What is vitamin B12 deficiency?  Vitamin B12 deficiency is a
condition in which the body has inadequate stores of vitamin
B12. This vitamin is essential for many aspects of health,
including the production of red blood cells. Healthy numbers of
red blood cells are critical for delivering oxygen and nutrients
to the body’s cells and tissues.  Vitamin B12 is a water-soluble
vitamin that must be ingested daily and absorbed effectively by
the digestive tract in order to maintain optimal health. Most
people get enough vitamin B12 by eating a variety of foods.
Those that naturally contain vitamin B12 include lean red meats,
poultry, fish, brewer’s yeast, and dairy products, such as milk,
cheese, and yogurt. Vitamin B12 is also added to some breakfast
cereals, breads, and other fortified food products.  Vitamin B12
deficiency is most common in people who have a disease or
condition in which the body is unable to absorb vitamin B12 from
ingested foods. It is also relatively common in older adults.
One in 31 adults ag