved from the food proteins to which it’s bound. And another set of cells that produce a compound called “intrinsic factor,” which is a necessary co-factor for vitamin B12 absorption, also need to be functioning.
Autoimmune diseases that destroy these specialized cells, then, impair the body’s ability to absorb B12 from diet — these diseases are called atrophic gastritis and pernicious anemia. A simple blood test can clue your doctor into whether this may be the cause of your unexplained vitamin B12 deficiency.
2. Small Intestinal Bacterial Overgrowth
SIBO, a condition in which too many of the normal bacteria from your colon take up residence further upstream in your gut, causes all manner of digestive havoc — think gas, bloating and diarrhea, constipation, reflux, weight loss and nausea. A lesser-known side effect of SIBO, though, is vitamin B12 deficiency. This is because certain types of bacteria use up vitamin B12 for their own purposes, so if you’ve got too many of them hanging around in your small intestine, they can intercept the B12 you’ve consumed before your own body has the chance to absorb it.
If your unexplained vitamin B12 deficiency is accompanied by a side of miserable digestive system symptoms, then it may be worth asking your doctor to breath test you for SIBO.
3. Inflammation
Inflammation in the tail-end of your small intestine, called Ileitis, can have numerous causes. These include inflammatory bowel disease (Crohn’s disease), various types of infections, taking too many NSAID pain-relieving medications and many, many others. Ileitis from any cause, however, will impede vitamin B12 absorption and often cause a deficiency. Ileitis is often (but not always) accompanied by pain in the lower right quadrant of your abdomen, diarrhea or both — and both of which should merit a conversation with your doctor.
[See: 10 Questions Doctors Wish Their Patients Would Ask.]
4. Tapeworms, Surgeries and Other Causes
Other gastrointestinal causes of a vitamin B12 deficiency include tapeworms (admittedly rare in our part of the world) and surgeries that alter your digestive system anatomy. These include weight-loss surgeries and surgeries that have removed part of your small intestine — particularly the ileum (far end adjacent to the colon). It’s disturbingly common for people who have undergone such procedures to have not been informed of the risk of B12 deficiency associated with these procedures, and of the need to take high-dose sublingual supplements or regular injections.
Bottom line: If you’re diagnosed with a vitamin B12 deficiency, be sure to ask your doctor what he or she thinks the likely cause is. If there’s no obvious explanation, start looking for one!
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4 Overlooked Causes of Vitamin B12 Deficiency originally appeared on usnews.com
