Log in
Thyroid UK
91,714 members106,018 posts

folic acid and vit b12

Hi there,

My son has been showing some symptoms of b12 deficiency lately. I realised that his b12 was low but in range when last tested about a year ago so it is quite possible that it has decreased further. He has been on folic acid for a while as folates were low, he also still has a low vit D although he has been supplementing for some months. I have now discovered that folic acid masks macro blood cells indicating pernicious anaemia and we would like to change to methylfolate. My question is, does methyfolate also mask these increases in blood cell size too? I know if we supplement with b12 now it will affect a test for pernicious anaemia, but he is feeling poorly and I don't know when another blood test will happen as we have to wait a while in order to see the same supportive doctor.

I would be grateful for any comments on latest blood results from a full blood count

red blood cell count 4.85 (4,50 - 5.50)

haemaglobin estimation 151g/l (130 - 170)

haematocrit 0.41L/L (0.40 -0.52)

mean corpuscular volume (MCV) 85.2Fl (83.0 - 100.0)

mean corpuscular haemoglobin (MCH) 31.1pg (27.0 - 32.0)

! mean corpusc Hb conc. (MCHC) 366 g/l (315 - 345)

He is on T4 alternatively daily 75 and 100mg. He is slightly overdosed at present.

TSH 0.09mIU/L (0.27 - 4.20)

FT4 19.5pmol/L (12.0 - 22.0)

FT3 6.8pmol/L (3.9 - 6.7)

Many thanks

5 Replies

Hi Rosy, it's such a worry when our children are ill. I began looking at folate versus folic acid and found this article which involves B12. Perhaps it will add information to help you make decisions.



Thankyou very much Heloise, Looks very comprehensive! I'll delve into it later after work. :)



Wondering if you have read this article. Has he had his anti-bodies tested for PA ?

Also the B12 deficiency website has good information about other tests that could be done. Also the PAS forum where lots of us go for advice....

Sorry I am not able to pass on good advice concerning the MCV etc.


Hi your son's blood tests look fine. How does he feel? Has the doctor prescribed folic acid for him?


Thanks everyone for the good advice. Yes, shaws, he is on folic acid, but we aim to change to methylfolate in case he isn't able to absorb folic acid. We could ask our GP for a PA test.


You may also like...