Thyroid UK
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Advice on blood test results please, especially re deficiency in B12 and folate

Hello all, I recently did a fingerprick blood test at home and got these results:

CRP 3.90 (normal range <5.0 mg/L)

Ferritin 94.4 (normal range 20 - 150 ug/L)

TSH 2.37 (normal range 0.27 - 4.20 mIU/L)

T4 Total 64.0 (normal 64.5 - 142.0 nmol/L)

Free T4 11.17 (normal 12 - 22 pmol/L)

Free T3 3.27 (normal 3.1 - 6.8 pmol/L)

Anti-Thyroidperoxidase abs 314.8 (normal <34 kIU/L)

Anti-Thyroglobulin Abs 204.1 (normal <115 kU/L)

Vitamin D (25 OH) 63 (Ranges: Deficient = <25 nmol/L; Insufficient = 25 - 50; Consider reducing dose = >175


B12 219 (Ranges: Deficient = <140 pmol/L; Insufficient = 140 - 250; Consider reducing dose = >725)

Serum Folate 4.54 (Normal 8.83 - 60.8 nmol/L)

I'd be really grateful for any advice. I did the test about 10 days after starting to take NDT so I'm not surprised that TSH, T4, Free T4 and Free T3 are not exactly optimal. I was taking 1 grain at the time and now I'm on 2, so hopefully these results will improve. (I did mean to take the test before switching but it proved impossible for various reasons.)

Vit D has improved since being tested in March 2016, when it was 24. But what did surprise me was B12 and Serum Folate being found to be low as these were OK a year ago. Could this result be caused by the sudden switch to NDT?

4 Replies

Hi - deficiencies are very unlikely to be caused by a switch of medication, much more likely to be the deficiencies typically caused by the food intolerances and leaky gut associated with hashimotos. The damage caused to the lining of the intestine - even if negative for coeliac - leads to the body being unable to absorb nutrients from food. The most common of these, in order, are gluten, dairy and soy. Gluten is also thought to trigger the immune system to attack the thyroid, hence the advice you were given previously about gluten free. Did you go gluten free?

Regardless, you really need to supplement the folate and b12 as they are both very low. You really should get treatment from GP for both, but if they won't treat b12 then you need to supplement with metylcobalamin sublingual lozenges (capsules are destroyed by stomach acid) 5000/day for several months to bring levels up. You also need to keep supplementing vit d as that is still too low. Are you also taking vit k2-mk7 and magnesium? Your ferritin is very close to optimal.

You are very under-medicated, but I am not sure if you tested too quickly after starting ndt, i think this might be the case. Probably best to raise dose again, slowly, until you start to feel better. Then hold for 6-8 weeks before testing again. I think that is the usual advice, but I am sure someone who knows more about ndt will be along soon.

Gillian xx


Thanks for your reply. I am going to see my GP very soon and see if they will treat the folate and b12 deficiencies. I haven't gone gluten free yet as I want to ask my GP whether they think they should do a further test for coeliac disease. But I am planning to.


Please take a look at the PASoc forum in relation to B12 and folate deficiencies.

If your diet hasn't changed then that suggest that you may have an absorption problem. Getting B12 deficiency recognised and treated correctly can be problematic.


Thanks, that looks really useful. My diet hasn't changed, so I also thought it must be absorption problem.

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