Before we list all stages of B12 deficiency, let’s get the basics right:
B12 is the only vitamin that contains a trace element, cobalt, and it is why the vitamin is also called cobalamin. You won’t find B12 in plants, nor can animals produce it. What occurs, is that both bacteria and animals feed on cobalt-rich sources, like grass. That bacteria ends up multiplying in the gut of these animals, producing B12. The rest of the world’s creatures, including us, get our vitamin B12 by eating these prey animals.
Your body can store B12 for several years. Only when these stores are emptied will you notice any symptoms, and you’ll begin to go through four stages of B12 deficiency, the final of which you will start to see weird neurological signs. Permanent damage can then take place, because the nerve system is exceptionally vulnerable to a lack of B12.
Now, what exactly are the stages of B12 deficiency, and what signs and symptoms accompany them? The diagram below is an adaptation of Dr. Herbert’s proposed model, describing the biochemical, metabolic, and clinical changes that occur as B12 repletion progresses to depletion, and eventually to clinical vitamin B12 deficiency:
The 4 Stages of B12 Deficiency In Detail
Here’s a more detailed description of all stages:
- Stage 1: Early Serum Depletion
This is the beginning of the B12 deficiency. You won’t feel as if anything is wrong at all, because there are no noticeable symptoms. However, serum blood levels of B12 begin to drop, the majority of which is likely to be active B12 (holoTC).
- Stage 2: Cellular Depletion
As the deficiency progresses, cellular depletion of B12 begins to take place, and cellular dysfunction sets in. Like in the previous B12 deficiency stage, there are no clear signs yet, which is why it’s so easy to miss this stage as well.
- Stage 3: Damaged Metabolism
There are now discernible changes in the blood. Levels of MMA (methylmalonic acid) and homocysteine rise, because the body uses B12 in order to convert them to other structures. At this stage, you may experience gastrointestinal symptoms like abdominal discomfort, indigestion, diarrhea, and bloating.
This stage does not yet show full anemia, which is exclusive to the final stage of B12 deficiency. However, anemia signs like weakness and lethargy, and neurological symptoms like tingling and numbness, may begin to appear. This represents the entry into stage 4, which is when things turn from bad to worse.
- Stage 4: Clinical Damage
Hemoglobin levels drop and anemia is apparent, causing lethargy, breathlessness, paleness, and weakness. Macrocytosis (enlarged red blood cells) is present. Speaking of, doctors often rule-out B12 deficiency when macrocytosis is absent, which is a big mistake. It only appears at the final stage, when it may already be too late.
Stage-four is the most severe stage of B12 deficiency. Without prompt treatment, the nervous system is at great risk for permanent damage, damage such as which the doctors will describe as Alzheimer’s, Parkinson’s, and other nerve-related ailments. In severe cases, complete paralysis of any part of the body may occur, because of damage to the nerves that connect to that particular region.
An early sign of stage-four B12 deficiency is myelopathy (degeneration of the spinal cord). If detected in time (that is, in its very beginning, where it manifests as tingling sensations), it is reversible. Unfortunately, a person usually pays enough attention to the symptoms when some degree of damage has already been done.
At this stage, the nerve damage that occurs is really the result of damage to the myelin and nerve axons, which are being destroyed in the white matter of the spinal cord. If you’re at stage four, don’t wait another day, and start injecting B12 (on a daily basis). B12 shots will help you prevent further damage. They work.
Other early, mild symptoms of this stage of vitamin B12 deficiency include fatigue, depression, anxiety, hair loss, numbness, and poor memory and cognition. In fact, at this stage the whole spectrum of B12 deficiency symptoms may be seen (as well as pernicious anemia symptoms, because PA is just a special form of B12 deficiency).
What to Do?
If you’re even remotely suspicious of being deficient, start treatment right away. There is no risk – B12 isn’t toxic, even at enormous amounts. It’s not worth delaying treatment, because of the inherent risk of reaching the fourth, final stage of B12 deficiency. Yes, do have the proper screening tests, but begin treatment as you’re waiting for diagnosis.
You’ll know when you’re at stage 3-4 when your levels of total-B12 are low (though sometimes they’re not), and when your MMA and homocysteine levels rise. In addition to these, if you display nerve-related and anemia symptoms, you’re definitely at stage 4.
At advanced stages, we highly recommend injecting methyl B12, because this form of B12 takes care of two problems simultaneously. It saturates your cells with B12, and it reduces your dangerous levels of homocysteine. Therefore, it’s our preferred form.
And please, don’t wait. Get the tests done, and begin treatment. Remember, the nerve system doesn’t have the ability to fully regenerate itself once damaged, and the safe window for intervention is very narrow and easy to miss.
Good luck.