Vitamin B-9, also known as folate or folic acid, and vitamin B-12, also known as cobalamin, are nutrients required in the diet. Vitamins are typically needed by enzymes in order to function properly, and they must be ingested. Enzymes are like little machines that help the body to make changes to chemicals and transfer energy. Folate and B-12 are found in certain foods, have important functions in the body and have a role in preventing diseases.
Sources
Vitaimin B-12 is synthesized by bacteria. It comes from animal products or supplements. According to the National Institutes of Health, animal products such as meat, particularly liver, as well as fish and poultry contain vitamin B-12. For those who abstain from meat, dairy products typically contain B-12. Some foods are also supplemented with vitamin B-12, such as breakfast cereals. Supplements are also available.
Folate is typically found in green leafy vegetables such as turnip greens and spinach. Citrus fruits are another source, as are liver and legumes such as beans and peas. It is also available in supplement form.
Structures
Vitamin B-12 contains a ringed molecule called corrin and the mineral cobalt, making the vitamin a red color. The corrin ring provides binding sites for enzymes.
Folate is involved in a cycle that converts it into several different forms. These are folic acid, tetrahydrofolic acid and ethylenetetrahydrafolic acid, according to "Lippincott's Illustrated Reviews: Biochemistry."
Functions
Vitamin B-12 transfers methyl groups, which act as isomerases. An isomerase transfers nearby chemical groups on a molecule. In the body, vitamin B-12 is bound to enzymes that metabolize fat and protein and helps regenerate folate.
Folate is needed in order to regulate nucleic acids, DNA and RNA, which are used to make the body's proteins. It is required for DNA synthesis and therefore cell division.
Associated Diseases
Low levels of vitamin B-12 have a damaging effect on the body. The nerves are particularly vulnerable, according to "Harrison's Principles of Internal Medicine." Deficiency can cause psychological problems such as fatigue, irritability and depression. Damage to the nerves in the body can lead to impaired sensation of touch as well as tingling sensations. Pernicious anemia occurs when the digestive tract cannot absorb B-12. It causes the nerve problems listed and leads to anemia, or low red blood cell numbers.
Low folate levels in pregnant women can cause spinal cord problems in the baby. It can also lead to cardiovascular disease, which includes complications of strokes and heart attacks. Other diseases, such cancer, may have a relationship to folic acid, but the relationships are not as well-established.
Toxicity
Vitamin B-12 has a low potential for toxicity. Folate is also has a low potential for toxicity, but excessive folic acid can trigger B-12 deficiency.
References
- National Institutes of Health: Dietary Supplement Fact Sheet: Vitamin B12
- National Institutes of Health: Dietary Supplement Fact Sheet: Folate
- "Lippincott's Illustrated Reviews: Biochemistry"; Richard A. Harvey, Ph.D., and Denise R. Ferrier; 2010
- "Harrison's Principles of Internal Medicine"; Anthony S. Fauci; 2008
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