Vitamin B12 - Health Professional Fact Sheet

Vitamin B12 is an essential nutrient that plays a crucial role in overall health maintenance. It is a water-soluble vitamin found naturally in certain foods and also available as a dietary supplement. Vitamin B12 is required for red blood cell formation, nerve function, and the synthesis of DNA. In addition, it plays a crucial role in the metabolic processes of every cell in the body.

Vitamin B12 is unique among vitamins in that it is produced by microorganisms rather than plants or animals. Vitamin B12 is obtained by animals, including humans, from microorganisms present in animal-based foods or from supplements. Vegans and vegetarians are at risk of vitamin B12 deficiency because the only reliable sources of the vitamin are animal products.

Vitamin B12 deficiency can result in a variety of symptoms, many of which are easily missed or attributed to other causes. Among these symptoms are fatigue, weakness, constipation, appetite loss, weight loss, and nerve damage. A deficiency can also result in pernicious anemia, which can cause shortness of breath, numbness and tingling in the hands and feet, and an enlarged liver and spleen, among other symptoms. Long-term deficiency can also cause irreversible nervous system damage.

Vitamin B12 is stored in the liver, so a deficiency may not occur for a considerable period of time even if intake is insufficient. However, as people age, their ability to absorb Vitamin B12 from food diminishes, putting many seniors at risk for deficiency.

Noting that Vitamin B12 deficiency can have severe health consequences, it is always advisable to consult a healthcare professional if you suspect a deficiency. However, a simple blood test can determine whether or not a deficiency exists, and if it does, a treatment plan can be developed that may involve dietary changes, supplements, or in some cases, injections.

Type of Vitamin B12

Vitamin B12 is a water-soluble vitamin that is available in multiple forms. These are the most prevalent forms of Vitamin B12 found in dietary supplements and fortified foods:

• This is the most prevalent form of Vitamin B12 found in dietary supplements and fortified foods. Before the body can use cyanocobalamin, it must be converted to the active forms of Vitamin B12, methylcobalamin and adenosylcobalamin.

• Methylcobalamin: This is a form of vitamin B12 that the body readily utilizes. It is commonly found in Vitamin B12 supplements and is also offered as an injection.

• Adenosylcobalamin is another active form of vitamin B12 that the body readily utilizes. In addition to being a supplement ingredient, it is also available as an injection.

• This is another injectable form of vitamin B12, hydroxocobalamin. It is converted in the body to active forms of vitamin B12.

Notably, the form of Vitamin B12 you choose to take may depend on your individual needs and the recommendations of your healthcare professional. Some individuals may have difficulty absorbing certain Vitamin B12 forms and may require a different form. Methylcobalamin and adenosylcobalamin are the active forms of vitamin B12 that the body can use directly.

Type of Vitamin B12 Supplements

Multiple forms of vitamin B12 supplements are available, including:

• Oral supplements are the most prevalent form of Vitamin B12 supplements and are available in tablet, capsule, and liquid form. They are orally administered and readily absorbed by the body.

• Sublingual supplements are supplements that are dissolved under the tongue and consumed. They are thought to be more easily absorbed by the body than oral supplements because they bypass the digestive tract.

• Transdermal patches: Vitamin B12 Patches are also available in the form of skin-applied transdermal patches. Vitamin B12 is absorbed into the bloodstream through the skin.

• Injections: Vitamin B12 can also be administered via injection, which is a common method for individuals with certain medical conditions or who have trouble absorbing Vitamin B12 from food or supplements.

It is important to note that the form of Vitamin B12 supplement that is most suitable for an individual may depend on their unique needs and the recommendation of a healthcare professional. Some individuals may have difficulty absorbing certain Vitamin B12 forms and may require a different form. Because they are directly absorbed into the bloodstream, sublingual administration and injections are considered to have a greater bioavailability than oral supplements.

Recommended Intakes

Adults are advised to consume 2,4 micrograms of vitamin B12 daily. This requirement can be easily met by consuming a varied diet that includes fish, meat, poultry, eggs, and dairy products. However, vegans and vegetarians may not consume sufficient Vitamin B12 and may require supplements or fortified foods to meet their needs.

It is recommended that pregnant and lactating women consume 2,6 and 2,8 micrograms of vitamin B12 each day. This is due to the increased need for vitamin B12 during pregnancy and lactation, as it is required for fetal development and the production of breast milk.

These recommended intake values are based on average daily intake levels that are sufficient to meet the needs of the vast majority of healthy individuals. Nevertheless, some individuals may require more or less Vitamin B12, depending on their age, gender, and overall health. Therefore, it is always advisable to consult a healthcare professional to determine an individual's optimal intake level.

In addition, while Vitamin B12 is relatively non-toxic, high doses can cause acne and interfere with certain laboratory tests. Prior to taking any dietary supplements, it is crucial to consult a healthcare professional.

Sources of Vitamin B12

Vitamin B12 is naturally present in a wide range of animal-based foods, including fish, meat, poultry, eggs, and dairy products. These are the most reliable dietary sources of Vitamin B12 because they contain the readily absorbable active form of Vitamin B12.

Good sources of Vitamin B12 include beef, chicken, lamb, pork, fish (such as salmon, tuna, and cod), and seafood (such as clams, oysters, crab, and lobster). Vitamin B12 is also abundant in milk, cheese, and yogurt, among other animal products.

Additionally, certain breakfast cereals, plant-based milk alternatives, and nutritional yeast are fortified with vitamin B12. These fortified foods typically contain Vitamin B12 in the form of cyanocobalamin, which the body can convert into the active form of Vitamin B12. Notably, fortified foods may not be as easily absorbed by the body as Vitamin B12 derived from animal sources.

Fortified foods and supplements may be the only reliable source of Vitamin B12 for vegetarians and vegans. In order to prevent deficiency, vegans and vegetarians must consume sufficient Vitamin B12 through fortified foods or supplements.

It is important to note that certain medical conditions or medications may prevent some individuals from absorbing Vitamin B12 from food. In these instances, a Vitamin B12 injection or supplement may be required to meet the body's needs. Therefore, it is always prudent to consult a healthcare professional for individualized advice on Vitamin B12 sources.

Vitamin B12 Intakes and Status

Vitamin B12 is stored in the liver, so a deficiency may not occur for a considerable period of time even if intake is insufficient. However, as people age, their ability to absorb Vitamin B12 from food diminishes, putting many seniors at risk for deficiency. People with certain medical conditions, such as atrophic gastritis, or who have undergone weight-loss surgery may have trouble absorbing Vitamin B12 from food and are at risk for deficiency.

Additionally, vegans and vegetarians are susceptible to Vitamin B12 deficiency because they do not consume animal-based foods, which are the most reliable dietary sources.

Vitamin B12 can be stored in the body for several years, so deficiency may not occur immediately after inadequate intake. However, a deficiency can have severe health consequences, so it's always advisable to consult a healthcare professional if you suspect you have one.

A simple blood test can determine the Vitamin B12 status of the body by measuring the level of Vitamin B12 in the blood and the level of intrinsic factor, a protein that aids in Vitamin B12 absorption. The test results will indicate whether the levels of vitamin B12 are normal, low, or deficient.

To ensure proper red blood cell formation, nerve function, and DNA synthesis, it is essential to maintain adequate levels of vitamin B12. Low levels of vitamin B12 can cause anemia and damage to the nervous system. To avoid deficiency and maintain optimal health, it is essential to consume a balanced diet that includes a variety of Vitamin B12-rich foods, or to take supplements as directed by a healthcare professional.

Vitamin B12 Deficiency

A deficiency in vitamin B12 is a condition in which the body lacks sufficient vitamin B12 to support normal bodily functions. It can occur when the body does not absorb enough vitamin B12 from food or when insufficient vitamin B12 is ingested.

Vitamin B12 deficiency is characterized by fatigue, weakness, constipation, appetite loss, weight loss, and nerve damage. In addition, a deficiency can result in pernicious anemia, which can cause a variety of symptoms, including shortness of breath, numbness and tingling in the hands and feet, and a swollen liver and spleen. Long-term deficiency can also cause irreversible nervous system damage.

Vegetarians and vegans, people with gastrointestinal disorders such as atrophic gastritis, and those who have undergone weight loss surgery are at high risk for Vitamin B12 deficiency. Due to decreased absorption of Vitamin B12 from food, the elderly also have an increased risk of deficiency.

Vitamin B12 deficiency can be treated with vitamin B12 supplements, vitamin B12 injections, and dietary modifications to include more vitamin B12-rich foods. A healthcare professional can recommend the most appropriate treatment based on the specific needs of the individual.

Groups at Risk of Vitamin B12 Inadequacy

There are certain populations at a greater risk for Vitamin B12 deficiency, including:

• Vegans and vegetarians are susceptible to Vitamin B12 deficiency because they do not consume animal-based foods, which are the most reliable dietary sources of Vitamin B12.

• Certain medical conditions, such as atrophic gastritis, can impair the body's ability to absorb Vitamin B12 from food, putting individuals at risk for insufficiency.

• As people age, their ability to absorb Vitamin B12 from food declines, putting them at a greater risk for deficiency.

• Patients who have undergone weight-loss surgery: Surgical procedures involving the gastrointestinal tract, such as gastric bypass or sleeve gastrectomy, can impair the body's ability to absorb Vitamin B12 from food, putting patients at risk for deficiency.

• Certain medications, such as proton pump inhibitors and metformin, can interfere with the body's ability to absorb Vitamin B12, putting individuals at risk for insufficiency.

It is essential for these groups to be aware of their increased risk for Vitamin B12 deficiency and to take steps to ensure adequate intake through dietary changes, fortified foods, or supplements as directed by a healthcare professional.

Vitamin B12 and Health

Vitamin B12 consumption is essential for maintaining overall health. Vitamin B12 is essential for red blood cell production, DNA synthesis, and the proper functioning of the nervous system.

• Formation of oxygen-carrying red blood cells: Vitamin B12 is required for the formation of red blood cells, which transport oxygen throughout the body. Vitamin B12 deficiency can result in pernicious anemia, which is characterized by symptoms such as fatigue, weakness, and shortness of breath.

• Vitamin B12 is essential for maintaining the health of the nervous system, which is essential for its proper functioning. Vitamin B12 deficiency can cause nerve damage, manifesting as numbness and tingling in the hands and feet.

• Vitamin B12 is required for DNA synthesis, the genetic material that contains the instructions for the development and function of all living organisms.

• Recent studies have also demonstrated that adequate levels of vitamin B12 may reduce the risk of certain types of cancer. According to the studies, a diet high in vitamin B12 may reduce the risk of colorectal cancer.
• Vitamin B12 is essential for the production of neurotransmitters, which are chemicals in the brain that help to regulate mood. Low Vitamin B12 levels have been associated with depression and cognitive decline.

To ensure proper red blood cell formation, nerve function, and DNA synthesis, it is essential to maintain adequate levels of vitamin B12. Low levels of vitamin B12 can cause anemia and damage to the nervous system. To avoid deficiency and maintain optimal health, it is essential to consume a balanced diet that includes a variety of Vitamin B12-rich foods, or to take supplements as directed by a healthcare professional.

Health Risks from Excessive Vitamin B12

Vitamin B12 is relatively non-toxic; however, excessive amounts can cause acne and interfere with certain laboratory tests. Extremely rare instances of vitamin B12 toxicity can result from consuming excessive amounts of vitamin B12 from supplements or fortified foods.

1. Acne: High doses of Vitamin B12 can cause acne in some people, as it can increase the production of sebum which can clog pores and lead to the formation of pimples.
   
   
2. High levels of vitamin B12 can interfere with certain laboratory tests, such as those for liver function, kidney function, and certain cancers, making it difficult to obtain accurate test results.
   
   
3. Interactions with Medications: High levels of vitamin B12 can interact with certain medications, such as antibiotics and blood thinners, causing side effects and decreasing the efficacy of the medications.

It is important to note that these risks are associated with excessive vitamin B12 consumption from supplements and fortified foods. A balanced diet containing a variety of Vitamin B12-rich foods is considered safe and poses no risk of toxicity. However, it is always a good idea to consult a healthcare professional before taking dietary supplements, particularly if you are currently taking medication.

Interactions with Medications

Vitamin B12 can interact with certain medications, resulting in adverse side effects and diminished efficacy. It is important to be aware of these interactions and to inform your healthcare provider if you are taking any medications and are considering taking a Vitamin B12 supplement or consuming more Vitamin B12 in your diet.

Certain antibiotics, such as metronidazole and neomycin, can inhibit Vitamin B12 absorption. If not corrected, this can result in a deficiency and symptoms of anemia.

Long-term use of proton pump inhibitors, a class of drugs used to treat acid reflux, can impair Vitamin B12 absorption.

Metformin, a drug used to treat diabetes, can inhibit Vitamin B12 absorption. Metformin users may be at increased risk for Vitamin B12 deficiency.

Vitamin B12 in high doses can interfere with the effectiveness of blood-thinning medications such as warfarin. This increases the possibility of blood clots and bleeding.

It is essential to keep in mind that these interactions may vary depending on the individual and the medication being taken. Always seek personalized advice from a healthcare professional regarding interactions between medications and Vitamin B12.

Vitamin B12 and Healthful Diets

Vitamin B12 is an essential nutrient that plays a crucial role in overall health maintenance. To ensure proper bodily functions, it is essential to consume adequate amounts of Vitamin B12 through a healthy and balanced diet.

• Fish, meat, poultry, eggs, and dairy products are the most reliable sources of vitamin B12 in the diet. These foods contain an easily absorbable active form of vitamin B12.

• Certain breakfast cereals, plant-based milk alternatives, and nutritional yeast are fortified with cyanocobalamin, which the body can convert into the active form of Vitamin B12.

• Individuals who may have difficulty obtaining enough Vitamin B12 from their diet, such as vegetarians and vegans, or those with certain medical conditions, may require Vitamin B12 supplements to meet their body's needs.

• Vitamin B12 deficiency can be prevented and optimal health can be maintained by consuming a balanced diet that includes a variety of Vitamin B12-rich foods or by taking supplements as directed by a healthcare professional.

It is important to note that the recommended daily intake of Vitamin B12 for adults is 2.4 micrograms, while pregnant and lactating women have a higher requirement and should consume 2.6 and 2.8 micrograms, respectively. Always seek the advice of a healthcare professional when determining an individual's optimal intake level.

References

• Institute of Medicine (US) Panel on Micronutrients. (1998). Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. National Academies Press (US).
• "Vitamin B12." Office of Dietary Supplements - National Institutes of Health, U.S. Department of Health and Human Services, ods.od.nih.gov/factsheets/VitaminB12-Consumer/.
• "Vitamin B12 Deficiency: Causes, Symptoms, and Diagnosis." Medical News Today, MediLexicon International, www.medicalnewstoday.com/articles/325918
• "Vitamin B12." MedlinePlus, U.S. National Library of Medicine, medlineplus.gov/vitaminb12.html.
• "Vitamin B12." Healthline, Healthline Media, www.healthline.com/health/vitamin-b12-deficiency#symptoms
• "Vitamin B12 and Cancer Prevention." American Cancer Society, American Cancer Society, www.cancer.org/content/dam/cancer-org/research/cancer-facts-and-statistics/vitamin-b12-and-cancer-prevention.pdf