Vitamin B12 deficiency is a very sneaky condition that presents in multiple different ways. The signs and the symptoms of low vitamin B12, ranges from physical changes to even psychological changes. The reason why I'm making this post is because, it's so important to identify B12 deficiency as early as possible, as low B12 can lead to serious health problems if left untreated.
What's challenging about this is a lot of these signs are very easy to miss, and the symptoms overlap with other conditions. So they can be very easily missed even by your doctor. Therefore, it's important to educate yourself and learn how to identify B12 deficiency as early as possible.
In this post, I'll go over all the important warning signs of vitamin B12 deficiency that you should never ignore. Because of this overlap with other conditions, I'm also going to discuss which group of people are at increased risk of developing B12 deficiency.
There are many other groups of people that are at an increased risk for developing vitamin B12 deficiency. So if you have any of the symptoms I described in this post, and you do fall in the high risk category, then you should definitely make sure to have your vitamin B12 levels checked out. And if you have family members or friends who you think will find this post valuable, share it with them, as it's a very important topic on a condition that often goes untreated.
Also, if you've been dealing with vitamin B12 deficiency, and you present it with a sign or a symptom that I did not cover in this post, let me know in the comments below so we can all learn from each other's experiences.
Why Vitamin B12 is Important
The reason why vitamin B12 is so important is because it's an essential cofactor that your body needs to make DNA and it's extremely important in cell metabolism.
So if these processes are disrupted, it leads to a whole cascade of downstream effects on your energy production, and your central nervous system, and your blood cell production.
1. Easy Fatigue and Low Energy
The very first thing you may notice, even with a very mild B12 deficiency, is fatigue or low energy. This fatigue happens for two reasons;
One, your body becomes less efficient in energy metabolism and two, inadequate B12 levels lead to anemia, or a condition where you do not have enough red blood cells and you need red blood cells to deliver oxygen to your organs.
But there are thousands of reasons why people get fatigue or low energy, but the fatigue that we get from B12 deficiency is usually exertional fatigue. So it's the fatigue that comes on pretty quickly, and it's pretty short-lived, and it comes on even after a mild physical activity, or even mild mental strain. Another thing to watch out for, is this fatigue may also come with shortness of breath, or even heart palpitations when you're trying to exert yourself.
So it's not so much feeling of tiredness or having low energy, but it's more so fatigue with any kind of physical or mental exertion.
2. Headaches
Another common presentation of vitamin B12 deficiency is headaches, especially migraine headaches. There are studies in children that show that headaches was the most commonly reported symptom of vitamin B12 deficiency.
There are other studies that show that serum vitamin B12 levels were significantly lower in migraine patients than in healthy subjects. So we don't actually really know why there's such an association between B12 and headaches or migraines. Some speculate it could be due to the underlying anemia or nerve disruption, which I will talk about in just a moment.
There're some speculations that B12 deficiency and the associated high levels of homocysteine is what causes endothelial cell damage by increasing the levels of free oxygen radicals.
3. Painful Tongue Swelling
Next, another sign of B12 deficiency is painful tongue swelling or inflammation of the tongue, which is also called glossitis. This tongue inflammation is usually present in about 25% of B12 deficiency cases.
People may describe it as sort of a burning sensation or itching, or even loss of taste or having metallic taste on the tongue. Now, there are many other reasons why somebody can develop glossitis or tongue inflammation, things like iron deficiency, anemia, or viral infection or a fungal infection.
There's also a lot of medications that can cause glossitis, medications like albuterol or oral contraceptive pills. So it's not always vitamin B12 deficiency that causes this and if you get this, you definitely need some other tests and labs to rule out other causes.
4. Skin Changes
Next up, another sign of vitamin B12 deficiency is skin changes and more specifically, you may get pallor or pale skin, which is once again caused by the underlying anemia. Another very important skin changes that occurs due to vitamin B12 deficiency is thickening and darkening of palm and soles, this is almost the most commonest occurrence in all patients with B12 deficiency.
In more severe cases, B12 deficiency may actually cause jaundice or yellowing of the skin or yellowing of the whites of the eyes and this happens due to the bone marrow having trouble producing healthy red blood cells, which eventually leads to the destruction of immature red blood cells, that in turn causes the buildup of bilirubin. Bilirubin is just a waste material created when the body breaks down blood cell byproducts.
5. Numbness and Tingling of Hand and Feet
Another important sign of vitamin B12 deficiency is numbness and tingling of your feet and your hands. You may also feel like burning or pins and needles sensation.
So medical word for that is neuropathy, and this neuropathy can be similar to diabetic neuropathy. But in the case of diabetes, it's the high blood sugar that damages the nerves.
So because of this overlap, neuropathy due to B12 deficiency is very often misdiagnosed as diabetic neuropathy in people with diabetes. And in some cases, you can have both the diabetic neuropathy and a separate neuropathy caused by B12 deficiency.
I actually have very low threshold to check B12 levels in those cases as both the diabetes and the use of common diabetes medications like metformin can put you at a higher risk for developing B12 deficiency.
By the way, it's not just metformin that can lead to B12 deficiency. There are a few other medications that you need to watch out for. And I'm going to talk about them later in this post.
The nerve damage happens because vitamin B12 is directly responsible for producing myelin or a protective layer around the nerve and this myelin shields the nerves against damage. So vitamin B12 deficiency leads to the loss of this protective nerve barrier.
On top of that, when your body does not have enough vitamin B12, it also causes a buildup of methylmalonic acid, which can be toxic and can cause further damage to the neurons. Now, as this nerve damage progresses, it can cause even more neurological impairment. You may start seeing things like poor coordination and abnormal balance and even abnormal reflexes.
In some cases, it may even affect your gait or you may have difficulty in walking, and in very severe cases of longstanding B12 deficiency, you may even get painful vision loss, which is caused by the damage and inflammation of the optic nerves. On top of that, if your vitamin B12 deficiency goes untreated for too long, you can even see psychotic features like hallucinations and paranoia and even depression.
In some people, it can even progress to dementia. Now, the good news is the damage to the nerves that is caused by low B12 can be reversed with early and aggressive treatment. So that's why it's so important to identify this as early as possible.
6. Cognitive Impairment
Another important sign to watch out for is cognitive impairment, which can present as poor memory or difficulty concentrating. There's cohort studies that noted that low plasma B12 and folate levels were associated with worse cognitive function, and there was another study that was a cross-section analysis of 39,000 people that found that low vitamin B12 was associated with poor memory in men.
How Did You Know You Vitamin B12 Deficiency?
Because these signs and symptoms overlap with so many other conditions, how do you know whether you should be worried about a B12 deficiency? Well, to start, you can always have your levels checked out. But what's confusing about that is if your B12 level comes out as normal, you may still have a deficiency as there's different gradients to what's considered normal for different people, and in some cases, you may have a true vitamin B12 deficiency despite stone-cold normal B12 levels, and that's called a functional B12 deficiency.
So in my practice, if I'm concerned about a B12 deficiency, I usually combine that B12 test with other tests like MMA or methylmalonic acid. And I check a few other tests to make sure we get the true diagnosis. But the workup for B12 deficiency and all the additional tests involved is a huge topic on its own. I'm going to make a separate video on that later.
Now, since the diagnosis is not as straightforward as checking your B12 levels, you also need to consider if you are someone who's at a greater risk for a B12 deficiency, and in those cases, an argument can be made for a more aggressive treatment, even if your blood tests are borderline or normal.
Risk Factors of Vitamin B12 Deficiency
So what are the risk factors? Well, you may be at a much higher risk for deficiency if you take certain medications that interfere with the absorption of B12, and the most common medication I see that does that is metformin. And just four months of taking metformin can put you at risk for developing B12 deficiency. So I would recommend supplementing with both B12 and folate if you do take metformin long-term.
Another medication that will put you at risk for a B12 deficiency are histamine H2 blockers, which are common over-the-counter heartburn medications like ranitidine, famotidine or cimetidine. People that suffer from heartburn may also get put on another class of medication called proton pump inhibitors or PPIs. So these would be drugs like omeprazole or Prilosec and esomeprazole or Nexium, and another common one is pantoprazole or Protonix. Now, with these heartburn or reflux medications, we usually don't have to worry about B12 malabsorption unless you've been on these medications continuously for at least 12 months.
Next, another thing that can put you at risk for developing B12 deficiency is if you ever have bariatric surgery like gastric sleeve or a gastric bypass, and the issue there is actually twofold. So first, the resection of the stomach or any surgery involving the small intestine may just anatomically interfere with your absorption of B12.
Second issue is these surgeries resect the portions of the stomach called the parietal cells, and these parietal cells are important because they produce a very important protein called intrinsic factor. This protein plays a crucial role in both the transportation and absorption of vitamin B12.
If we don't have that intrinsic factor, we just cannot absorb vitamin B12 into our bloodstream. In fact, there's a rare autoimmune condition called pernicious anemia where your own immune system attacks these intrinsic factor proteins and they make it difficult for them to bind to vitamin B12, which prevents B12 from being absorbed in the small intestine.
The next risk factor is age, as we get older, the likelihood of developing a B12 deficiency goes up quite a bit. So how old are we talking about? Well, being 75 and above definitely puts you in the higher risk category, and I would actually lower that age to 60, as it's estimated that up to 20% of people in the U.S. over the age of 60 are deficient in vitamin B12.
Lastly, the most well-known reason for B12 deficiency is if you're a vegan or a strict vegetarian to where you don't consume any animal products like meat or dairy products, which is where most people are able to get their B12.