Vitamin B12


  • Vitamin B12 works with folate, another B vitamin, to make the DNA in cells.
  • It helps nerve cells communicate with each other.
  • It is necessary for energy production in the cells.


  • It’s found in animal products such as beef, pork, chicken, fish, milk, and some cheese.
  • Plant-based foods do not contain Vitamin B12, unless it has been added during food processing (e.g., fortified cereal).


  • The body produces a protein in the stomach called intrinsic factor, which is necessary to absorb Vitamin B12. Aging decreases the amount of intrinsic factor, leading to Vitamin B12 deficiency.
  • Vegetarians who do not supplement with Vitamin B12 are at risk of deficiency.
  • Signs of Vitamin B12 deficiency:
    • Pernicious or megaloblastic anemia
    • Fatigue
    • Weakness
    • Weight loss
    • Depression
    • Confusion
    • Poor memory
    • Sore mouth or tongue


  • Vitamin B12 levels are determined by a blood test.
  • If the blood level is low, the provider will recommend a Vitamin B12 supplement of 1000mcg per day.
  • Older adults should use the sublingual form of Vitamin B12 that dissolves under the tongue. It is absorbed directly into the blood stream, bypassing the stomach and the lack of intrinsic factor.
  • Supplements can be purchased wherever vitamins and minerals are sold. Look for the USPS label to confirm it is a quality vitamin.