Daughter has been on b12 jabs for over 3 years; still unwell with neuro symptoms, and b12 level of 2000. So, going to doctor to ask for more tests to determine why level is so high when she's obviously showing many symptoms of deficiency, (3 of my daughters are b12 deficient). Know about functional deficiency etc, but could someone tell me what other test are worth asking that won't be a waste of time as she is on the jabs 7 weekly. I've read about many tests - MMA, Homocysteine, Active b12, TC11, Thyroid, Folate, Ferritin, Vit D, etc, but which ones will be ok with this supplementing, and are there any more, and which 'forms' of the tests should they be? Thank you.