Vitamin B-12 is one of eight water-soluble B vitamins essential to good health. It's primarily found in fish, meat, poultry, eggs, dairy products and other animal-based foods. If you don't get enough vitamin B-12 in your diet, your body can't make healthy red blood cells or efficiently synthesize DNA, which can lead to a myriad of health disorders.
Red Blood Cell Formation
The red blood cells in your body pick up oxygen from the lungs and transport it to all parts of your body. Red blood cells have a lifespan of approximately four months, which means your body is constantly making new ones. New red blood cells originate in your bone marrow, and vitamin B-12 is an integral part of this formation process. A vitamin B-12 deficiency can decrease your red blood cell count and cause anemia, a condition that makes you feel weak and tired.
The two forms of vitamin B-12 that your body uses are called methylcobalamin and 5-deoxyadenosyl cobalamin, according to the Linus Pauling Institute at Oregon State University. The methylcobalamin form of vitamin B-12 is important to your health because it's used by one of the enzymes that synthesizes DNA. Without it, your body can't make new cells.
Optic Nerve Health
In a 2005 article published by the European Journal of Internal Medicine, Dr. Michael S. Lee and his colleagues at the Cleveland Clinic Foundation presented evidence that vitamin B-12 is required for optic nerve function. Lee was able to trace the cause of a patient's impaired vision to optic nerve damage caused by a deficiency of vitamin B-12. After several months of treatment with vitamin B-12 injections, the patient's vision problem was corrected.
Effect on Depression
In late 2003, BMC Psychiatry published an article in which Dr. Jukka Hintikka and his team at Kuopio University Hospital in Finland present a 6-month clinical study of patients diagnosed with major depressive disorders. The patients were treated during the study with antidepressant medication or psychotherapy sessions. Hintikka concluded that, irrespective of the method of treatment, patients with higher blood levels of vitamin B-12 have more favorable treatment outcomes relative to those with lower levels of vitamin B-12. The research team speculates that patients with lower levels of vitamin B-12 may have higher blood levels of homocysteine, an amino acid that's thought to enhance symptoms of depression.
- NetDoctor: Anemia Due to Vitamin B12 Deficiency (Pernicious Anemia)
- Linus Pauling Institute at Oregon State University: Vitamin B12
- European Journal of Internal Medicine; Optic Neuropathy in Vitamin B12 Deficiency; Michael S. Lee et al.; October 2005
- BMC Psychiatry; High Vitamin B12 Level and Good Treatment Outcome May be Associated in Major Depressive Disorder; Jukka Hinikka et al.; December 2003
- Stockbyte/Stockbyte/Getty Images
This article reflects the views of the writer and does not necessarily reflect the views of Jillian Michaels or JillianMichaels.com.