How to test B12 levels properly and determine whether you suffer from a lack of B12 or not? Unfortunately, many B12 deficiency cases are discovered too late, or worse, are entirely missed. Doctors often misdiagnose it as another condition, and as a result patients end up with lifelong neurological damage that could have been easily prevented if caught on time. Therefore, the early diagnosis of B12 deficiency is crucial, and you should make sure your doctor is performing the process properly.
Vitamin B12 Deficiency Diagnosis Issues
First, a word on the common issue of misdiagnosis. When B12 deficiency starts to affect the nerves, doctors tend to misdiagnose it as another illness with similar symptoms, or blame a co-existing condition which may actually be the result of B12 deficiency:
- Multiple sclerosis
- Bipolar disorder
- Diabetic neuropathy
- Chronic fatigue syndrome
- Chronic pain disorder
- Functional neurological disorder
- Myalgic encephalomyelitis
- Irritable bowel syndrome
- Optic neuritis
- Folate deficiency
Why is misdiagnosis so common?
- Extremely poor knowledge among doctors, leading to symptomatic people not being tested at all. Often, a patient complaining about depression will be prescribed antidepressants instead of being tested for B12 deficiency. Doctors just do not test for B12 deficiency, and in most countries you have to ask your doctor to do it. Health care professionals simply assume meat eaters get enough B12 from their diet, so they don’t even bother to check for B12 deficiency. However, most cases of a lack of B12 are the result of malabsorption, rather than low consumption.
- Even when doctors do test for B12 deficiency, there are some major problems with the regular blood test, as you’ll see in a moment.
- Before testing for B12 levels, doctors often look for macrocytosis (enlarged red blood cells), but this is the last, advanced stage of B12 deficiency. Only about 60% of B12 deficiency patients show them, and at that point, some of the damage can’t be reversed. Even neurological signs and symptoms – which indicate severe B12 deficiency – may be present despite having normal red blood cells.
- Doctors tend to assume that the neurological effects of B12 deficiency, like tremors, falling, or cognitive decline, are all part of normal aging. Therefore, elderly people, who are at the highest risk for B12 deficiency, aren’t even tested. Sometimes they don’t blame the symptoms on aging, but on other co-existing medical conditions. Similarly, mental health patients or pregnant or breastfeeding women, groups that are at real risk of B12 deficiency, aren’t tested as well.
- It is probable that research simply tends to gravitate towards where the potential for profit is. Simply put, there’s more money to be made treating B12 deficiencies with their resulting neurological damage that demands complex medicines, rather than preventing them in the first place. It’s only natural that research would go that direction. This may lead to doctors being so unbelievably misinformed.
Vitamin B12 Deficiency Tests
So, how do you test for B12 deficiency properly?
Here are the tests available, and how effective they are.
Serum Vitamin B12 Blood Test
The most common blood test for B12 is what doctors rely on most of the time. Which is very unfortunate, as the test is far from accurate. That’s because:
- It accounts for inactive B12 analogues as well. The test measures the total amount of B12 in the blood, not distinguishing between active B12 (transcobalamin II) and inactive analogues (transcobalamin I and III). Inactive B12 may represent as much as 80% of your blood levels. So even though your results may look normal, you may still be deficient if a large portion of your B12 is inactive, which is unusable.
- The blood test for B12 deficiency doesn’t record what’s going on at the cellular level. Blood levels of B12 are not enough – we want to know what’s happening inside the cells, where it actually matters.
- In most countries, the normal B12 level range is too low. Some countries accept levels as low as 100. As a result, doctors often miss and refuse to treat desperately deficient patients, even when they show obvious symptoms. These doctors should know that B12 deficiency begins to appear in the cerebrospinal fluid below blood levels of 550. This is why Japan now treats with B12 shots anybody with levels lower than 500. Their willingness to treat levels considered “normal” in the rest of the world, may explain their low rates of dementia diseases. In most other countries, if you had levels of, say, 400, you’d be considered healthy. Why would the difference of being or not being diagnosed with B12 deficiency depend on your geography?
- It’s possible that a person could be suffering from B12 deficiency even though his B12 blood test shows a very high number. Conditions such as liver disease or cell death (for example, due to cancer, which breaks down tissues), may release B12 back into the blood circulation, tricking the test into thinking B12 stores are large.
- The typical B12 test uses a competitive binding luminescence assay. It gives false high results in 22-35% of patients, depending on the machine.
In short, the serum B12 level test doesn’t tell you the whole story. Use it as an indicator, but nothing more than that. Here are better B12 deficiency diagnostic tests:
HoloTC (Holotranscobalamin II) – Active B12 Test
One of the best tests is HoloTC (Holotranscobalamin II). It only measures levels of active B12 in the blood. We predict that it will one day replace the regular test entirely, because there are often big gaps between the total blood levels of B12, and levels of active B12. This test should be a first-line diagnostic tool, as low levels may point to B12 depletion at the cellular level. Unfortunately, most hospitals don’t offer this test yet.
But, you can do this test privately at Viapath.
Methylmalonic Acid (MMA or uMMA) Test
One of the core functions of vitamin B12 is that it helps convert methylmalonyl-CoA, one of the forms of MMA, into succinyl-CoA. Therefore, when you’re deficient in B12, your MMA levels will increase in your blood and urine. In fact, MMA is high in ~95% of B12 deficiency cases. However, high levels of MMA could also be the result of renal failure, small bowel bacterial overgrowth, or hemoconcentration.
But, if plasma levels are higher than 0.75 µmol/l, it’s most likely to be B12 deficiency. The MMA test is a phenomenal test, but it’s not very popular, because it uses the expensive gas chromatography mass spectrometry (GC-MS). You may be able to order an MMA test as a follow-up to a blood test showing B12 in the lower end of the normal range. In that case, having high MMA levels will be confirmatory.
If you can’t get your doctor to prescribe an MMA test, you can order a urinary MMA (uMMA) test directly from the founder of the test, Dr. Eric Norman. This version is even better than the serum one, because B12 deficiency patients with neurological damage excrete significantly more uMMA than those without damage. Therefore, uMMA tests can predict your path toward lifelong neurological damage. The test has an impressive 99% accuracy, making it confirmatory.
The only caveat is if you have kidney disease. In that case, you may get false high levels with the serum MMA test, or false low levels with the uMMA test, because it’s the kidneys’ job to flush out the MMA in the urine. When they don’t operate as intended, MMA may build up in the blood. Also, serum MMA is raised in conditions other than B12 deficiency. Thyroid disease, intestinal bacterial overgrowth, pregnancy, or a rare infant’s genetic disorder called methylmalonic acidemia, may all lead to high serum levels of MMA.
For these reasons, we like Dr. Eric Norman’s uMMA test the most. If your uMMA levels are high, you most likely suffer from B12 deficiency.
uMMA / MMA Test Results
If you did the uMMA test, anything higher than 3.60 mmol/mol creatinine indicates B12 deficiency. If you did the serum MMA test, then it is anything higher than 0.04 nmol/mL. Do note, your MMA levels do not necessarily reflect the progression of B12 deficiency. Also, there may be a high variation in MMA levels when measured over time.
Plasma Total Homocysteine (tHcy) Test
The body uses methylcobalamin, one of the native forms of B12, to convert homocysteine back into methionine. Therefore, the homocysteine test is a good extra tool to determine your true B12 status. Even if your B12 blood levels look normal or high, high homocysteine levels may indicate a functional deficiency or decreased capacity to utilize methyl B12. Note, high homocysteine levels could also be the result of low B6, folate, renal failure, or hypothyroidism. This test must be carried out within two hours of sampling the blood, which must be cooled during that time.
MCH / MCHC
Other useful tests are the MCH (mean corpuscular hemoglobin) and the MCHC (mean corpuscular hemoglobin concentration), which check how much hemoglobin you have per red blood cell. MCHC also accounts for the cell volume. High levels in these tests may indicate B12 deficiency. They’re not conclusive, but can be used as an extra tool.
B12 Deficiency Shilling Test
The Schilling test is now considered obsolete, and is no longer available at most medical centers. It was used to find the cause of your B12 deficiency – whether you can absorb B12 normally or not, and if not, then why – after your deficiency had already been confirmed. For that reason, it was also called the “vitamin B12 absorption test”.
Groups at High Risk for B12 Deficiency:
Elderly individuals. Around 20-30% of people above the age of 50 develop atrophic gastritis, a disease in which B12 absorption is impaired. This is confirmed by numerous studies.
Children with developmental delays. It can take years before B12 deficiency develops in adults, because our body stores B12 for future use. Children, in contrast, don’t have the rich stores adults have.
Pregnant and breastfeeding women. Fetuses and breast-fed infants drain nutrients from their mothers. These women should be taking extra B12.
Women with post-natal depression or a history of infertility or miscarriages. These women should be tested immediately for B12 deficiency.
Vegetarians and vegans. Every vegetarian should supplement with B12. Up to 80% of long-term vegans are B12 deficient.
Gastrointestinal surgery patients. If you had any surgery where part of your stomach or ileum was removed (including surgeries for weight loss purposes), you’re likely to need a lot more B12 than before.
People on certain medications. This includes proton pump inhibitors, H2 blockers, antacids, metformin, or any other medication which can interfere with B12 absorption. Those undergoing chemotherapy or using nitrous oxide (laughing gas) regularly should also be supplementing with B12.
Anyone with gastrointestinal diseases. Anyone diagnosed with a disease that may cause malabsorption of nutrients, for example Crohn’s, ulcerative colitis, irritable bowel syndrome, and celiac. Also, misdiagnosis is common. We recently had a woman come to us with an unresolved Crohn’s disease. She’s been on medication for years. Turns out, she never had Crohn’s. She simply had B12 deficiency and pernicious anemia, because our B12 shots combined with our diet led to 100% remission in her symptoms.
Heavy smokers or alcoholics. These toxins may deplete B12 stores.
People with a history of eating disorders.
How to Diagnose B12 Deficiency?
So, how do you test for and diagnose B12 deficiency?
As you see, it is not as straightforward as some doctors think.
The serum blood test isn’t reliable enough, so you should only use it as an indicator. You may have very high numbers of B12 in the blood and still be deficient. Similarly, homocysteine may rise not just in the absence of B12, but in the absence of B6, B9 (folate), and magnesium as well. Likewise, MMA may rise in the presence of kidney disease, thyroid disease, intestinal bacterial overgrowth, pregnancy, or the genetic disorder called methylmalonic acidemia (afflicting infants).
So, what do you do?
The obvious option is to combine them. If your B12 levels are lower than 500, and if your MMA and/or homocysteine levels are high, then you’re very likely suffering from vitamin B12 deficiency. However, If you did both tests and only homocysteine levels were elevated (but not MMA), then you may actually have folate deficiency. If both MMA and homocysteine levels were fine, chances for B12 deficiency are very slim.
When is the chance for B12 deficiency very high?
When your blood levels of B12 are extremely low, and/or when Dr. Eric Norman’s uMMA test results show a high number. The uMMA test is as confirmatory as it gets. If your uMMA levels are high, you almost certainly suffer from B12 deficiency.
We recommend to test for folate (vitamin B9) and ferritin (iron storage), and to do a full blood count. This is because B12 and folate need each other, and optimal levels of iron are just as important as optimal B12 levels. The importance of this can’t be stressed enough.
Also, before having any vitamin B12 deficiency test, do NOT supplement with B12 for at least 72 hours, because it could skew your results. Some labs may prefer not to draw a blood sample within two weeks of a B12 injection.
And if you suspect your B12 deficiency is the result of pernicious anemia, go and do the necessary pernicious anemia tests, which will check the presence of specific antibodies. Even in the absence of anemia, anybody with unexplained low levels of B12 should be tested for PA.
Perhaps the primary question should be, then, how obvious are your symptoms?
To quote NEQAS:
In the event of any discordance between clinical findings of B12 deficiency and a normal B12 laboratory result, then treatment should not be delayed. Clinical findings might include possible pernicious anaemia or neuropathy including subacute combined degeneration of the cord. We recommend storing serum for further analysis including MMA, or holotranscobalamin and intrinsic factor antibody analysis, and treating the patient immediately with parenteral B12 treatment.THE UNITED KINGDOM NATIONAL QUALITY ASSESSMENT SCHEME FOR HAEMATINIC ASSAYS
This brings us to the central point.
Best Vitamin B12 Test: Your Symptoms
As you can see, the NEQAS now recommends to look at the clinical picture, and give patients vitamin B12 injections based on their symptoms alone. This is because the risks of delaying treatment and waiting for B12 deficiency diagnosis, disproportionally outweigh the benefits of doing so. The message is, if you show clear symptoms of B12 deficiency, start injecting B12 right away. Ask your doctor for a trial of methylcobalamin B12 shots. If they refuse, you can buy it here and take control of your health.
Remember, vitamin B12 has no toxicity levels, and you can’t overdose. There is no risk involved. Anything your body doesn’t need goes out through the urine in no time. So, if you show clear symptoms, don’t put off treatment waiting for diagnosis.
If you suspect you may be suffering from B12 deficiency, then take action now. Disregard blood levels of B12 entirely, and go by symptoms alone. There’s a short window of opportunity for effective intervention, especially to those with neurological symptoms. The risk is too high. Wait long enough, and you end up with severe, lifelong neurological damage. When you suffer from B12 deficiency, the myelin around your nerves gradually and most likely irreversibly strips off. Injecting B12 early (and daily) may save your nerve system, life quality, and sanity. B12 shots are the best way avoid major nerve damage.
So, inject daily for at least three months, and then gauge improvement. If you feel much better than before, you’re very likely to have had B12 deficiency. Keep injecting until you find the cause. If it’s pernicious anemia, you’ll likely have to inject for life. If not, then injecting may be temporary, until you find the cause and treat it accordingly.
Best of luck.