Vitamin B-12 is a nutrient you generally receive from your diet. Your body needs it to function properly. Protein rich foods, like meat, poultry, shellfish, eggs and dairy, are primary sources. If your lab test indicates low B-12 blood levels, it means you are not getting enough B-12. According to the U.S Centers for Disease Control and Prevention, 1 in 31 adults over age 50 have low B-12.
Prevalence
Though low B-12 is commonly associated with adults over age 50, growing evidence indicates that the shortfall is more prevalent than previously thought. A review published in the June 2004 journal "Nutrition Reviews" analyzed data on plasma B-12 levels in the U.S and found that at least 40 percent of individuals had deficient or marginal B-12 plasma levels in nearly all locations and across age groups.
Implications
Vitamin B-12 is needed for healthy red blood cell formation. Red blood cells carry oxygen and nutrients throughout your body. B-12 is also necessary for the formation of DNA and RNA genetic material. B-12 helps promote proper central nervous system function and wound healing and repairs tissues. Another important role of B-12 is in the regulation of homocysteine, elevated levels of which are associated with an increased risk for heart disease, dementia and Alzheimer's disease.
Homocysteine
Homocysteine is a normally harmless amino acid. It is regulated primarily by the active forms of vitamins B-6, B-12 and folate, another B vitamin. Your body uses these B vitamins to regulate homocysteine by converting it to other substances, like cysteine, an amino acid that protects cells by acting as an antioxidant. When you have low B-12 levels, homocysteine levels increase.
Neurological Risk
The medical community is gaining a clearer understanding in the role of low B-12 and the risk for neurological disorders through research studies. A study published in the February 2002 "New England Journal of Medicine" found that elevated homocysteine levels are a strong independent risk factor for dementia and Alzheimer's Disease, finding that a homocysteine level greater than 14 ul/l nearly double the risk of Alzheimer's disease
Cardiovascular Risk
Heart disease is the primary cause of death in the U.S. Without enough B-12 to regulate homocysteine, the elevated levels can increase your risk of heart disease. According to a Feb. 15, 2000, article in the journal "American Family Physician", studies indicate that elevated homocysteine levels are associated with an increased risk of fatal and nonfatal cardiovascular disease, independent of classic cardiovascular risk factors.
Causes
Low B-12 has several causative factors including dietary deficiency, physiological absorption ability, and genetic predispositions. Pernicious anemia, an autoimmune disorder where your immune system attacks intrinsic factor, an enzyme needed to absorb B-12, can cause deficiency. Chronic alcohol consumption, stomach surgery and conditions like Crohn's disease can also cause malabsorption. Dietary deficiency is the primary cause of low B-12 levels.
Treatment
Treatment for low B-12 is aimed at the underlying cause. If you are not getting enough from your diet, a dietary change or supplementation can help. If you have an absorption problem, such as in pernicious anemia or following stomach surgery, you may require monthly intramuscular injections. If your B-12 lab test is low, consult your doctor for the most effective strategy for your individual situation.
References
- Centers for Disease Control and Prevention: Learn More About Vitamin B-12 Deficiency
- "Nutrition Review"; Folate and Vitamin B-12 Status in the Americas; Lindsay H. Allen, Ph.d.; June 2004
- Linus Pauling Institute at Oregon State University; the Vascular Toxicity of Homocysteine and How to Control It; Mark F. McCarty et al.; November 1999
- "The New England Journal of Medicine"; Plasma Homocysteine as Risk Factor for Dementia and Alzheimer's Disease; Sudha Seshadri, et al.; February 2002
- "American Family Physician"; Homocysteine Levels and Cardiovascular Disease; Richard Sadovsky; Feb. 15, 2000
- Familydoctor.org: Vitamin B-12
Member Comments