Vitamin B12
Vitamin B12
Vitamin B12 is a water-soluble vitamin that is naturally present in some foods. Vitamin B12 contains the mineral cobalt; compounds with vitamin B12 activity are collectively called “cobalamins.” Vitamin B12 is essential for the development, myelination, and function of the central nervous system; healthy red blood cell formation; and DNA, RNA, proteins, and lipids synthesis.
What is Vitamin B12?
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Vitamin B12 is an essential water-soluble vitamin vital in our body’s metabolism.
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Vitamin B12 is an essential nutrient vital for health and mental health
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Vitamin B12 is a nutrient that helps keep nerve and blood cells healthy and helps make DNA. DNA is the genetic material in all of our cells.
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Because vitamin B12 contains the mineral cobalt, compounds with vitamin B12 activity are collectively called “cobalamins”.
Vitamin B12 | Vitamin B12 for cell division and growth.
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Vitamin B12 is one of the eight B vitamins essential in making human blood cells, DNA synthesis, cell division and growth, and fat and protein metabolisms. In addition, vitamin B12 works with vitamin B9-folate to make red blood cells.
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Vitamin B12 is the most chemically complex of all vitamins, and vitamin B12 molecule contains mineral cobalt ion in its molecule. Therefore, vitamin B12 is the only vitamin that must be sourced from animal-derived foods because natural plant-based foods do not contain vitamin B12.
Vitamin B12 | vitamin B12 is the essential nutrient for health and mental health.
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Vitamin B12 is essential in maintaining the human nervous system and mental health.
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Vitamin B12 is a key player in the function and development of brain and nerve cells. Vitamin B12 is required for the central nervous system's development, myelination, and function.
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Vitamin B12 is vital in the regular nervous system operation via its role in myelin synthesis. Myelin is a white fatty substance that forms a medullary sheath around the axis cylinder of nerve fibers.
The Absorption of Vitamin B12
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In natural foods, vitamin B12 is bound to protein in food and then released after intake before our bodies absorb it. The vitamin B12-releasing process starts in the mouth when food is mixed with saliva, and more is released in the gastrointestinal tract.
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The body absorbs vitamin B12 from natural foods in a 2-step process.
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First, hydrochloric acid in the stomach separates vitamin B12 from the protein that it is attached to.
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Second, the freed vitamin B12 combines with a protein made by the stomach, called intrinsic factor, and the body absorbs them together. The intrinsic factor is a protein the stomach makes and is needed to absorb vitamin B12 in the small intestine.
The nutritional sources of vitamin B12
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Vitamin B12 is naturally present in foods of animal origin, including dairy products, eggs, poultry, meat, and fish.
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In natural foods, vitamin B12 binds to protein in these foods. However, vitamin B12 is in its free form with high bio-availability in vitamin B12-fortified products such as fortified breakfast cereals and nutritional yeasts.
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Fortified breakfast cereals and fortified nutritional yeasts are readily available sources of vitamin B12 with high bio-availability.
"Fortified": What does "fortified" mean?
"fortified" means foods to which nutrients are added that were not present originally or nutrients are added that increase the amount already present.
How much vitamin B12 do I need?
The average recommended daily amounts (RDA) for different ages are in the microgram (mcg) unit.
For people 14 years and older, the RDA of vitamin B12 is 2.4 micrograms daily.
For pregnant teens (14-18 years old) and women (19 to 50 years old), the RDA is 2.6 micrograms daily; for breastfeeding teens (14-18 years old) and women (19 to 50 years old), the RDA of vitamin B12 is 2.8 micrograms daily.
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What does RDA mean?
The Recommended Dietary Allowance (RDA) is the average daily intake sufficient to meet the nutrient requirements of nearly all (97%-98%) healthy individuals.
The food sources of vitamin B12
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Natural Plant foods have no vitamin B12 unless fortified with vitamin B12.
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Vitamin B12 is found naturally in a wide variety of animal foods. In addition, some manufactured food products are fortified with vitamin B12.
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You can get vitamin B12 by eating a variety of foods, including the following:
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Beef liver and clams are some of the best sources of vitamin B12.
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Meat, poultry, fish, eggs, milk, and other dairy products contain vitamin B12.
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Some breakfast cereals, nutritional yeast, and other food products are fortified with vitamin B12.
Top vitamin B12 foods for health and mental health:
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Beef liver
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Clams (without shells)
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Tuna bluefin
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Nutritional yeast, fortified (check label)
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Salmon
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Meat
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Milk
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Yogurt
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Eggs
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Turkey breast meat
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Chicken breast meat
Vegans and Vegetarians and vitamin B12
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Vitamin B12 is the only vitamin that must be sourced from animal-derived foods.
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People who eat little or no animal foods, such as vegetarians and vegans, might need more vitamin B12 from their diets because only animal foods have vitamin B12 naturally. In addition, when pregnant women and women who breastfeed their babies are strict vegetarians or vegans, their babies might not get enough vitamin B12. Consuming foods fortified with vitamin B12 or dietary supplements can prevent vitamin B12 deficiency.
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Because the body can store about 1-5 milligrams of vitamin B12, the symptoms of vitamin B12 deficiency can take several years to appear. The daily recommended intake of vitamin B12 for adults is 2.4 micrograms. Therefore, the body's storage of vitamin B12 is about 1000 to 2000 times as much as the amount typically consumed daily. This is the reason that vitamin B12 deficiency can take years to appear.
Vitamin B12 and Healthful Diets:
Our nutritional needs should be met primarily through foods because foods provide various nutrients and other healthy components. Foods contain vitamins, minerals, dietary fiber, and other nutrients that are beneficial for our health. In some situations and cases, fortified foods and dietary supplements are helpful when it is impossible to meet the needs for one or more nutrients.
A healthy dietary pattern was described by “The Dietary Guidelines for Americans” as one that:
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Includes a variety of vegetables; fruits; grains, and whole grains; milk, yogurt, cheese; and oils. Milk and yogurt are rich food sources of vitamin B12. Breakfast cereals, fortified with vitamin B12, are good food sources of vitamin B12.
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Includes various protein foods, such as lean meats; poultry; eggs; seafood; beans, peas, lentils; nuts and seeds; and soy products. Beef liver is rich in vitamin B12. Red meat and fish are excellent sources of vitamin B12. Eggs and poultry also contain vitamin B12.
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Limits foods and beverages higher in added sugars, saturated fat, and sodium. Limits alcoholic beverages.
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Stays within your daily calorie needs.
References:
https://ods.od.nih.gov/factsheets/Folate-HealthProfessional/, updated on November 30, 2022
Institute of Medicine. Food and Nutrition Board. Dietary Reference Intakes: Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. Washington, DC: National Academy Press; 1998.
Dietary Reference Intakes: The Essential Guide to Nutrient Requirements (2006) ISBN 978-0-309-10091-5 | DOI 10.17226/11537
Bailey LB, Caudill MA. Folate. In: Erdman JW, Macdonald IA, Zeisel SH, eds. Present Knowledge in Nutrition. 10th ed. Washington, DC: Wiley-Blackwell; 2012:321-42.
Carmel R. Folic acid. In: Shils M, Shike M, Ross A, Caballero B, Cousins RJ, eds. Modern Nutrition in Health and Disease. 11th ed. Baltimore, MD: Lippincott Williams & Wilkins; 2005:470-81.
https://www.dietaryguidelines.gov/
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