Pernicious Anaemia Society

Can someone comment on these blood tests


I have been reading this site for a while now and consequently that is why we got my husband to have his bloods tested. Based on your information in your area even though his b12 is in range he would still be classed as low??? He has terminal stage four melanoma, diabetes and thyroid problems (caused by his treatment). He does very very well and was actually diagnosed stage four in 2007. He is currently showing signs of b12 deficiency. Unfortunately I find that as he has a terminal diagnosis the medical world put it down to his illness. Before we start panicking we want to look at the bigger picture. As he is on metformin, thyroxine and hydrocortisone I am convinced that it is his medication that is causing the problem with his b12. From his blood tests you will see he is also slightly anemic. They put him on iron tablets. They didn't warn us and we didn't think not to take with other meds. He has been taking them with his thyroxine and hydrocortisone which looks like the iron has been hindering their absorption. His results are as below:

Liver function test

Plasma total bilirubin 4 umol/L - <21

Plasma ALT level 14 IU/L - (10-45)

Plasma alk phosphatase level 82 IU/L - (30-130)

Plasma albumin level 33 IU/L - (32-50)

Renal profile

Plasma sodium level138 mol/L- (135-145)

Plasma potassium level 4.1mmol/L - (3.5-5.0)

Plasma creatinine level 75 umol/L - (64-104)

Plasma C-reactive protein - elevated but reduced on last test 37.3 mg/L

Serum vitamin B 12 204 Ng/L - (180-900)

Serum ferritin 77 microg/L - (20-300)

Serum folate 5.7 microg/L - (3.0-20.0)

Serum iron level 7 micromol/L - (14-31)

Serum transferrin 2.48 g/L - (1.8-3.6)

Transferrin saturation index 13.% - (16-50)

I am sure this will make sense to you guys so any comments, suggestions or anything!!!, I am sure would be most useful.

Thank you so much

2 Replies

B12 is in the grey range.

Serum B12 is not a test that can be used as a single indicator for B12 - its a measure of the amount in your blood- not of what is going on at the cell level which is what counts and people vary a lot in how the levels in their blood relate to what is happening at the cell level. The range is based on averages and tries to balance picking up people who aren't deficient but missing those who are. about 5% who aren't deficient have levels under the range. about 25% who are deficient have levels in the normal range - so other markers are important.

macrocytosis (larger rounder red blood cells) is a common symptom of B12 deficiency and can act as a marker but isn't present in about 25% of those who are deficient so still not a definitive marke. An iron based anaemia will tend to make red blood cells smaller so macrocytosis is unlikely to be a good marker in your husbands case.

symptoms are another marker but also overlap with other conditions - including diabestes, thyroid and iron deficiency - so also very problematic as a marker in your husbands case.

Metformin is known to interfer with the absorption of B12 and is a risk for B12 deficiency - but B12 deficiency is often missed because of the overlap with diabetes symptoms.

There are a couple of other markers that can be used when things are ambiguous - MMA and homocysteine are two waste products of cycles that use B12 and will be elevated if cells don't have enough B12 to recycle them - so you could ask if MMA could be done - given symptoms, B12 towards lower end of range and the risk of B12 deficiency from use of metformin.

Hope you manage to get the thyroid under control soon and get the iron back to where it should be as ruling those out might make interpreting what is happening with B12 easier.


Hi Nee22

I'm very sorry to hear of your husband's diagnosis. His B12 levels are indeed pretty low but in range. He is in the "grey area" where it is possible he will have symptoms at this level despite a "normal" range result.

I'm not a medic so I am not sure if his melanoma diagnosis may be behind his low B12 levels or not. Metformin, however, is one of the drugs that can interfere with B12 absorbtion and cause low B12 levels so his doctors should ideally be paying attention to the fact his levels are so low in range.

There are other tests that can be done (MMA and homosysteine) which may help determine if he is deficient at a biochemical level but these tests are not routeinly done and I'm not sure if results from these may be affected by his health issues. Pernicious anaemia is a leading cause of B12 deficiency and this is tested for by testing for anti-infrinsic factor antibodies. Sadly this test can give 40-60% false negative results so is not ideal!

It is hard to know what may be behind his symptoms as many of the health issues he has have similar symptoms - you both may well need to be quite persuasive to "encourage" the Doctors to consider treating him with B12. Maybe print out a copy of one of the symptom lists below (whichever fits his symptoms best) and mark off the ones he has and also print a copy of the UK treatment guidelines (providing you are in the UK!) and highlight any parts you think may be relevant (eg metformin etc) and discuss it with his doctors.

Symptom lists: pernicious-anaemia-society.... and

B12 treatment guidelines: pernicious-anaemia-society....

Also have a look at the pinned posts here (on the right hand side or down at the bottom if on a phone) for more information that may help too. The Pernicious Anaemia Society itself may also be able to offer more specific advice too if you are a member.

If you have any other questions ask away! :-) I wish you both all the best, take care.


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