Vitamin B12 is essential for proper red blood cell formation and proper transmission of nerve signals and nerve health. Because vitamin B12 is important for red blood cells, a deficiency in the vitamin leads to a condition called anemia, which is characterized by a lack of healthy red blood cells. According to the Linus Pauling Institute, vitamin B12 deficiency affects approximately 10 to 15 percent of adults older than the age of 60 years.
Physiology
The absorption of vitamin B12 is a complicated process that involves several different mechanisms. When you eat foods that contain vitamin B12, the hydrochloric acid in your stomach helps break down the food to isolate the vitamin. After vitamin B12 is isolated, a protein called intrinsic factor, which is produced by the parietal cells in the stomach, binds to the vitamin and carries it to the small intestine, where it is able to enter the bloodstream. If any of these processes is disrupted, it can lead to a type of vitamin B12 deficiency called pernicious anemia.
Causes
The body's ability to produce intrinsic factor naturally declines with age. Because of this, it is more difficult for elderly adults to absorb vitamin B12 from the foods they eat. The Linus Pauling Institute notes that approximately 2 percent of adults older than age 60 years have pernicious anemia because of vitamin B12 deficiency.
A condition called atrophic gastritis, which is characterized by inflammation of the stomach lining, affects 10 to 30 percent of adults older than the age of 60 years. This condition affects the absorption of vitamin B12 and increases the risk of developing anemia from vitamin B12 deficiency. Some older adults may also develop a vitamin B12 deficiency because of stomach or intestinal surgery.
Symptoms
Because anemia is characterized by a lack of healthy red blood cells, the initial symptoms of the condition usually include fatigue, shortness of breath and pale skin and gums. As the deficiency progresses, it can cause damage to the nerves, which manifests as numbness and tingling in the extremities, difficulty walking, confusion and muscle pain. Often, the nerve damage that develops from a vitamin B12 deficiency is irreversible.
Vitamin Needs
All adults older than 51 years of age require 2.4 mcg of vitamin B12 per day. Synthetic versions of vitamin B12 are more easily absorbed by elderly adults, so the Linus Pauling Institute notes that older adults should meet their vitamin B12 needs through fortified foods or supplements. Fortified breakfast cereals and fortified soy milk contain synthetic versions of vitamin B12. In addition to supplements, some lozenges also contain synthetic vitamin B12.
