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How Much Vitamin B12 Should You Take Per Day

Preventing Vitamin B12 Deficiency

How Much B12 Should We Take?

If you take metformin, a yearly check of your vitamin B12 status can alert your doctor to any dips in your levels that may be early signs of a deficiency. One way to determine vitamin B12 status is with a test that directly measures levels of B12 in a blood sample. A more sensitive test looking at levels of a metabolite in the blood called methylmalonic acid may be able to detect low B12 levels earlier.

Meanwhile, including plenty of foods rich in vitamin B12 in your diet, such as eggs, beef, salmon, chicken, and nutritional yeast and/or taking supplemental B12 may help to prevent a deficiency .

The methylcobalamin form of vitamin B12 in a sublingual format is best absorbed by the body, but you should consult your doctor about the ideal supplement and correct dosage for you.

Heart Beat: Diabetes Drug Interferes With Vitamin B12

Metformin is a first-line drug for treating type 2 diabetes. It limits the amount of sugar the body absorbs from food, cuts down on the amount of sugar the liver produces, and makes muscles and other tissues more sensitive to insulin, the hormone that ushers blood sugar into cells. Although metformin is very safe, one-third of those who take it develop low levels of circulating vitamin B12. The body needs this vitamin to make new red blood cells and to keep nerve cells healthy. In a Canadian study, diabetics taking metformin had half the blood levels of vitamin B12 of those who werent taking metformin 31% of the metformin takers had levels significantly below normal. They also had more advanced neuropathy, the degeneration of nerves that often accompanies diabetes .

Older people are prone to vitamin B12 deficiency because aging reduces the bodys ability to absorb this vitamin from food adding metformin can worsen the problem. A severe deficiency can lead to anemia and confusion, and sometimes masquerades as dementia or Alzheimers disease.

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What You Can Do

  • If you have been taking metformin for several years, ask your health care provider to have your vitamin B12 level measured, and ask what your level should be.
  • If you have symptoms of a vitamin B12 deficiency, including neuropathy, let your provider know and ask to have your B12 level measured.
  • If your level is below target, talk with your provider about treatment options. You may be able to take a daily B12 supplement, for example, rather than receiving B12 injections.
  • Certain medications can affect B12 levels, including proton pump inhibitors, such as omeprazole and lansoprazole and histamine 2-receptor antagonists, such as cimetidine and ranitidine . Let your provider know if you are taking any of these medications.
  • Because older adults are at risk of a vitamin B12 deficiency, start getting regular blood tests for this when you are in your 60s. Some health experts recommend that older adults take a daily B12 supplement.
  • Eat foods that contain vitamin B12. If you follow a vegetarian or vegan eating pattern, focus on eating foods fortified with vitamin B12 or consider taking a multivitamin.

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What Is Vitamin B12

Vitamin B12, also known as cobalamin, is an essential vitamin that your body needs to function properly. Its 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.

This vitamin plays a key role in creating red blood cells and producing nerve tissue that helps transmit signals from the brain to cells. Vitamin B12 is water-soluble and travels through your bodys bloodstream to aid in cell function.

The Right Dose Is The Key To Vitamin B12 Deficiency Treatment

Vitamin B12 Dosage: How Much Should You Take per Day?

Getting the right KIND of vitamin B12 is just the first step. As I said earlier, it’s likely that your doctor will recommend a vitamin b 12 dosage of 1000 micrograms per day. While studies have shown that this dose is effective to bring up vitamin B12 BLOOD LEVELS, the Facts about Vitamin B12 show that that this is often not a high enough vitamin b 12 dosage to make people feel as well as they could- andTHAT is what is important to YOU.

One study entitled Vitamin B-12: Placebo or Neglected Therapeutic Tool had people who felt fatigued, but had NORMAL vitamin B12 blood levels and kept giving higher doses of supplements until they had a ‘maximum feeling of well being’. And the AVERAGE dose that it took to do this was 9000 micrograms per day, that is 9 milligrams. And that was the AVERAGE dose, this means that some people needed even higher doses than this to feel well. And these were people without a diagnosed vitamin B12 deficiency!

So, if you truly have Vitamin B12 deficiency, then you may need even more than these study participants!

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What Are B12 Injections And Should I Try Them

Yes, B12 injections may have had a moment in the spotlight, but it’s not really advisable for the average person, Keatley says. If you’re not getting enough B12 in your diet, injections may be helpful if you are, they’re unlikely to do anything. What’s more, being deficient in B12 doesn’t mean you automatically have to have regular shots since some people do just fine with supplements in pill form, Keatley says. But if you have pernicious anemia or have any other trouble absorbing B12, injections might be a good idea for you, Warren says.

Can High Levels Of Vitamin B12 Become Dangerous To Seniors

The good thing about vitamin B12 treatment is that its extremely unlikely to overdose on vitamin B12. Unlike some other vitamins, vitamin B12 doesnt cause toxicity when levels are high.

If your parent is being treated for vitamin B12 deficiency, you dont need to worry that the doctors will overshoot. You just need to make sure a follow-up test has confirmed better vitamin B12 levels. Your family can then work with the doctors to find the right maintenance dose to prevent future vitamin B12 deficiency.

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What Promotes Nerve Healing

The team at the Department for Cell Physiology headed by Professor Dietmar Fischer showed that, under certain conditions, a protein is formed in injured nerve cells of the CNS that had previously only been described in muscle cells. In experiments, the muscle LIM protein promoted the regeneration of damaged nerves.

Why Does Vitamin B12 Deficiency Occur With Long

Vitamin B12 – How Often & The Dangers Of Taking Too Much

Its thought that metformin possibly interferes with absorption of the vitamin in the digestive tract. Of note, the body stores between 1,000 and 2,000 times as much vitamin B12 as one would typically eat in a day for this reason, symptoms of vitamin B12 deficiency can take several years to appear.

The American Diabetes Association recommends that people taking metformin periodically have their B12 status assessed, as a deficiency may contribute to anemia or peripheral neuropathy. Vitamin B12 status is assessed by a blood test.

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What Does Vitamin B12 Do

Vitamin B12, or cobalamin has many crucial roles. It works to maintain nerve cells, keep your brain healthy and is also involved in energy production. It is key in red blood cell formation, blood function and the creation of DNA, too. Plus, it prevents a serious type of anaemia called megoblastic anaemia.

What Is Cyanocobalamin Tablets And How Does It Work

  • Cyanocobalamin or vitamin B12 is an essential B-vitamin that is classified as a water-soluble vitamin. Food sources of vitamin B12 include fish, shellfish, meats, and dairy products. Vitamin B12 is necessary for growth, reproduction of cells (for example, production of red blood cells, and the production of myelin that protects nerves and proteins within the nucleus of cells. Vitamin B12 also plays an important role in the breakdown or metabolism of fats and carbohydrates and production of proteins. Vitamin B12 deficiency may result in anemia, gastrointestinal problems, and nerve damage.

What brand names are available for cyanocobalamin tablets?

Vitamin B12, B12

Is cyanocobalamin tablets available as a generic drug?

Do I need a prescription for cyanocobalamin tablets?

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What Happens If You Dont Get Vitamin B12

There are serious consequences of Vitamin B12 deficiency. What you mightnt realise, however, is that your liver stores of Vitamin B12 can last up to five years, so it takes a long time for deficiency to occur. Whats more, the cause of deficiency is usually malabsorption rather than inadequate dietary intake.

Nonetheless, Vitamin B12 deficiency can result in tiredness, reduced energy levels and gut symptoms. The more severe outcomes of Vitamin B12 deficiency are vision loss, memory loss and even heart palpitations.

The people who have the highest risk of this serious deficiency are the elderly, those who follow a vegan diet and breast-fed babies of vegan mothers .

The Two Forms Of Vitamin B12 You Need To Know

How Much Vitamin B

Vitamin B12 is the largest and most complex vitamin we know today. In supplements, it comes in two primary forms: methylcobalamin or cyanocobalamin.

These two forms differ in a couple of key areas explained below.


Methylcobalamin is the best absorbed form of supplemental B12 in the body because it is bioactive. In other words, its readily available to positively interact with our cells.

This form has a chemical structure that has a methyl group, which consists of a hydrogen and oxygen molecule. This methyl group makes it the most active form of Vitamin B12 in the body.

Methylcobalamin is also the most common form of B12 found in animal foods, which is why meat eaters dont need to supplement.


The only synthetic form of Vitamin B12, cyanocobalamin differs greatly than other forms because its chemical structure contains cyanide.

This cyanide group is the same as the poisonous cyanide youve heard of before, but irrelevant to the body at the levels found in Vitamin B12. It is also the only form of Vitamin B12 that gets created in a lab setting.

The synthetic nature of this form requires more steps in the breakdown of Vitamin B12 and could potentially cause absorption issues.

Cyanocobalamin is used in supplements for years due to its proposed effectiveness. Although more recently, criticisms in the scientific community have started to surface about its:

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Study Participants And Baseline Characteristics

Study participants had an average age of 60.0 years , 6713 were male and 9986 were female . Participants had an average vitamin B12 level of 295.9pmol/L , 257 participants had vitamin B12 deficiency, while 10468 participants did not consume meat. The mean FBG level was 5.8mmol/L at baseline, and the exit mean FBG level was 6.3mmol/L . At baseline, 1872 participants had DM, and at the exit visit there were 1589 cases of new-onset DM. When stratified by baseline vitamin B12 quartiles, FBG levels were the highest ) in the fourth quartile . shows that the average age and BMI of the participants in Q4 were lower than those of the other groups, but TC and TG levels were higher than the other quartiles.

Multivariable-adjusted smoothing curves of change in vitamin B12 and change in FBG in a subsample that included a total of 4366 subjects with both baseline and exit FBG and vitamin B12 measurements. Adjusted for age, sex, MTHFR gene C677T polymorphisms, SBP and DBP at baseline, mean SBP and DBP during the treatment period, body mass index, study center, baseline serum concentrations of folate, homocysteine, FBG, vitamin B12, total cholesterol, triglycerides, and high-density lipoprotein cholesterol, treatment group, smoking status, and alcohol consumption status. DBP, diastolic blood pressure FBG, fasting blood glucose MTHFR, methylenetetrahydrofolate reductase SBP, systolic blood pressure.

How Much B12 Should I Take Vitamin B12 Supplements

How much B12 should I take? Or even: Do I really need to take B12 supplements?

Vitamin B12 supplements are really important for vegans, for anyone with digestive issues and for older adults.

Vitamin B12 is a pretty difficult vitamin for our digestive systems to break apart from food and absorb. For people who have less-than-perfect digestion, supplements are often a good thing to take.

As we age, our digestive system becomes less effective, so older adults are prone to B12 deficiency. Interestingly, B12 deficiency symptoms are similar to senility and dementia, so it might be passed off as just part of the aging process.

If you think you might be low, you can check yourself for vitamin B12 deficiency symptoms and its a good idea to have your urine or blood tested for an objective and quantitative look.

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Should I Be Worried If My B12 Is High

Though daily high doses of B12 are unlikely to cause harm in most people, extremely high doses should be avoided unless prescribed by a healthcare professional. 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.

Who Might Be At Risk Of A Vitamin B12 Deficiency

VITAMIN B12 | Deficiency, Supplements, Foods and Daily Recommendation

Anyone who is unable to eat a varied and balanced diet or whose digestion is compromised, including the elderly, may be more at risk of B12 deficiency. Additionally, people with certain medical conditions, such as coeliac disease and Crohns disease, may be unable to absorb adequate B12 from food.

Strict vegans who do not include any fish, poultry, eggs or dairy products in their diet and are not taking vitamin B12 supplements are at increased risk of deficiency. For those eating an exclusively plant-based diet, it is recommended to get B12 levels checked regularly. Vegetarians who do not regularly include dairy in their diet and do not include fortified foods such as plant-based milks and spreads may also be at risk and should see their GP if they are concerned.

Furthermore, women who are pregnant or breastfeeding should consult their GP for guidance if they are concerned that they may be deficient in vitamin B12.

Anyone considering taking a B12 supplement should talk to their GP or associated health professional first.

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Vitamin B12 And Vegan Diets

B12 is an exceptional vitamin. It is required in smaller amounts than any other known vitamin. Ten micrograms of B12 spread over a day appears to supply as much as the body can use. In the absence of any apparent dietary supply, deficiency symptoms usually take five years or more to develop in adults, though some people experience problems within a year. A very small number of individuals with no obvious reliable source appear to avoid clinical deficiency symptoms for twenty years or more. B12 is the only vitamin that is not recognised as being reliably supplied from a varied wholefood, plant-based diet with plenty of fruit and vegetables, together with exposure to sun. Many herbivorous mammals, including cattle and sheep, absorb B12 produced by bacteria in their own digestive system. B12 is found to some extent in soil and plants. These observations have led some vegans to suggest that B12 was an issue requiring no special attention, or even an elaborate hoax. Others have proposed specific foods, including spirulina, nori, tempeh, and barley grass, as suitable non-animal sources of B12. Such claims have not stood the test of time.

How Much B12 Should You Take

For healthy individuals who are not at risk for B12 deficiency, eating a well-rounded, healthy diet should provide all the B12 their body needs.

Food sources of this vitamin include eggs, red meat, poultry, seafood, milk, yogurt, fortified cereals, nutritional yeast and fortified non-dairy milks.

However, individuals on medications that impact B12 absorption, pregnant or breastfeeding women, vegans and anyone with a condition that negatively impacts the absorption of or increases the need for B12, should consider taking a supplement.

Additionally, evidence from population studies suggests that B12 deficiency in older adults is common, which is why its recommended that adults over 50 take supplements .

While megadoses of up to 2,000 mcg are considered safe in treating B12 deficiency, its always best to avoid excessive amounts of any vitamin, especially when its not needed.

Though daily high doses of B12 are unlikely to cause harm in most people, extremely high doses should be avoided unless prescribed by a healthcare professional.

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 bodys ability to absorb the vitamin depends on how much it actually needs.

For example, its estimated that only 10 mcg of a 500-mcg B12 supplement is actually absorbed in people without a deficiency (

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Signs Of Deficiency And Toxicity


Measuring vitamin B12 in the blood is actually not the best way to determine whether someone is deficient, as some people with a deficiency can show normal B12 blood levels. Blood levels of methylmalonic acid, a protein breakdown product, and homocysteine are better markers that capture actual vitamin B12 activity. These values increase with a vitamin B12 deficiency. It is estimated that up to 15% of the general population has a vitamin B12 deficiency.

Factors that may cause vitamin B12 deficiency:

Signs of deficiency may include:

  • Megaloblastic anemiaa condition of larger than normal sized red blood cells and a smaller than normal amount this occurs because there is not enough vitamin B12 in the diet or poor absorption
  • Pernicious anemiaa type of megaloblastic anemia caused by a lack of intrinsic factor so that vitamin B12 is not absorbed
  • Fatigue, weakness


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