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San Jose, CA
A 33-year-old female asked:

If you have a vitamin b12 deficiency how long does it take to replenish it with over the counter supplements?

1 doctor answer1 doctor weighed in
Dr. Daniel Ziegler
Emergency Medicine 32 years experience
Depends: Depends on why you have a B12 deficiency in the first place. Some people, either from gastric bypass surgery or other reasons dont produce intrinsic factor which is made in the stomach and is necessary for us to absorb B12 that we have taken orally. In those cases it takes a shot. In any case 1% of oral B12 is passively absorbed. Once absorbed our bodies are efficient replenishing and storing it.
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Last updated Jun 29, 2019


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