Pernicious Anaemia Society
14,634 members10,427 posts

Low B12 with High Folate level - Significance?


I'm having difficulty in finding the significance, and effects etc, of having a low Vit B12 but a high Folate level,


165.3ng/L [197-770] along with high Folate Level ie >20 ug/L [4.6-18.7 ug/L] in Oct 2016

199.0 ng/L [197-770] with Folate level 17.5 ug/L [4.6-18.7 ug/L] in Feb 2017

Could someone, perhaps, explain the implications, significance, cause & effect please?

Many thanks


3 Replies

Hi JMN2017 I'm not a medically qualified person but as I understand it B12 and Folate work together. You need to have a "healthy" level of folate to process the B12.

Perhaps this will help:

Folic acid is crucial for proper brain functioning and plays an important role in mental and emotional health. It helps in the production of DNA and RNA, the body's genetic material, especially when cells and tissues are growing rapidly, such as during infancy, adolescence, and pregnancy.

Folic acid works closely with vitamin B12 in making red blood cells and helps iron function properly in the body. Vitamin B9 works with vitamins B6 and B12 and other nutrients in controlling the blood levels of the amino acid homocysteine.

Rich sources of folate include spinach, dark leafy greens, asparagus, turnip, beets, and mustard greens, Brussels sprouts, soybeans, beef liver, brewer's yeast, root vegetables, whole grains, wheat germ, bulgur wheat, kidney beans, white beans, salmon, orange juice, avocado, and milk. In addition, all grain and cereal products in the US are fortified with folic acid.

Vitamin B9 (Folic acid) University of Maryland Medical Centre


do you supplement folate at all.

I'm not aware of anything that would be worrying about the folate levels you have.

Low levels in blood are either going to be the result of little or no B12 in your diet or an problem with the mechanism the body uses to absorb B12 which is very specialised so it is quite possible just to have problems with B12.

If I remember your earlier post properly you are on metformin which is a possible source of absorption problems. This affects 40% of metformin users and can result in B12 deficiency.

Folate isn't stored elsewhere in the body as far as I am aware so the amounts in your blood are likely to be dietary related - indicating that your diet is rich in folate. It will stay in blood until it is either used or removed and passes out in your urine. folate is used in absorbing and processing B12 so if you haven't got enough B12 to process and use it is possible that this might lead to slightly higher levels in your blood.

High levels of folate can also mask macrocytosis caused by B12 deficiency - meaning that your red blood cells look normal for longer than they would do otherwise so if your GP is looking for macrocytosis as a defining characteristic of B12 deficiency they are less likely to find it ... However, as 30% of B12 deficient patients present with neurological and neuro-psychiatric problems long before any sign of macrocytosis appears they shouldn't be ruling out B12 deficiency just because macrocytosis isn't present


Hi Gambit62 and @clivealive

My apologies but, for some reason, I didn't respond to your reply and have just come across the thread again.

To answer your queries, no, I'm not taking any suppliment now although I was taking Multivit tabs (including iron) as suggested by GP some years ago. I stopped taking these vit tablets when the first of the B12 / Folate results came through as I felt it would be interesting to see how they might change by the time of the re-test at 3 months later, ie the 2nd set of results in my original post of this thread.

Secondly, yes, you're quite right, I'm also taking 2gm Metformin daily and have been for several years.

In addition to the Metformin, I also take Ranitidine twice a day for 'gastritis' (am symptomatic with gastric pain after a while without/reduced tablets

And another factor, I'm on Levithyroxine for Hypothyroidism but I've never been told / mentioned Hashimoto's so I'm not sure of what cause, and no family members with thyroid issues.

My father was on B12 injections. I believe because of anaemia/breathlessness symptoms which were very much helped by these injections.

Thanks for the links and info, clivealive

Very useful

1 like

You may also like...