where is vitamin b12 absorbed
Be aware that certain brands, but not all, contain B12. Oral or parenteral therapy for B12 deficiency. After this, vitamin B12 combines with a protein made by the stomach called intrinsic factor and is absorbed by the body.
High homocysteine levels are linked with a higher incidence of Alzheimer’s disease, dementia, and cognitive decline. In addition, folic acid deficiency can cause falsely low serum vitamin B12 levels. J Am Geriatr Soc. Malouf R, Evans JG. JAMA. Taking the widespread use of these agents and the aging of the U.S. population into consideration, the actual prevalence of vitamin B12 deficiency may be even higher than statistics indicate. [1]. For example, just 10μg out of a 500μg dose of vitamin B12. This possibility becomes especially important when considering vitamin replacement therapy. The incidence, however, appears to increase with age. A prescription form of vitamin B12 can be given by injection or as a nasal gel. The authors thank Linda L. Brown, M.D., Department of Internal Medicine, Walter Reed Army Medical Center, Washington, D.C., for review of the manuscript. Vitamin B12 is utilized in many parts of the body and metabolism. In one study,18 38 patients with vitamin B12 deficiency were randomized to receive oral or parenteral therapy. It is ⦠Arch Intern Med 1999;159:1297. Medicine's best kept secret?. Kelly JP, It is also a key player in the function and development of brain and nerve cells. Sources of funding: none reported. Vitamin B12 binds to the protein in the foods we eat. Diagnosis of vitamin B12 deficiency is typically based on measurement of serum vitamin B12 levels; however, about 50 percent of patients with subclinical disease have normal B12 levels. Neuropsychiatric disorders caused by cobalamin deficiency in the absence of anemia or macrocytosis. Grigsby J, The nearly ubiquitous use of gastric acid–blocking agents, which can lead to decreased vitamin B12 levels,2 may have an underappreciated role in the development of vitamin B12 deficiency. The dietary limitations of strict vegans make them another, less common at-risk population. afpserv@aafp.org for copyright questions and/or permission requests. Suggested approach to the patient with suspected vitamin B12 deficiency. Plasma homocysteine levels and mortality in patients with coronary artery disease. Because most clinicians are generally unaware that oral vitamin B12 therapy is effective,17 the traditional treatment for B12 deficiency has been intramuscular injections. You should seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. / afp
Abrahm JL, It's readily available in animal products, including fish, meat, poultry, eggs, and milk and other dairy foods. Yu F, Bradford GS, A Cochrane review on folic acid supplements and cognition, with or without vitamin B12, did not find a significant effect of the supplements vs. placebo on cognitive function in healthy elderly people or people with dementia. Vitamin B12 tablets are available in high dosages far above the recommended dietary allowance, but these high amounts are not necessarily the amount that will be absorbed because an adequate amount of intrinsic factor is also needed. Relative sensitivities of serum cobalamin, methylmalonic acid, and total homocysteine concentrations. Contrary to prevailing medical practice, studies show that supplementation with oral vitamin B12 is a safe and effective treatment for the B12 deficiency state.