Vitamin B-12 helps your body produce red blood cells, and aids in transporting oxygen to energize your body. Thus, this vitamin does not make you tired. On the contrary, vitamin B-12 can help fight fatigue, because it prevents the fatigue-inducing anemia associated with a B-12 deficiency. Since tiredness occurs as a sign of other health problems, do not assume you need more vitamin B-12 if your energy is low. Consult your doctor before supplementing your diet with it.
When you are low on vitamin B-12, you may develop a type of anemia known as megaloblastic anemia. Fatigue, constipation, decreased appetite, numbness and tingling are symptoms of a nutrient deficiency. Children who do not ingest an adequate supply of B-12 develop motor and cognitive impairments.
B-12 Deficiency Causes
A vitamin B-12 deficiency can develop for several reasons. Pernicious anemia, for example, harms the stomach cells necessary for producing gastric acid. Ths acid is needed to extract vitamin B-12 from the foods you eat. Thus, if you suffer from pernicious anemia, your body cannot absorb vitamin B-12. Another condition, atrophic gastritis, which is often caused by a bacterial infection, inflames the stomach, which also impairs your ability to absorb B-12.
Recommended Daily Intake
You can avoid feeling tired from low levels of vitamin B-12 by observing the recommendations of the Food and Nutrition Board of the Institute of Medicine. From 14 years through adulthood, men and women require 2.4 micrograms of B-12 daily. Pregnant women require more B-12 -- 2.6 micrograms per day.
B-12 Deficiency Treatment
After your doctor confirms through lab tests that your body is deficient in vitamin B12, follow her instructions for correcting the condition. The type of treatment you receive depends on what caused the deficiency. You may need to receive B12 injections if you have a medical condition preventing your body from absorbing the nutrient from foods, says the Office of Dietary Supplements. However, if you can absorb B-12 properly, you can take vitamin tablets.