Depression, nervousness, memory loss, Alzheimer like symptoms ( looks like Alzheimer but is not ), numbness of the feet, back pain, red and sore tongue, and heart palpitations. Interesting isn't it. Realize as you read these symptoms there are "degrees" of affliction. Now before you go away, I will list the medications in which you are LIKELY to be deficient.
You take the following medications, birth control pills, a cholesterol lowering drug (statins), metaformin for type 2 diabetes, protein pump medications to control acid reflux, antacids, potassium supplements, dilantin for seizures and nicotine if you smoke.
And now the conditions that may cause a decrease in absorption of B 12. Alcoholism or a drink or two every day, old age, and vegetarianism. Older or elderly people have less acid in their stomach's as the get older! Anything that reduces acid in the stomach interferes and decreases absorption!
There is some controversy about how B 12 should be taken. Some say it should be taken orally or sub lingual ( under the tongue). Some say you should get it as a shot at your doctor, but I am confident that taking it sub lingual will work. Heck if it does not get absorbed sub lingual, you will swallow it eventually anyway! A win win situation. The argument is that not much is absorbed by this route and that is true a great deal of the time. This is why my readings suggest that LARGE doses should be taken to compensate for this lack of efficiency. As little as one percent of the B 12 taken sub lingual/ oral maybe absorbed!
To my knowledge there never has been a over dosage of vitamin B 12 that caused any symptoms. I have even seen articles that tell of people with a yeast infection of the gut and resultant HUGE doses of B 12 and no side effects. These levels are levels that will not occur with any practical usage of the B 12 dosages I am going to suggest. So I do not see a down side to taking B 12 and a lot of upside. ( If there is B 12 in your Multivitamin there is not much and that goes for B complex vitamins also). Who wants to be diagnosed with Alzheimer's disease, and after your demise, for your family to find out it was just a B 12 deficiency. Not me!
So here is what I see recommended. A couple milligrams a day for a month then maybe a milligram everyday thereafter. Now you can go and get a blood level done by your doctor and he may tell you it is normal. My readings suggest that B 12 levels in the elderly should be HIGH normal or you can have signs you are deficient.. I have pointed you in the right direction and now it is up to you to follow up with your own readings. It is your health after all. It is all out there on the internet and you should not take for granted that you Health Provider is informed on this subject. Their sphere of expertise tends to be treatment and not prevention and is very frequently deficient in subjects related to what I blog about.
May the new year be better and better for you in every way......