Hi Magnus~

This is a low B12 level. While it may not fall outside of low end range, you will find plenty of data to suggest it is too low, and might very well be reason for some of your symptoms. Reference ranges vary by lab, but 306 is on the low side of typical ranges. Two follow up tests would be methylmalonic acid and homocysteine, and an elevation in either of those would clinch a B12 deficiency diagnosis. Anything under 400 is considered questionable, so I would not hesitate to take supplemental B12 (1000mcg daily preferably the methylcobalamin form) aiming for a B12 level near or over the top of range. And keep taking it to keep the level in upper range.

I personally had several years of neurologic and other symptoms before my low B12 level of 296 was finally discovered. My symptoms resolved with correcting the deficiency.

Here is some more info... with references about testing, dosages, etc. The AAFP and eMedicine articles are both very good. Vitamin B12 Deficiency

I am not as familiar with folate ranges, and I'm not sure where you fall without seeing the reference range.

I hope you will read about Celiac Disease. It is just one of many possible underlying causes of B12 deficiency, but the unexplained weight leaps out here. It is one of the more typical symptoms of CD. Celiac Disease is an autoimmune disease caused by an abnormal immune response to dietary gluten (wheat, barley, rye) that can result in a myriad of symptoms. More on that in The Gluten File linked in my signature.

Detecting Celiac Disease in Your Patients by Harold T. Pruessner, MD

Gluten-Sensitive Enteropathy (Celiac Disease): More Common Than You Think by David A. Nelson, JR, MD, MS (AAFP)

Gluten sensitivity as a neurological illness, M Hadjivassiliou, et al.


I can't comment on your other tests, but here is one of my favorite links that might help:
http://www.labtestsonline.org/

Hope this helps.

Cara