If you are over fifty, get most of your vitamin B12 from a supplement or fortified food, not just from meat, fish and dairy. That is the standing advice from the US National Institutes of Health, and the reason is absorption.
To release the B12 bound up in food, your stomach needs acid. Many older adults make too little of it, and an estimated 10 to 30 percent of older people may not absorb food B12 well.
B12 in supplements and fortified foods is already in free form, so it skips that acid step. At normal doses it still needs a stomach protein called intrinsic factor to be absorbed.
The daily target for adults is 2.4 micrograms. Multivitamins typically contain 5 to 25 micrograms, so a standard one usually covers it.
Some medicines make this more pressing. Metformin, used for type 2 diabetes, and long-term stomach-acid reducers such as omeprazole can lower B12 levels over time.
Low B12 can cause tiredness, numbness or tingling in the hands and feet, balance problems and memory trouble. The NIH notes that nerve damage can happen even without anemia.
Those symptoms are easy to blame on age. A blood test can check, though a borderline result may need a second test.
Here is the move. Check your multivitamin or fortified cereal and make sure your daily total reaches 2.4 micrograms, which equals 100 percent of the Daily Value on the label.
If you take metformin or an acid reducer long term, eat little or no animal food, or have had stomach or intestinal surgery, ask your doctor: “Can we check my B12 level, and methylmalonic acid if it comes back borderline?”
The same goes for anyone with pernicious anemia, atrophic gastritis, celiac disease or Crohn’s disease. For them, a multivitamin may not be enough.
On the label, the form matters less than you might think. Cyanocobalamin is the most common form, and the NIH says no form has been shown to be better than the others.
The NIH says B12 has not been shown to cause harm even at high doses, but no upper limit has been set and some observational studies have raised questions about very high intakes. A confirmed deficiency is usually treated with injections under a clinician’s care, though very high oral doses can also work.
Two point four micrograms, from a source your body absorbs easily. Check one label today.
