NHS website - Blood tests for iron deficiency anaemia

[helvella]

Just happened to notice this paragraph when I was checking something else entirely.

Blood tests for iron deficiency anaemia

Your GP will usually order a full blood count (FBC) test. This will find out if the number of red blood cells you have (your red blood cell count) is normal.

You do not need to do anything to prepare for this test.

Iron deficiency anaemia is the most common type of anaemia. There are other types, like vitamin B12 and folate anaemia, that the blood test will also check for.

nhs.uk/conditions/iron-defi...

Anyone agree with me that FBC will NOT check vitamin B12 or folate anaemias?

I think that it can, under some circumstances, identify macrocytosis. But that is not always present, especially earlier on and even more so, when the patient is also iron deficient. Yes, I know RDW can then be checked, if it is done.

But, most importantly, the combination of plentiful folate and insufficient B12 will be missed.

If you agree, maybe contact the website people with feedback?

If I am completely wrong, please tell me!

[Ernest2]

Hi Helvella,

I've had many FBC in my time, also B12 and Folate (not so often) and I think they are separate tests but can be done at the same time. It would be good to test the entire population over a certain age and see how many are B12 deficient. Interesting what people think is an acceptable low B12 level.

Best wishes,

Ernest

[fbirder]

I suppose the statement that a FBC will check for B12 and folate anaemias is, strictly, correct. If there is anaemia present then a FBC should spot it, even if it means they have to look at the RDW and interpret it correctly.

No, a FBC will not always detect a B12 or folate deficiency, because anaemia may not be present.

That, I think, is the point that the NHS website should make clear.

I can’t find, at the moment, my reference that says anaemia is only present in some people with B12 deficiency.