Epub 2006 Apr 3.Butler CC1, Vidal-Alaball J, Cannings-John R, McCaddon A, Hood K, Papaioannou A, Mcdowell I, Goringe A.Author information1Department of General Practice, Cardiff University, Wales, UK.AbstractBACKGROUND: Vitamin B(12) deficiency is common, increasing with age. Most people are treated in primary care with intramuscular vitamin B(12). Several studies have reported equal efficacy of oral administration of vitamin B(12).OBJECTIVES: We set out to identify randomized controlled trial (RCT) evidence for the effectiveness of oral versus intramuscular vitamin B(12) to treat vitamin B(12) deficiency.METHODS: We conducted a systematic review searching databases for relevant RCTs. Outcomes included levels of serum vitamin B(12), total serum homocysteine and methylmalonic acid, haemoglobin and signs and symptoms of vitamin B(12) deficiency.RESULTS: Two RCTs comparing oral with intramuscular administration of vitamin B(12) met our inclusion criteria. The trials recruited a total of 108 participants and followed up 93 of these from 90 days to 4 months.
In one of the studies, mean serum vitamin B(12) levels were significantly higher in the oral (643 +/- 328 pg/ml; n = 18) compared with the intramuscular group (306 +/- 118 pg/ml; n = 15) at 2 months (P < 0.001) and 4 months (1005 +/- 595 versus 325 +/- 165 pg/ml; P < 0.0005) and both groups had neurological responses. In the other study, serum vitamin B(12) levels increased significantly in those receiving oral vitamin B(12) and intramuscular vitamin B(12) (P < 0.001).CONCLUSIONS: The evidence derived from these limited studies suggests that 2000 microg doses of oral vitamin B(12) daily and 1000 microg doses initially daily and thereafter weekly and then monthly may be as effective as intramuscular administration in obtaining short-term haematological and neurological responses in vitamin B(12)-deficient patients.PMID: 16585128 DOI: 10.1093/fampra/cml008 [Indexed for MEDLINE] Publication typesComparative StudyResearch Support, Non-U.S. Gov'tReviewMeSH termsAdministration, OralAnemia, Pernicious/drug therapyHumansInjections, IntramuscularRandomized Controlled Trials as TopicVitamin B 12/administration & dosage*Vitamin B 12 Deficiency/drug therapy*Vitamin B Complex/administration & dosage*SubstancesVitamin B ComplexVitamin B 12Full Text SourcesSilverchair Information SystemsOvid Technologies, Inc.Other Literature SourcesCOS Scholar UniverseCited by Patents in - The LensMedicalB Vitamins - MedlinePlus Health InformationMiscellaneousCYANOCOBALAMIN - Hazardous Substances Data BankNCI CPTC Antibody Characterization Program
Vitamin B12 deficiency is common and rises with age. Most people with vitamin B12 deficiency are treated in primary care with intramuscular vitamin B12 which is a considerable source of work for health care professionals. Several case control and case series studies have reported equal efficacy of oral administration of vitamin B12 but it is rarely prescribed in this form, other than in Sweden and Canada. Doctors may not be prescribing oral formulations because they are unaware of this option or have concerns regarding effectiveness.To assess the effectiveness of oral vitamin B12 versus intramuscular vitamin B12 for vitamin B12 deficiency.Searches were undertaken of The Cochrane Library, MEDLINE, EMBASE and Lilacs in early 2005. The bibliographies of all relevant papers identified using this strategy were searched. In addition we contacted authors of relevant identified studies and Vitamin B12 research and pharmaceutical companies to enquire about other published or unpublished studies and ongoing trials.
Randomised controlled trials (RCTs) examining the use of oral or intramuscular vitamin B12 to treat vitamin B12 deficiency.All abstracts or titles identified by the electronic searches were independently scrutinised by two reviewers. When a difference between reviewers arose, we obtained and reviewed a hard copy of the papers and made decisions by consensus. We obtained a copy of all pre-selected papers and two researchers independently extracted the data from these studies using piloted data extraction forms. The whole group checked whether inclusion and exclusion criteria were met, and disagreement was decided by consensus. The methodological quality of the included studies was independently assessed by two researchers and disagreements were brought back to the whole group and resolved by consensus.Two RCT's comparing oral with intramuscular administration of vitamin B12 met our inclusion criteria. The trials recruited a total of 108 participants and followed up 93 of these from 90 days to four months.
High oral doses of B12 (1000 mcg and 2000 mcg) were as effective as intramuscular administration in achieving haematological and neurological responses.The evidence derived from these limited studies suggests that 2000 mcg doses of oral vitamin B12 daily and 1000 mcg doses initially daily and thereafter weekly and then monthly may be as effective as intramuscular administration in obtaining short term haematological and neurological responses in vitamin B12 deficient patients.The requested URL /index.php?option=com_content&view=article&id=3&Itemid=13 was not found on this server.Your doctor may prescribe vitamin B12 injections if you have low levels of B12 in your blood, a condition known as vitamin B12 deficiency. B12 deficiency can result if you don't eat enough of certain foods, particularly meat, poultry and seafood, or if you have an inability to absorb vitamin B12 from food. If your B12 absorption is impaired, you will need to receive injections more frequently than you will if your deficiency is a result of an inadequate diet.
According to the Office of Dietary Supplements vitamin B12 is vital to the reaction that creates new DNA in your body. This function is particularly important in keeping your red blood cells healthy. With inadequate vitamin B12, your red blood cells can form incorrectly, leading to a condition known as megaloblastic anemia in which your red blood cells are swollen and ineffective. In addition to its role in DNA synthesis, vitamin B12 is necessary for the proper function of your nervous system. The daily recommended intake of vitamin B12 for adults is 2.4 mcg, and you can meet this need through supplementation or by eating a variety of animal products, including milk, meat and seafood. Vitamin B12 deficiency occurs in 1.5 to 15 percent of the general public. According to a 2008 article in the journal "Blood," it may take 2 to 5 years for clinical symptoms of vitamin B12 deficiency to appear in people with malabsorption disorders such as pernicious anemia or sprue. If you don't eat meat, as in the case of a vegan diet, it may take more than 10 years before signs of deficiency appear.
Deficiency is slow to develop because your body is able to store a large amount of vitamin B12 in the liver and other tissues. Symptoms of vitamin B12 deficiency include shakiness, inability to control bodily actions and neurological changes including psychosis or changes in mood. Doctors typically administer injections of vitamin B12 in doses of 1000 mcg. This amount of vitamin B12 corrects the physiological consequences of deficiency and also helps build up body stores of the vitamin. Of this 1000 mcg dose, your body retains approximately 150 mcg or roughly 15 percent. You retain a higher percentage of smaller doses, but the overall amount of vitamin B12 obtained from smaller doses is still less than that stored from a 1000-mcg injection. Owing to your body's ability to store large amounts of vitamin B12, injections may be infrequent once your deficiency is resolved. If you cannot absorb vitamin B12 from food, Dr. Ralph Caramel, author of a 2008 article on vitamin B12 in the journal "Blood," suggests an initial injection cycle of 8 to 10 administrations over the first two to three months, then injections once a month thereafter.
If you have low vitamin B12 levels that are due to improper intake, you will need fewer injections, provided you begin to eat foods rich in vitamin B12 more often. Always consult with your doctor or pharmacist regarding how often you should be receiving vitamin B12 injections. According to the Office of Dietary Supplements, overdosing on vitamin B12 is difficult and no known adverse health effects are associated with high vitamin B12 intakes from either food or supplements. Vitamin B12 can interact with certain medications, however. Check with your doctor or pharmacist about possible interactions these injections may have with other medications you are taking. Though very rare, allergic reactions to vitamin B12 injections have occurred, and switching to an oral preparation of vitamin B12 may help prevent the reaction or reduce its severity. How Fast Will B-12 Work? Why Are the B12 Injections Not Working? Are There Advantages of Sublingual Vitamin B12? Does Sublingual B12 Really Work?