An average brand may contain about 25 mcg, which is more than 400% of the recommended daily value. Check with your doctor to determine if multivitamins is right for you. There is little risk from taking too much B12, however, high amounts may interact with certain medications.
What is the recommended daily intake of vitamin B12?
Vitamin B12 Dosage: How Much Should You Take per Day?
- Suggested dosages. The recommended daily intake (RDI) for vitamin B12 for people over 14 is 2.4 mcg ( 1 ). ...
- Potential side effects. Vitamin B12 is a water-soluble vitamin, meaning that your body excretes what you don’t need in your urine.
- The bottom line. Vitamin B12 is a nutrient that plays many essential roles in your body. ...
Does B12 actually make you more energetic?
Vitamin B-12 has a big role in stabilizing your energy levels. It actually helps give you more energy, rather than making you tired. If you do notice feeling a little fatigued, even though you’re...
What is the Max dose for B12?
In essence, high dose B12 is useful in treating a deficiency. For healthy people, a B12 dosage of between 250 – 500 µg will safely cover the daily requirement. It should be noted that this information refers to oral supplements – the dosage of vitamin B12 injections is discussed in a separate article.
Which vitamin B should I take?
Vitamin B complex supplements usually contain the following:
- B1 (thiamine). Thiamine plays an essential role in metabolism by helping convert nutrients into energy. ...
- B2 (riboflavin). Riboflavin helps convert food into energy and also acts as an antioxidant. ...
- B3 (niacin). ...
- B5 (pantothenic acid). ...
- B6 (pyridoxine). ...
- B7 (biotin). ...
- B9 (folate). ...
- B12 (cobalamin). ...
Is 25 mcg of B12 a lot?
ADULTS: BY MOUTH: The typical general supplemental dose of vitamin B12 is 1-25 mcg per day: The recommended dietary allowances (RDAs) of vitamin B12 are: 1.8 mcg; older children and adults, 2.4 mcg; pregnant women, 2.6 mcg; and breast-feeding women, 2.8 mcg.
How much vitamin B12 should I take daily MCG?
The recommended daily intake (RDI) of vitamin B12 is 6 micrograms per day. Deficiency is common, especially in people who follow a vegetarian or vegan diet. In fact, it's thought that up to 90% of people following these diets have a deficiency ( 2 , 3 ). This is because B12 is only found naturally in animal foods.
Is 24 mcg of B12 enough?
The recommended daily intake (RDI) for vitamin B12 for people over 14 is 2.4 mcg ( 1 ).
Is 50 mcg B12 enough?
The usual dose for: diet-related deficiency is 50 micrograms to 150 micrograms, taken once a day. B12 deficiency not caused by your diet is one to two 1,000 microgram tablets, taken once or twice a day – this is usually if you cannot have vitamin B12 injections.
What happens if your B12 is too 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.
What does MCG mean in vitamin B12?
microgramsUnlike some vitamins, vitamin B12 is measured in micrograms, not milligrams. A microgram is a thousandth of a milligram, so 500 mg of vitamin B12 is 500,000 micrograms. The recommended daily intake is between 2 and 2.8 micrograms. However, you can safely go well beyond that number.
Is 1000ug B12 too much?
There is no risk of an overdose when taking large amounts of vitamin B-12 such as 1000 mcg, because it is a water-soluble vitamin. Meaning the body will use the amount that it needs then the excess will be excreted through urine.
How much B12 should an older woman take?
Recommended Vitamin B12 Dosage for Seniors A recent study found that for seniors, a daily dose of 500 micrograms was efficient in reversing the signs of B12 deficiency. In general, experts recommend 2.5 micrograms of vitamin B12 per day for people over the age of 14.
What is the lowest mcg for vitamin B12?
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. High doses of vitamin B-12, such as those used to treat a deficiency, might cause: Headache.
How long should I wait to eat after taking B12?
That's why the best time to take vitamin B12 is right when you get up in the morning. It's also a good time to drink a glass of water, since you're likely a bit dehydrated. Doctors typically recommend taking it at least 30 minutes before your meal to give it time to absorb.
Is it OK to take 1000 mcg of B12 a day?
Taking B12 supplements can be an effective way to treat B12 deficiencies and isn't necessarily inferior to B12 shots. If you're deficient, your doc may recommend you take about 1,000 to 2,000 mcg of vitamin B12.
Is 5000 mcg vitamin B12 safe?
Is 5000 mcg of B12 too much? A dosage of 5000 mcg of Vitamin B12 has been deemed a safe dosing amount. In fact, it is often recommended for those who have a health condition that affects their B12 absorption.
Is 2000 mcg of B12 okay?
The bottom line. B12 is an important nutrient that is popularly used as a nutritional supplement, even by those without a B12 deficiency. Though doses of up to 2,000 mcg of vitamin B12 are considered safe, it's best to speak with a doctor to find out whether taking a supplement is necessary.
Is 2500 mcg of B12 okay?
The recommended dose for treating vitamin B12 deficiency is 1000 mcg daily. The recommended dose for preventing vitamin B12 deficiency is 1500 mg or 2500 mcg (sublingual tablets) daily.
What are the signs of a B12 deficiency in infants?
In infants, signs of a vitamin B12 deficiency include failure to thrive, delays in reaching the typical developmental milestones, and megaloblastic anemia.
How long does it take for a vitamin B12 deficiency to show?
Your body stores 1,000 to 2,000 times as much vitamin B12 as you’d typically eat in a day, so the symptoms of vitamin B12 deficiency can take several years to appear.
What are the symptoms of vitamin B12 deficiency?
Vitamin B12 deficiency causes tiredness, weakness, constipation, loss of appetite, weight loss, and megaloblastic anemia. Nerve problems, such as numbness and tingling in the hands and feet, can also occur. Other symptoms of vitamin B12 deficiency include problems with balance, depression, confusion, dementia, poor memory, ...
How to tell if you have a B12 deficiency?
In infants, signs of a vitamin B12 deficiency include failure to thrive, problems with movement, delays in reaching the typical developmental milestones, and megaloblastic anemia. Large amounts of folic acid can hide a vitamin B12 deficiency by correcting megaloblastic anemia, a hallmark of vitamin B12 deficiency.
What is the best vitamin for a weak body?
Vitamin B12 is a nutrient that helps keep your body’s blood and nerve cells healthy and helps make DNA, the genetic material in all of your cells. Vitamin B12 also helps prevent megaloblastic anemia, a blood condition that makes people tired and weak.
How does the body absorb vitamin B12?
Two steps are required for the body to absorb vitamin B12 from food. First, hydrochloric acid in the stomach separates vitamin B12 from the protein to which vitamin B12 is attached in food. After this, vitamin B12 combines with a protein made by the stomach called intrinsic factor and is absorbed by the body. ...
How much B12 is safe?
The amount of vitamin B12 in supplements varies widely. Some provide doses of vitamin B12 that are much higher than recommended amounts, such as 500 mcg or 1,000 mcg, but your body absorbs only a small percentage of it. These doses are considered safe. Check the Supplement Facts label to see how much vitamin B12 a supplement contains.
How much B12 is in a multivitamin?
Multivitamin/mineral supplements typically contain vitamin B12 at doses ranging from 5 to 25 mcg [ 22 ]. Vitamin B12 levels are higher, generally 50–500 mcg, in supplements containing vitamin B12 with other B-complex vitamins and even higher, typically 500–1,000 mcg, in supplements containing only vitamin B12.
What is B12 parenteral?
Parenteral administration is typically used to treat vitamin B12 deficiency caused by pernicious anemia as well as other conditions (e.g., tropical sprue, pancreatic insufficiency) that result in vitamin B12 malabsorption and severe vitamin B12 deficiency [ 5 ].
How much B12 is in breast milk?
The average vitamin B12 level in the breast milk of women with vitamin B12 intakes above the RDA is 0.44 mcg/L [ 14 ]. The U.S. Food and Drug Administration specifies that infant formulas sold in the United States must provide at least 0.15 mcg vitamin B12 per 100 kcal [ 15 ].
What is the most common form of vitamin B12?
The most common form of vitamin B12 in dietary supplements is cyanocobalamin [ 1, 3, 22, 23 ]. Other forms of vitamin B12 in supplements are adenosylcobalamin, methylcobalamin, and hydroxycobalamin [ 22 ]. No evidence indicates that absorption rates of vitamin B12 in supplements vary by form of the vitamin.
How to determine vitamin B12 levels?
Vitamin B12 status is typically assessed by measurements of serum or plasma vitamin B12 levels . The cutoff between normal vitamin B12 levels and deficiency varies by method and laboratory, but most laboratories define subnormal serum or plasma values as those lower than 200 or 250 pg/mL (148 or 185 pmol/L) [ 2 ]. Levels of serum methylmalonic acid (MMA), a vitamin B12-associated metabolite, are the most sensitive markers of vitamin B12 status, and an MMA level greater than 0.271 micromol/L suggests vitamin B12 deficiency [ 6-8 ]. However, MMA levels also rise with renal insufficiency and tend to be higher in older adults [ 6, 9, 10 ]. Another marker is total plasma homocysteine levels, which rise quickly as vitamin B12 status declines; a serum homocysteine level higher than 15 micromol/L, for example, suggests vitamin B12 deficiency [ 11 ]. However, this indicator has poor specificity because it is influenced by other factors, such as low folate levels and, especially, by declines in kidney function [ 6 ]. Experts suggest that if a patient’s serum vitamin B12 level is less than 150 pg/ml (111 pmol/L), the patient’s serum MMA levels should be checked to confirm a diagnosis of vitamin B12 deficiency [ 7, 9 ].
How is vitamin B12 released?
Vitamin B12 is bound to protein in food and must be released before it is absorbed [ 5 ]. The process starts in the mouth when food is mixed with saliva. The freed vitamin B12 then binds with haptocorrin, a cobalamin-binding protein in the saliva. More vitamin B12 is released from its food matrix by the activity of hydrochloric acid and gastric protease in the stomach, where it then binds to haptocorrin [ 1 ]. In the duodenum, digestive enzymes free the vitamin B12 from haptocorrin, and this freed vitamin B12 combines with intrinsic factor, a transport and delivery binding protein secreted by the stomach’s parietal cells. The resulting complex is absorbed in the distal ileum by receptor-mediated endocytosis [ 1, 5 ]. If vitamin B12 is added to fortified foods and dietary supplements, it is already in free form and therefore does not require the separation step.
What is B12 used for?
Vitamin B12 functions as a cofactor for two enzymes, methionine synthase and L-methylmalonyl-CoA mutase [ 1-3, 5 ] . Methionine synthase catalyzes the conversion of homocysteine to the essential amino acid methionine [ 1, 2 ].
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.
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#).
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 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.
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 if your UMMA is high?
However, if your uMMA levels are high, you probably have a B12 deficiency.
Why is MMA high in the urine?
That’s because the kidneys excrete the MMA in the urine. If they don’t function correctly, MMA may accumulate in your blood. Serum MMA levels may also be high in patients with thyroid disease or bacterial overgrowth in the small intestine.
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.
How accurate is the UMMA test?
Therefore, uMMA tests can predict one’s path toward permanent neurological impairments. The test has a whopping 99% accuracy, making it confirmatory. Keep in mind, if you have kidney disease you may get false high levels with the serum MMA test, or false low levels with the uMMA test.
How does B12 work?
How B12 works in the body. The Harvard Medical School Special Health Report Making Sense of Vitamins and Minerals explains that vitamin B12, like all B vitamins, is water soluble, which means the body expels what it does not use. Its main job is to maintain healthy nerve cells, support proper brain function, and assist in the production ...
Why do vegans have trouble consuming enough B12?
Vegans and vegetarians sometimes have trouble consuming enough B12 since many food sources are found in animal products like meat and dairy. Low levels of B12 can cause fatigue, nervousness, dizziness, numbness, and tingling in the fingers and toes.
Why do older people have a low B12 level?
This is often due to a poor diet and less stomach acid, which the body needs to absorb B12 from food.
What is the role of B12 in the body?
Its main job is to maintain healthy nerve cells, support proper brain function, and assist in the production of DNA and RNA. B12 also works with other B vitamins to improve certain functions. For instance, B12 and B9 (folate) together help to make red blood cells.
How old do you have to be to take a multivitamin?
In fact, the federal government's Dietary Guidelines for Americans suggest that people older than age 50 take a multivitamin supplement as a way to ensure adequate B12 intake. Many store multivitamins contain high amounts of B12.
Can B12 be corrected?
Severe, long-term deficiency may lead to loss of mobility, problems walking, or memory loss. A blood test from your doctor can measure B12 levels. A serious deficiency can be corrected with B12 shots or high-dose supplements.
Does Harvard Health Publishing have archived content?
As a service to our readers, Harvard Health Publishing provides access to our library of archived content. Please note the date of last review or update on all articles. No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.
What is the cause of anemia?
A deficiency of vitamin B12 can contribute to your developing a type of anemia called megaloblastic or pernicious anemia. Because vitamin B12 is used in the production of red blood cells and the maintenance of the nervous system, a deficiency can cause your body to manufacture inadequate red blood cells.
What is B12 found in?
Found primarily in animal products such as fish, poultry, eggs, milk and other dairy products, B12 is also used to enrich some grain products. Advertisement. According to the University of Florida, adults who are not pregnant or breastfeeding require 2.4 micrograms of B12 a day, while pregnant women should get 2.6 micrograms ...
How much B12 is 500 mg?
Unlike some vitamins, vitamin B12 is measured in micrograms, not milligrams. A microgram is a thousandth of a milligram, so 500 mg of vitamin B12 is 500,000 micrograms. The recommended daily intake is between 2 and 2.8 micrograms. However, you can safely go well beyond that number.
What is the purpose of B12?
B12 also helps to keep levels of some amino acids stable and to prevent damage to your nerve cells. Found primarily in animal products such as fish, poultry, eggs, milk and other dairy products, B12 is also used to enrich some grain ...
Can you take B12 if you don't take it?
If you aren't taking a B12 supplement, toxicity isn't an issue. Since B12 is a water-soluble vitamin, it won't build up in your body. There are some situations in which you should not take supplements or high doses of vitamin B12.
Is too much vitamin bad for you?
Image Credit: bong hyunjung/iStock/GettyImages. Normally you have to worry about getting enough vitamins and minerals in your diet to stay healthy. On the other hand, consuming too much of a vitamin can be just as harmful. You're at less risk of consuming too much of water-soluble vitamins like B12 than fat-soluble.
Does pernicious anemia have symptoms?
Advertisement. Pernicious anemia may have no symptoms and occurs most frequently in people who suffer either from an autoimmune disorder or who have a disease of malabsorption that prevents their bodies from absorbing enough vitamin B12.
