what is the rda for vitamin b12

What is the RDA for B12?

The Recommended Dietary Allowance (RDA) for vitamin B12 is based on the amount needed for the maintenance of hematological status and normal serum vitamin B12 values. An assumed absorption of 50 percent is included in the recommended intake. The RDA for adults is 2.4 μg/day of vitamin B12.

Is it OK to take 1000 mcg B12 daily?

Vitamin B12 dosage and frequency But dosages can vary depending on if you're treating severe, mild, or asymptomatic B12 deficiency. For vitamin B12 pills, most people take these daily in doses recommended by their doc but taking 1,000 mcg daily is pretty standard.

Can you have too much B12?

Since B12 is a water-soluble vitamin, it's generally considered safe, even at high doses. No Tolerable Upper Intake Level (UL) has been established for B12, due to its low level of toxicity. UL refers to the maximum daily dose of a vitamin unlikely to cause adverse side effects in the general population.

What happens when vitamin B12 is very high?

In some people, high levels of B12 may cause gastrointestinal problems such as bloating and diarrhea. And if you have high blood pressure or poor cardiovascular health, having too much B12 may further complicate these issues. Pregnant and breastfeeding women may also need to be especially mindful of B12 levels.

Can too much B12 cause neuropathy?

Thus, vitamin B12 may be associated with both sensory and motor peripheral nerve function. In older adults, the prevalence of poor peripheral nerve function and neuropathy is high and increases with age18–21.

Which fruit is rich in vitamin B12?

Banana is one of the best vitamin B12-rich fruits. Banana does contain vitamins and fibre, which helps in managing blood pressure, reducing stress, relieving constipation and ulcer problems. Banana has the power of controlling total body temperature.

What medications should not be taken with B12?

Certain medications can decrease the absorption of vitamin B12, including: colchicine, metformin, extended-release potassium products, antibiotics (such as gentamicin, neomycin, tobramycin), anti-seizure medications (such as phenobarbital, phenytoin, primidone), medications to treat heartburn (such as H2 blockers ...

What are the symptoms of low B12?

Vitamin B12 or folate deficiency anaemia can cause a wide range of symptoms. These usually develop gradually, but can worsen if the condition goes untreated.extreme tiredness (fatigue)lack of energy (lethargy)breathlessness.feeling faint.headaches.pale skin.noticeable heartbeats (palpitations)More items...

Is 1000 mcg B12 a lot?

In one 8-week study in 100 older adults, supplementing with 500 mcg of vitamin B12 were found to normalize B12 levels in 90% of participants. Higher doses of up to 1,000 mcg (1 mg) may be necessary for some ( 10 ).

What does 1000 mcg B12 mean?

Lifelong vitamin B12 supplements may be required at doses between 100 and 1,000 micrograms. As such, "B12 vitamin 1,000 mcg" refers to a high dose (1,000 micrograms) of vitamin B12 suitable for someone with nutrient absorption issues or pernicious anemia.

How much vitamin B12 should I take?

For people over 14, the RDI for vitamin B12 is 2.4 m cg ( 1 ).

How old do you have to be to take B12?

Due to this increased risk of poor absorption, the National Academy of Medicine recommends that adults over the age of 50 meet most of their vitamin B12 needs through supplements and fortified foods ( 1. Trusted Source.

How much B12 should vegans take?

However, one study suggests that doses up to 6 mcg of vitamin B12 per day may be appropriate for vegans ( 16 ).

How many vegetarians have low B12 levels?

In a review of 40 studies on vitamin B12 in vegetarians, up to 86.5% of vegetarian adults — including older adults — were found to have low levels of vitamin B12 ( 15 ).

What age group is most susceptible to vitamin B12 deficiency?

Adults over age 50. Older people are more susceptible to vitamin B12 deficiency. While relatively few younger adults are deficient in B12, up to 62% of adults over the age of 65 have less than optimal blood levels of this nutrient ( 8. Trusted Source.

How much B12 does the body absorb?

Note that the percent of vitamin B12 your body can absorb from supplements is not very high — it’s estimated that your body only absorbs 10 mcg of a 500-mcg B12 supplement ( 7 ).

What happens if you don't take enough B12?

Over time, B12 deficiency can lead to complications like anemia, nerve damage, and fatigue. Vitamin B12 deficiency can be caused by not getting enough of this vitamin through your diet, problems with absorbing it, or taking a medication that interferes with its absorption ( 4. Trusted Source.

What is the best source of vitamin B12?

Most of the best sources of vitamin B12 are animal products (like fish, meat, eggs and dairy products), so plant-based eaters are advised to take a daily vitamin B12 supplement to ensure that they get enough of the essential vitamin.

Why do we need B12?

Here’s a rundown of the top reasons why you need vitamin B12: 1 Helps maintain energy levels 2 Benefits memory and cognitive function 3 Promotes mood and stress regulation 4 Protects against heart disease 5 Boosts skin and hair health 6 Supports digestive health 7 Allows for proper growth and development (for fetuses, infants and children) 8 May reduce risk of certain cancers 9 Helps to prevent anemia

What is the best vitamin for a newborn?

The recommended daily vitamin B12 dosage for infants, children and teens is as follows: Vitamin B12 is essential for many body functions in babies, children and teens, including proper growth and brain function.

Why is vitamin B12 important for children?

Vitamin B12 is essential for many body functions in babies, children and teens, including proper growth and brain function. A deficiency is associated with an increased risk of adverse child health outcomes, according to research published in Advances in Nutrition.

How often is B12 given?

The dosage is typically decided by a doctor, and the injections are given at a clinic or doctor’s office. Injections are usually given weekly or monthly.

What is the percentage of people with pernicious anemia?

Pernicious anemia: This is a condition that affects about 1 percent to 2 percent of older adults. Because people with pernicious anemia cannot properly absorb vitamin B12 in the gastrointestinal tract, they are usually treated with vitamin B12 injections.

Why do vegans need B12?

Because most vitamin B12 foods come from animals, people following a vegan or vegetarian diet should take a B12 supplement in order to avoid deficiency.

What is the UL for vitamin B12?

UL: A Tolerable Upper Intake Level ( UL) is the maximum daily dose unlikely to cause adverse side effects in the general population. No upper limit has been set for vitamin B12, as there is no established toxic level. However, some evidence suggests that supplements of 25 mcg per day or higher may increase the risk of bone fractures. [2]

What percentage of the population has a vitamin B12 deficiency?

It is estimated that up to 15% of the general population has a vitamin B12 deficiency. [1] Factors that may cause vitamin B12 deficiency: Avoiding animal products. People who do not eat meat, fish, poultry, or dairy are at risk of becoming deficient in vitamin B12, since it is only found naturally in animal products.

What causes a deficiency of B12?

Intestinal surgeries or digestive disorders that cause malabsorption. Surgeries that affect the stomach where intrinsic factor is made, or the ileum (the last portion of the small intestine) where vitamin B12 is absorbed, can increase the risk of a deficiency. Certain diseases including Crohn’s and celiac disease that negatively impact the digestive tract also increase the risk of deficiency.

Why is B12 deficiency so common?

Inadequate stomach acid or medications that cause decreased stomach acid. A much more common cause of B12 deficiency, especially in older people, is a lack of stomach acid, because stomach acid is needed to liberate vitamin B12 from food.

What is the role of B12 in the body?

Vitamin B12 is needed to form red blood cells and DNA. It is also a key player in the function and development of brain and nerve cells. Vitamin B12 binds to the protein in the foods we eat. In the stomach, hydrochloric acid and enzymes unbind vitamin B12 into its free form. From there, vitamin B12 combines with a protein called intrinsic factor so ...

What vitamins are associated with hip fractures?

Meyer HE, Willett WC, Fung TT, Holvik K, Feskanich D. Association of High Intakes of Vitamins B6 and B12 From Food and Supplements With Risk of Hip Fracture Among Postmenopausal Women in the Nurses’ Health Study. JAMA network open. 2019 May 3;2 (5):e193591-.

Where is B12 absorbed?

From there, vitamin B12 combines with a protein called intrinsic factor so that it can be absorbed further down in the small intestine. Supplements and fortified foods contain B12 in its free form, so they may be more easily absorbed. There is a variety of vitamin B12 supplements available.

Overview

Vitamin B-12 (cobalamin) plays an essential role in red blood cell formation, cell metabolism, nerve function and the production of DNA, the molecules inside cells that carry genetic information.

Evidence

Research on the use of vitamin B-12 for specific activities and conditions shows:

Our take

Most people get enough vitamin B-12 from a balanced diet. However, older adults, vegetarians, vegans and people who have conditions that affect their ability to absorb vitamin B-12 from foods might benefit from the use of oral supplements.

Safety and side effects

When taken at appropriate doses, vitamin B-12 supplements are generally considered safe. While the recommended daily amount of vitamin B-12 for adults is 2.4 micrograms, higher doses have been found to be safe. Your body absorbs only as much as it needs, and any excess passes through your urine.

Interactions

Aminosalicylic acid (Paser). Taking this drug used to treat digestive problems might reduce your body's ability to absorb vitamin B-12.

What is the recommended B12 level for older adults?

For brain and nervous system health and prevention of disease in older adults, serum B12 levels should be maintained near or above 1000 pg/ml.”. The tragedy is with people who are symptomatic but are in the low range of vitamin B12 normal levels, between 200-500. This is a grey zone, and even though these folks show clinical signs ...

What is the normal B12 level?

Well, normal values of vitamin B12 are considered, in most countries, to be between around 200 to 900 pg/ml. However, as mentioned, many people show symptoms within that range. Therefore, we would like to suggest Sally Pacholok’s recommended vitamin B12 range: B12 Status. B12 Levels (pg/ml) Normal. 550 or higher.

What does B12 do to MMA?

B12 helps converting methylmalonyl CoA, one of the forms of MMA, into succinyl Coenzyme A . When you’re deficient in B12, MMA levels increase in both your blood and urine. You may be able to find MMA tests in private labs.

Why is methyl B12 needed?

Methyl B12 is needed as a co-factor to convert homocysteine back into methionine. If you have normal B12 values, but high homocysteine levels, this may point to a deficiency or problem utilizing methyl B12. High homocysteine levels can also be the result of low B6, folate, renal failure or hypothyroidism.

What is the best vitamin for iron storage?

By the way, we also recommend to test for folate (vitamin B9), ferritin (iron storage), and have a full blood count. This is because B12 and folate need each other, and optimal levels of iron are just as important as optimal B12 levels.

What percentage of B12 is inactive?

Inactive analogues of B12 (transcobalamin I and III) may represent as much as 80% of your blood levels. If a significant amount of your B12 is inactive, a test may show that you have normal B12 levels. Your body can’t easily access these forms. The blood test doesn’t record what’s happening at the cellular level.

Can B12 be used as an indicator?

In short, you can’t rely on serum B12 levels to tell you the whole story. But you can use it as an indicator of some sort. Let’s give you an actual chart.

How much B12 is safe?

Though doses of up to 2,000 mcg of vitamin B12 are considered safe, it’s best to speak to a doctor to find out whether taking a supplement is necessary.

Why is B12 important?

B12 is an important nutrient that is essential for red blood cell formation, DNA synthesis and many other vital processes. Supplements may help boost mood and reduce symptoms of depression in those who are not deficient in this vitamin.

How much B12 should I take daily?

For reference, the recommended daily intake (RDI) of vitamin B12 is 2.4 mcg for both men and women, though pregnant and breastfeeding women have a higher need ( 11. Trusted Source. ).

What is the UL of B12?

UL refers to the maximum daily dose of a vitamin unlikely to cause adverse side effects in the general population. This threshold has not been set for B12 because your body excretes whatever it doesn’t use through your urine. However, supplementing with excessively high levels of B12 has been linked to some negative side effects.

What are the benefits of B12?

For example, studies show that supplemental B12 may benefit people without a deficiency in the following ways: 1 Improved mood: One study found that supplementing healthy men with a B-complex vitamin containing a high dose of B12 improved ratings of stress and enhanced performance on cognitive tests ( 3#N#Trusted Source#N#). 2 Reduced symptoms of anxiety and depression: Treatment with a supplement containing a high dose of B12 for 60 days significantly improved depression and anxiety symptoms in adults when compared to a placebo ( 4#N#Trusted Source#N#).

How long does B12 help with anxiety?

Reduced symptoms of anxiety and depression: Treatment with a supplement containing a high dose of B12 for 60 days significantly improved depression and anxiety symptoms in adults when compared to a placebo ( 4. Trusted Source. ).

What to do if you are deficient in B12?

If you think you may be deficient in B12, speak with your doctor, who can recommend an appropriate treatment based on your level of deficiency. While no UL has been set for B12, your body’s ability to absorb the vitamin depends on how much it actually needs.

How to take vitamin B12?

Vitamin B12 deficiency. Vitamin B12 can treat and prevent vitamin B12 deficiency. It can be taken by mouth, as a shot, or inhaled through the nose. The shot works best in people with severe vitamin B12 deficiency and in those not able to take vitamin B12 by mouth.

What is B12 used for?

It is often taken in combination with other B vitamins. Vitamin B12 is most commonly used for vitamin B12 deficiency, a condition in which vitamin B12 levels in the blood are too low, as well as cyanide poisoning and high levels of homocysteine in the blood (hyperhomocysteinemia).

How long does it take to take B12 for schizophrenia?

Schizophrenia. Early research shows that taking vitamin B12 with folic acid daily for 16 weeks can improve symptoms of schizophrenia related to abnormal emotions and behavior. But the treatment only seems to benefit some patients.

What is the purpose of B12?

Vitamin B12 is required for the proper function and development of the brain, nerves, blood cells, and many other parts of the body.

Does B12 help with osteoporosis?

Taking vitamin B12 and folic acid, with or without vitamin B6 daily for 2-3 years does not seem to reduce the risk of fractures in older people with osteoporosis.

Does B12 help with sleep?

Taking vitamin B12 by mouth does not seem to help people with sleep disorders. Memory and thinking skills (cognitive function). Taking vitamin B12, alone or with folic acid and vitamin B6, doesn't seem to improve memory, language, or the ability to organize and plan in elderly people. Fall prevention.

Does vitamin B12 help with memory loss?

Decline in memory and thinking skills that occurs normally with age. One study shows that taking vitamin B6, folic acid, and vitamin B12 might help prevent certain parts of the brain from deteriorating in elderly people. But most research shows that taking these vitamins does not improve mental function in elderly people.

What Is Vitamin B12?

Vitamin B12, also known as cobalamin, is an essential vitamin that your body needs to function properly. It’s found in dairy products such as yogurt, milk, and cheese as well as in meat, fortified cereals, and fish. Beef, pork, lamb, poultry, and ham are all rich sources of vitamin B12. Vitamin B12 supplements are also created in labs through bacterial fermentation. Since natural vitamin B12 comes mainly from animal sources, vegans typically need to use a supplement to get proper amounts of the nutrient.

What is the role of vitamin B12 in the body?

Vitamin B12 helps to create and reproduce blood cells and is also involved in producing energy.

Why are seniors at higher risk for vitamin B12 deficiency?

That’s because this disorder makes it hard for your body to produce intrinsic factor (IF), a protein that plays a key role in the absorption of vitamin B12.

How to diagnose vitamin B12 deficiency?

How To Diagnose a Vitamin B12 Deficiency. The best way to see if you have a vitamin B12 deficiency is to visit your healthcare provider and take a blood test. On the day of your visit, your doctor will ask you about your medical history and draw blood to determine your B12 levels in blood serum.

What are the most common dietary deficiencies for seniors?

As a result, many older adults suffer from vitamin deficiencies that can cause health problems. The most common dietary deficiencies for seniors include calcium, vitamin D, magnesium, vitamin E, and B vitamins. B vitamins are particularly important ...

Why is B12 important for seniors?

Vitamin B12 is particularly important because it plays a role in brain function, metabolism, nerve cells, and blood health. Vitamin B12 helps to metabolize an amino acid known as homocysteine.

What happens if you don't get enough B12?

When you don’t get enough vitamin B12 or you have a folate deficiency, your organs suffer from a lack of oxygen, meaning they function less effectively. The result is known as megaloblastic anemia, a disorder where your body produces inadequate red blood cells.

Recommended Amounts

See more on hsph.harvard.edu

Vitamin B12 and Health

Signs of Deficiency and Toxicity

Did You Know?

Terms of Use