Vitamin B-12, also known as cobalamin, and folate or folic acid are important vitamins. B-12 vitamins help enzymes in the body to function. An enzyme is type of protein, which is a large chemical structure made of smaller chemicals called amino acids. Enzymes speed up and encourage chemical reactions, and are analogous to little machines. These vitamins are essential to proper functioning of many enzymes. Together, B-12 and folate are necessary for proper DNA replication, appropriate functioning of cells and good health.
Sources in the Diet
Bacteria synthesizes vitamin B-12 from the digestive tract or from the ingestion of animal products. Foods that supply vitamin B-12 include meats, particularly liver, fish, chicken and dairy products such as milk. As such, vegetarians who consume dairy may get an adequate amount of B-12, but vegans will need supplementation.
In contrast, folic acid is found in leafy vegetables such as spinach. Legumes are another source of this vitamin, as well as fortified grains, yeast, liver, many fruits and beer.
Supplements
Both vitamin B-12 and folate are available as supplements. Cobalamin is available as a pill and is added to many processed foods such as breakfast cereals. Folate has been added to flour, cold cereals, pasta, breads, cookies, crackers and bakery items since 1988 according to the National Institutes of Health. It is also available in pill form.
Populations Requiring Extra B12 and Folate
Certain people are at greater risk of B-12 and folate deficiency in the diet. Alcoholics often get inadequate nutritional intake, particularly vitamin B-12 and folate. The elderly may also be at risk. Pregnant women should receive folate supplements to help prevent certain birth defects such as spina bifida, in which the spinal column does not properly form. Some seizure medications, kidney dialysis and liver disease may decrease levels of folate, and those with problems absorbing nutrients, called malabsorption syndromes, are also at risk.
Inadequate Levels of B12 and Folate
Inadequate levels of vitamins B-12 and folate lead to a condition called macrocytic anemia. Since these vitamins are required for normal DNA function, insufficient amounts cause dysfunction of the DNA in bone marrow cells. These cells make red blood cells. Anemia is a condition of low red blood cell counts. These are the cells that take oxygen from the blood and deliver it to the tissues. Macrocytic is a term describing how the cells look under the microscope; macrocytic anemia is the condition of large cells that are few in number. Symptoms include fatigue, lightheadedness, lightening of the skin color and shortness of breath. Vitamin B-12 deficiency causes nerve damage, both to the nerves of the body and brain, in addition to microcytic anemia.
Excessive B12 and Folate
Excessive amounts of folate actually cause a vitamin B-12 deficiency. B-12 regenerates folate, when there is excessive folate ingested, vitamin B-12 is used up.
Vitamin B-12 and folate should not be taken in doses above the recommended allowance unless advised by a health care professional.
References
- "Lehninger Principles of Biochemistry"; David L. Nelson and Michael M. Cox; 4th Ed 2004
- "Nutrition: Concepts and Controversies"; Frances Sizer and Ellie Whitney; 11th Ed 2007
- MedlinePlus: Folic Acid
- "Harrison's Principles of Internal Medicine"; Anthony S. Fauci; 17th Ed 2008
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