I had a nasty surprise last week when my doctor called to let me know that my bloodwork showed I had a very low B12 level and needed to take megasupplements, and possibly shots if those don't work.
Of course, I headed straight for Dr. Google, and learned some interesting things.
B12 is found in red meats (liver mostly, gag), oily fish (mackerel, salmon), shellfish, dairy and -- really truly -- raw egg yolks.
Symptoms include: extreme fatigue, burning/tingling in hands and feet, joint pain, memory loss, intestinal difficulties. (I haven't had all those symptoms, but I've been exhausted for over a year.)
Why a low level? It might be (some say it probably is) caused by a lack of ability for the intestines to absorb B12 in food, which may be caused by Celiac disease.
Another interesting fact: different countries have different definitions of "low level." (I don't yet know what mine is. She's mailing me the blood test results but wanted to warn me.) Japan has the highest -- 500 -- AND a much lower level of Alzheimer's than other countries. (I read so many different base levels in the U.S. I gave up.)
I thought this might be of interest to people. I'd certainly never worried about it before. Like many things, B12 levels decrease (sigh) with age.