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Dr.Mian, MD
Category: Health
Satisfied Customers: 399
Experience:  Diplomat American Board of Family Medicine
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Very low B12 level how concerned should I be

Customer Question

Since June I have been going through a series of blood test. My doctor has been doing so in order to check my low B12 reading. I have been supplementing with foliate acid every day. Today I went in for my second blood test reading. My doctor said my B12 levels are extremely low. They are at the level of a 80 year old vegan male. He said for some reason my body is not absorbing B12. He said I need to begin getting B12 shots. He wants me to go see a endocronologist to try to figure out the reason for my low B12 readings. What could be the reason for my low B12 readings? What are the side effect from low B12? What would you recommend me do from here? How does this effect your daily life how concerned should I be. I am 30 years old male.
Submitted: 8 years ago.
Category: Health
Expert:  Dr.Mian replied 8 years ago.

Hello Vitamin B12 is essential vitamin that is found in foods like meat,eggs, milk, etc and is absorbed in the small intestine with the help of a protein called intrinsic factor( released from stomach).

If there is gastric atrophy , it leads to low or no production of intrinsic factor and ultimatly the absorption of vitamin B12 is impaired which leads to low levels of B12 in the blood.


Low levels of B12 in body leads to many problems . most notable is megaloblastic anemia (low hemoglobin with bigger red cells) and also neurological problems.


There are several possible causes of low B12 like

Strict vegetarian diet Stomach problems.

Problem with absorption in small intestine.

Problem with pancreas

Problem with transport in the blood

Problem with B12 metabolism at cell levels

. Heavy prolonged alcoholism.

You need a complete work up in order to know the underlying cause behind your low B12.

Its low level in blood is associated with anemia( low hemoglobin) Neurological problems like paresthesias or numbness, weakness, gait problem etc. In advance stages it may also cause memory problems.

You should take B12 shots as advised by your physician.

Consume diet comprising of egs, milk, meat etc.

you can also take oral B12 in the form of multivitamins.


Have complete work up by endocrinologist.

In early stages specially treated with B12 shots, it should not effect your daily life.

But as long as you have anemia( low hemoglobin) because of B12 deficiency, you should not be involved in any sternous physical exercise.


Best wishes for your health.

Customer: replied 8 years ago.
Thank you for the reply and we will accept. I just have one last quick question.

I have had 2 blood test done and both times my b12 came back low...and I am scheduled to go see and endocrinologist.

However my doctor who is very thorough...said that most doctors probably wouldn't have caught it but b/c he dug deaper into my blood work he found it. My question is what would of happen if the doctor had not found it. I mean I am going to follow the doctors orders but should I be really concerned or scared now that I am diagnosed with this. I mean is there a chance that the endo will say everything is ok...or are the blood test that accurate. Also I have been working out very hard for 13+ years and I have never had any problems with strenous when I read you response to that I was puzzled.

I guess long story short...should this scare me at 30 years old!

Thanks and again I will accept your answer!
Expert:  Dr.Mian replied 8 years ago.

As I said earlier, B12 deficiency is asscoiated with two major problems.


1-Anemia with larger sized red cells

2-Neurological problems like paresthesia, gait disturbance, memory problem, nerve hyper sensations etc.


Once your body stores of B12 will be repleted preferrably with I/M injections, these problems disappear.


Sternous exercise during severe anemia can pose risk to the heart as congestive heart failure because of extra stress on the heart muscles. But it happens only in prolonged and severe cases.


One thing that came to my mind afterwards that there is a parasite called diphylobothrium latum or Fish Tape Worm , can also cause Vit.B12 defeciency.

I read it almost 15 years ago and your question reminded me of that.


Best wishes

Dr.Mian and 2 other Health Specialists are ready to help you
Customer: replied 8 years ago.
Real quick follow up question.

I got to thinking and I did not fast correctly before I did my bloodwork could this of caused an error in my b12 reading being low?

Expert:  Dr.Mian replied 8 years ago.

nice to hear from you .


fasting shouldnot have effected your vitamin B12 reading.


Vit b12 is stored in liver and is continously poured in blood to meet body needs.

Fasting or non fasting should yield same results.


best wishes for your health