The B groups of vitamins are as follows
Thiamin (B1);Riboflavin (B2);
Niacin (B3); Pantothenic acid (B5); Pyridoxine (B6);
Biotin (B7);Folate or 'folic acid' when included in supplements (B9);
Cyanocobalamin (B12).
Vitamin B12, also known as cobalamin, is a water-soluble vitamin involved in metabolism.
Chemical and physical properties of Vitamin B12:
Vitamin B12 has the largest and most complex chemical structure of all the vitamins. It is unique among vitamins in that it contains a metal ion, cobalt.
Vitamin B12 is a unique water-soluble vitamin that requires a specific protein called intrinsic factor for absorption in the body.
The chemical name of vitamin B12 is that it's cyanocobalamine and it contains cobalt.
Vitamin B12 is a water-soluble vitamin that is naturally present in some foods, added to others, and available as a dietary supplement and a prescription medication.
Because vitamin B12 contains the mineral cobalt, compounds with vitamin B12 activity are collectively called cobalamins.
Biochemical function of vitamin B12:
Vitamin B12 is an especially important vitamin for maintaining healthy nerve cells, and it helps in the production of DNA and RNA, the body's genetic material. Vitamin B12 works closely with vitamin B9, also called folate or folic acid, to help make red blood cells and to help iron work better in the body.
Vitamin B12 is found in a wide variety of animal foods. Plant foods have no or low vitamin B12 unless they are fortified. You can get recommended amounts of vitamin B12 by eating a variety of foods including the following: Fish, meat, poultry, Oysters ,eggs, milk, and other dairy products like cheese ,paneer, yogurt,dahi contain vitamin B12
The mechanism of action of vitamin B12::
Vitamin B12 facilitates several methylation reactions within the body. Methylcobalamin serves as a cofactor in the conversion of homocysteine to methionine in the body. Furthermore, in the form of adenosylcobalamin, the vitamin is crucial in converting methylmalonyl-coenzyme -A (CoA) to succinyl-CoA.
The antioxidant properties of vitamin B12:
The potential antioxidant properties of B12 include:
(1) Direct scavenging of reactive oxygen species (ROS), in particularly superoxide;
(2) Indirect stimulation of ROS scavenging by preservation of glutathione; (3) Modulation of cytokine and growth factor production to offer protection from immune response-induced .
The major functions of vitamin B12:
Vitamin B12 is crucial to various bodily processes, including :
•Normal functioning of the brain and nervous system.
•Cognitive functioning (ability to think)
•Formation of red blood cells and anemia prevention.
•Helping synthesize and regulate DNA.
•Helping protect the eyes from macular degeneration
•Necessary for energy production
•Vitamin B12 is essential for healthy blood. When the body does not have enough B12, it leads to decreased normal red blood cell production (anemia), which impairs oxygen delivery.
Megaloblastic anemia, also called nutritional-deficiency anemia, is a type of anemia caused by B12 or folate deficiency. Megaloblastic anemia is characterized by impaired DNA synthesis and the formation of large, abnormal, immature red blood cells(RBC)
Possibly preventing congenital abnormalities
General physical symptoms of vitamin B12 deficiency can include:
•Feeling very tired or weak.
•Experiencing nausea, vomiting or diarrhea.
•Not feeling as hungry as usual.
•Weight loss.
••Having a sore mouth or tongue.
•Having yellowish skin.
Left untreated, a vitamin B-12 deficiency can lead to symptoms such as anemia, fatigue, muscle weakness, numbness , trouble walking, nausea, weight loss, irritability, fatigue, and increased heart rate intestinal problems, nerve damage and mood disturbances
The recommended daily amount of vitamin B-12 for adults is 2.4 micrograms (mcg).,2.6 mcg for pregnant women qnd 2.8 mcg for old
Persons.
Vitamin B12 deficiency leads to a serum build-up of methylmalonic acid. Deficiency of vitamin B12 or folic acid can lead to increased homocysteine levels.
Lower the Vitamin B12 level higher the homocysteine.
High levels of homocysteine in your blood may be a sign that this process isn't working properly or that you're lacking certain B
vitamins. High levels of homocysteine can damage the inside of your arteries and increase your risk of forming blood clots
High homocysteine level increase the risk of cardiovascular disease , stroke, vascular dementia,
Parkinson's disease
associated dementia,
Osteoporosis; Atherosclerosis , thrombus, fatigue, pulmonary embolism. multiple sclerosis.
If you have high levels of homocysteine, your healthcare provider may recommend taking supplements of: Vitamin B6. Vitamin B12. Folic acid (the human-made form of folate)..
Most common causes of vitamin B12 deficiency:
(1) Medications:Certain medications can cause low levels of vitamin B12 in your body.
Vitamin B12 absorption and utilization by the body can be compromised with the chronic use of certain medications which include: colchicine, chloramphenicol, ethanol, Histamine 2 receptor antagonists (H2RA), metformin, and proton pump inhibitors (PPI)..Proton pump inhibitors (PPIs) are used to treat GERD and peptic ulcers), histamine H2 blockers (a medicine used to reduce the amount of acid your stomach makes)
(2) Long-term use of antibiotics such as Chloramphenicol can lower vitamin B levels in the body, particularly B2, B9, B12, and vitamin H (biotin), which is considered part of the B complex vitamins.
Chloramphenicol can cause bone marrow depression and inhibit red blood cell maturation, which may interfere with the therapeutic effects of iron or vitamin B12 in the treatment of anemia.
(3)Colchicine is used to prevent gout attacks (sudden, severe pain in one or more joints caused by abnormally high levels of a substance called uric acid in the blood) in adults. Colchicine (Colcrys) is also used to relieve the pain of gout attacks when they occur.
Vitamin B12 is a necessary cofactor for production of S-adenosyl methionine, a compound necessary for methylation of myelin sheath phospholipids and myelin formation. Colchicine impairs B12 absorption while N2O irreversibly inactivates systemic B12.
(4) The body's ability to absorb B12 from food can be reduced because alcohol can damage the lining of the stomach and intestines. The storage of B12 takes place through the liver, as alcohol can cause liver damage and inflammation reduces the ability to store and release B12 when needed
)5) Histamine is responsible for the wheal and flare reaction in various allergic conditions. Classical antihistamines are the drugs which block the H 1 receptors and are widely used in various allergic conditions, whereas H 2 blockers are mainly used for acid peptic disease.
The initial H2 blocker approved for use in the United States was Cimetidine (1977), which was followed by Ranitidine (1983), Famotidine (1986), and Nizatidine (1988).
(6) Proton pump inhibitors (PPIs) are a group of medicines that decrease stomach acid production. They can help relieve symptoms of chronic acid reflux (GERD) and stomach ulcers.
Esomeprazole 40 mg provides more effective intragastric acid control than Lansoprazole 30 mg, Omeprazole 20 mg, Pantoprazole 40 mg and Rabeprazole 20 mg in patients with gastro-oesophageal reflux symptoms
(7)Metformin a drug for sugar control in diabetics can commonly reduce vitamin B12 levels in patients, which may lead to vitamin B12 deficiency. the risk of low vitamin B12 levels increases with higher metformin dose, longer treatment duration, and in patients with risk factors for vitamin B12 deficiency.
(8) Pernicious anemia is an autoimmune disease in which your body can't make intrinsic factor, a protein needed to absorb B12. So even if you're eating a lot of meat or taking vitamin supplements, you're not absorbing B12. Pernicious anemia is the most common cause of B12 deficiency.
(9)Diet: Some people can develop a vitamin B12 deficiency as a result of not getting enough vitamin B12 from their diet. A diet that includes meat, fish and dairy products usually provides enough vitamin B12, but people who do not regularly eat these foods can become deficient.
(10) The World Health Organization (WHO) identifies pregnant and lactating women as among the groups at greatest risk of vitamin B12 deficiency
(11) Older adults: Between 3% and 43% of community-dwelling older adults, especially those with atrophic gastritis (an autoimmune condition) have vitamin B12 deficiency
Pernicious anemia is a relatively rare autoimmune disorder that causes diminishment in dietary vitamin B12 (cobalamin) absorption, resulting in B12 deficiency and subsequent megaloblastic anemia. It affects people of all ages worldwide, particularly those over 60.
Being older than 75 years: People over 75 are more at risk for developing vitamin B12 deficiency because their bodies are often unable to fully absorb vitamin B12
(12) A vegan diet includes only plant foods—fruits, vegetables, beans, grains, in nuts, and seeds. People who follow a vegan diet don't eat any animal foods, including dairy, eggs, and honey. Vegans who consume no animal products and vegetarians who consume some animal products (e.g., dairy products, eggs, or both) but not meat have a higher risk of vitamin B12 deficiency
(13) Conditions that affect your small intestines like Crohn's disease, celiac disease, bacterial growth, or a parasite can lead to vitamin B12 deficiency.
Intestinal surgery can lead to vitamin B12 deficiency.
(14) Bacterial infection:
One organism that is associated with vitamin B12 deficiency is Helicobacter pylori, found in over half of all patients. Adequate treatment of this infection has been shown to result in an increase in the concentration of the vitamin.
Vitamin B12 deficiency leads to a serum build-up of methylmalonic acid. Deficiency of vitamin B12 or folic acid can lead to increased homocysteine levels.
Lower the Vitamin B12 level higher the homocysteine.
High levels of homocysteine in your blood may be a sign that this process isn't working properly or that you're lacking certain B
vitamins. High levels of homocysteine can damage the inside of your arteries and increase your risk of forming blood clots
High homocysteine level increase the risk of cardiovascular disease , stroke, vascular dementia,
Parkinson's disease
associated dementia,
Osteoporosis Atherosclerosis , thrombus, fatigue, pulmonary embolism. multiple sclerosis.
If you have high levels of homocysteine, your healthcare provider may recommend taking supplements of: Vitamin B6. Vitamin B12. Folic acid (the human-made form of folate).
*Blood test to estimate B12 levels:
Vitamin B levels may be checked in blood or urine. For a blood test, a health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial.
In patients with suspected B12 deficiency, initial lab tests should include a complete blood count (CBC) with a peripheral smear and serum B12 and folate levels.
An MMA test is most often used to diagnose a vitamin B12 deficiency.
• Normal level of vitamin B12 in your bloodstream is generally between 190 and 950 picograms per milliliter (pg/mL). Between 200 to 300 pg/mL is considered borderline and your doctor may do more testing. Values of less than 160 pg/ ml are a possible sign of a vitamin B12 deficiency.
A deficiency in either of these vitamins can cause a wide range of problems, including: extreme tiredness. a lack of energy. pins and needles.
Your provider may also recommend a vitamin B12 test if you have certain nervous system symptoms. A low level of B12 can cause numbness or tingling in the arms and legs, weakness, and loss of balance. Other conditions for which the test may be done include: Sudden severe confusion ( delirium ).
For vegetarians looking to increase their vitamin B12 intake, there are a variety of options. Some good choices for B-12 include:
yogurt,Dahi, low-fat milk,
fortified plant-based milk;
cheese;eggs (egg yolk);
fortified cereals;
nutritional yeast,. Certain mushrooms ;Blue green alage.
If you follow a plant-based diet, then vegetables like spinach, beetroot, butternut squash, mushroom and potato contain good amounts of vitamin B12. However, it is less likely to receive the whole amount of nutrients just from vegetable sources.
Fruits best for vitamin B12:
You can include apples, bananas, blueberries, oranges, and currants to get your dietary fix of vitamin B12. Each of such vitamin B12 fruit has numerous beneficial nutrients that contribute to eating a vitamin B12 nutrient-dense diet.
A versatile fruit, bananas offer a convenient source of vitamin B12, with approximately 0.1 micrograms per 100 grams, making them an easy addition to your diet
Mango's humble 'gutli' is rich in vitamin B12.
Dry fruits rich in Vitamin B12
Almonds. Eating almonds daily can help increase the Vitamin B12 content inside the body.
Dates. Dates are not just sweet in taste, but are also a rich source of Vitamin B12.
Walnuts; Sunflower seeds;.
Figs;Cashews;Pumpkin seeds
Vitamin B12 rich foods of animal origin;
(1) Meat: Pork, lamb, and other meats are excellent sources of vitamin B12.
(2) Poultry: Chicken and turkey are good sources.
(3) Fish: Fish, particularly oily fish like salmon, trout, tuna, and sardines, are rich in B12.
(4) Shellfish: Clams, mussels, crabs, and oysters contain significant amounts of vitamin B12.
The most common form of vitamin B12 in dietary supplements is cyanocobalamin. Other forms of vitamin B12 in supplements are adenosylcobalamin, methylcobalamin, and hydroxycobalamin . No evidence indicates that absorption rates of vitamin B12 in supplements vary by form of the vitamin.
Cyanocobalamin is a man-made form of vitamin B12 used to prevent and treat low blood levels of this vitamin. Most people get enough vitamin B12 from their diet.
Zincovit capsule contains essential vitamins like Vitamin A, B1, B2, B3, B5, B6, B12, C, D3, E and Folic acid are its core constituents.
Neurobion Forte Tablets is a combination of Vitamins B12, B1, B6, which helps provide relief from Tingling, Numbness & Weakness 30 Tablets. It is used as supplementation to support healthy nerves and help relieve symptoms like tingling and numbness in hands & feet (caused due to B-vitamin deficiency).
The composition of Becosules includes vitamin B-complex including thiamine (B1), riboflavin (B2), niacin (B3), calcium pantothenate (B5), pyridoxine (B6), biotin (B7), folic acid (B9), cobalamin (B12) and Vitamin C.
Supradyn is a Multivitamin tablet with minerals and trace elements. It contains 11 vitamins – A, B1, B2, B3, B5, B6, B7, B12, C, D3, and E. It contains 5 minerals – Manganese, Iron, Calcium, Phosphorus, and Magnesium.
It may also occur in people who follow a strict vegetarian (vegan) diet. Cyanocobalamin is available under the following different brand names: Vitamin B12, Nascobal, Athlete, Calomist, Cobalamin, Cobex, Crystamine, Prime, Rubramine PC, Vibisone, and Eligen B12.
Vitamin B12 injection:
It is used in people who do not get enough vitamin B12 from their diet or when their digestive tract does not absorb enough. Vitamin B12 plays an important role in maintaining the health of your nervous system and red blood cells.
Getting large amounts of vitamin B-12 through vitamin B-12 shots is not likely to harm your health. But vitamin B-12 may affect how well some drugs work. And some drugs can affect vitamin B-12 levels. So if you want to get vitamin B-12 shots, tell your health care provider first.
Vitamin B12 shots are very effective
The injections are prescribed by a doctor and given intramuscularly, or into muscle. Injections are usually given as hydroxocobalamin or cyanocobalamin. These are very effective at raising blood levels of B12 and preventing/reversing a deficiency.
Information compiled by
Dr.Bhairavsinh
