This essential vitamin is generally considered safe, even at high doses. However, most people get enough B12 through diet alone, and unnecessary supplementing may lead to negative side effects.
Vitamin B12 is a water-soluble nutrient that plays many critical roles in your body.
Some people think that taking high doses of B12 — rather than the recommended intake — is best for their health. This practice has led many to wonder how much of this vitamin is too much.
Learn more about the health benefits, as well as the potential risks of taking megadoses of B12.
There’s no question that vitamin B12 is essential for health. It’s responsible for
- red blood cell formation
- energy production
- DNA formation
- development and function of the central nervous system
Though B12 is found in many foods, some people don’t get enough of this important vitamin.
Current evidence
Although B12 supplements are commonly taken to boost energy levels, there is currently no evidence suggesting that more B12 increases energy in people with adequate levels of this vitamin.
However, B12 supplements will most likely increase energy levels in those who are deficient, as this nutrient plays an important role in converting food into energy.
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
This threshold has not been set for B12 because your body excretes whatever it doesn’t use through your urine.
However, B12 in an injectable form may cause some negative side effects, such as:
For healthy individuals who are not at risk for B12 deficiency, eating a well-rounded, nutrient-rich diet should provide all the B12 their body needs.
Food sources of this vitamin include
- eggs
- red meat
- poultry
- seafood
- milk
- yogurt
- fortified cereals
However, individuals taking medications that affect B12 absorption and people who are pregnant or nursing should consider talking with a doctor before taking a supplement.
While megadoses of up to 2,000 mcg are considered safe in treating B12 deficiency, it’s always best to avoid excessive amounts of any vitamin, especially when it’s not needed.
If you think you may be deficient in B12, consider speaking with a doctor. They can recommend an appropriate treatment based on your level of deficiency.
B12 is an important nutrient that is often 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.
Most people can fulfill their B12 needs through a nutrient-rich diet. However, some people, including those who are pregnant, should consider talking with a doctor about supplementation.
