Vitamin B12 (cobalamin) is an essential water-soluble vitamin that the body uses to maintain healthy nerve cells, produce RNA, DNA and red blood cells and help iron to function properly. B12 also works with folate to produce the amino acid SAMe which controls mood and supports immune function. B12 injections have many benefits and are often prescribed for deficiencies that cause fatigue, shortness of breath, diarrhea, numbness and neurological damage.
Absorption and Availability
A B12 deficiency can result from a lack of intrinsic factor, a substance needed to absorb B12. One of the benefits of B12 injections over oral supplements is its immediate availability to the body. Injections that go directly into the blood stream bypass absorption barriers according to the National Institutes of Health (NIH) and can help people with malabsorption issues like those who have intestinal disorders or have undergone intestinal surgeries.
Pernicious and Megaloblastic Anemia
Pernicious and megaloblastic anemia can occur due to a lack of intrinsic factor and malaborption of B12. Symptoms of anemia include weakness, paleness, diarrhea, weight loss, fever, numbness in the extremities, difficulty balancing, confusion, memory loss and moodiness. According to the NIH and Mayo Clinic, pernicious anemia is a lifelong condition that occurs in 1 to 2 percent of older adults and is treated with high dose B12 injections.
Fatigue and Chronic Fatigue Syndrome
The University of Maryland Medical Center (UMMC) says fatigue caused by a B12 deficiency is often alleviated with B12 injections which boosts energy. Chronic fatigue syndrome (CFS) is a condition characterized by extreme tiredness that gets in the way of normal everyday activities. Regular B12 injections over several weeks may improve CFS symptoms but further testing is needed to confirm its efficacy.
Vitamin B12 supplementation is being studied for its effects on a variety of conditions. According to the Mayo Clinic, current research surrounding B12 is looking at its effects on Alzheimer's and dementia, breast cancer, heart disease and high cholesterol. Other conditions that have been studied but need more research to confirm the benefits of B12 include male infertility, asthma, Parkinson's disease and sickle cell disease.