# Metformin and vitamin B12 absorption

**URL:** <https://forum.fudiabetes.org/t/metformin-and-vitamin-b12-absorption/279>\
**Category:** Type 1 & LADA\
**Tags:** metformin, glucophage, vitamins, anemia, type-2\
**Created:** [March 30, 2017, 9:27pm UTC](https://forum.fudiabetes.org/t/metformin-and-vitamin-b12-absorption/279 "2017-03-30T21:27:34Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![lh378](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/lh378/32/601_2.png) [@lh378](https://forum.fudiabetes.org/u/lh378)\
**Post date:** [March 30, 2017, 9:27pm UTC](https://forum.fudiabetes.org/t/metformin-and-vitamin-b12-absorption/279/1 "2017-03-30T21:27:34Z")

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I recall reading somewhere that metformin could interfere with vitamin B absorption. Any thoughts, comments?

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**Author:** ![Michel](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/michel/32/387_2.png) [@Michel](https://forum.fudiabetes.org/u/Michel)\
**Post date:** [March 30, 2017, 9:35pm UTC](https://forum.fudiabetes.org/t/metformin-and-vitamin-b12-absorption/279/2 "2017-03-30T21:35:20Z")

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I read the same thing, but I don’t quite know what to think at this stage. Have a look at this article from 2010, which implies that this is established:

[Metformin-induced Vitamin B12 Deficiency Presenting as a Peripheral Neuropathy](http://www.medscape.com/viewarticle/719043_3)

But this 2014 article from the [Joslin Diabetes Center](http://www.joslin.org/) presents a less absolute view:  
[Should You Take B12 Supplements if You Take Metformin?](http://blog.joslin.org/2014/06/should-you-take-b12-supplements-if-you-take-metformin/)

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**Author:** ![britt\_j](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/britt_j/32/55_2.png) [@britt\_j](https://forum.fudiabetes.org/u/britt_j)\
**Post date:** [March 31, 2017, 4:38pm UTC](https://forum.fudiabetes.org/t/metformin-and-vitamin-b12-absorption/279/3 "2017-03-31T16:38:58Z")

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I suspect this is yet another situation where genetics makes all the difference…

“Long-term Metformin Use and Vitamin B12 Deficiency in the Diabetes Prevention Program Outcomes Study”  
Vanita R. Aroda et al; J Clin Endocrinol Metab (2016) 101 (4): 1754-1761. DOI: [https://doi.org/10.1210/jc.2015-3754](https://doi.org/10.1210/jc.2015-3754)  
Published: 01 April 2016 \>\>

“Conclusions: Long-term use of metformin in DPPOS was associated with biochemical B12 deficiency and anemia. Routine testing of vitamin B12 levels in metformin-treated patients should be considered.”

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Mayo Labs: Pernicious Anemia Cascade \>\> “Clinical Information: Vitamin B12 deficiency can be caused by many factors, one of which is pernicious anemia, a condition resulting in deficient production of intrinsic factor in the parietal cells of the stomach. Intrinsic factor is a protein that is needed to assist in the absorption of vitamin B12 into the small intestine. Vitamin B12 is converted into adenosylcobalamin, which converts L-methylmalonic acid to succinyl coenzyme A; hence, a decrease in vitamin B12 absorption in the intestine can cause an excess of methylmalonic acid within the body.”

FMI:  
[http://www.mayomedicallaboratories.com/test-catalog/Clinical+and+Interpretive/83632](http://www.mayomedicallaboratories.com/test-catalog/Clinical+and+Interpretive/83632)

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SA:

> **[FUDiabetes](https://forum.fudiabetes.org)**
>
> a community for unlimited diabetics

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**Author:** ![Michel](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/michel/32/387_2.png) [@Michel](https://forum.fudiabetes.org/u/Michel)\
**Post date:** [April 1, 2017, 6:17am UTC](https://forum.fudiabetes.org/t/metformin-and-vitamin-b12-absorption/279/4 "2017-04-01T06:17:46Z")

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I have just read all these references again, but I am still not getting the feeling that the evidence of interference with B12 absorption is as clearly-cut as it could be. Are you?

I am guessing, though, that Lilian is thinking in terms of whether metformin users should consider upping their consumption of B12 supplements.

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**Author:** ![lh378](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/lh378/32/601_2.png) [@lh378](https://forum.fudiabetes.org/u/lh378)\
**Post date:** [April 2, 2017, 1:15pm UTC](https://forum.fudiabetes.org/t/metformin-and-vitamin-b12-absorption/279/5 "2017-04-02T13:15:01Z")

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@Michel, precisely.