One of the 13 key vitamins that our bodies require to function correctly is vitamin B12. As a result, we frequently encounter it.
It is advertised as a benefit on morning cereal boxes, available as a nutritional supplement on drugstore shelves, and even mentioned on the labels of your favorite beverages.
Others take it when blood tests reveal low amounts of the vitamin, and many individuals take it to increase their energy.
The right amount to consume of vitamin B12 as a dietary supplement might be tricky to figure out. There are numerous product categories and many of them have various doses. Can you ever take too much, then?
What Exactly Is B12?
Your body requires vitamin B12 as a nutrient to support wellness. It participates in DNA synthesis and supports your nerves, red blood cells, and other body tissues.
But your body is unable to produce vitamin B12 on its own. Animal derived food or meals fortified with vitamin B12 are the only sources of vitamin B12.
Most folks find this to be sufficient. Others, however, might need to take prescription drugs or vitamin B12 supplements as prescribed by their doctor.
How Does Your Body Absorb Vitamin B12?
Your body absorbs vitamin B12 in two processes from the food you eat:
- Vitamin B12 is detached from the dietary protein it is bound to by your stomach acid.
- Your body binds vitamin B12 to a stomach-produced protein known as intrinsic factor. The body may absorb vitamin B12 after it is bound to intrinsic factor, allowing it to begin functioning. Supplements omit this initial phase, but in order to be absorbed, they still need intrinsic factor.
Some individuals simply don’t get enough vitamin B12 when it comes to food.
People who consume a minimal amount of animal products on a vegan or vegetarian diet may experience this. Oral B12 supplements (such as solutions and tablets) can help in these circumstances.
However, some individuals’ systems have issues absorbing vitamin B12. They may not be able to produce intrinsic factor or they may have intestinal inflammation as possible explanations for this.
Alternative formulations, such as injections, nasal sprays, or tablets that dissolve beneath the tongue, may be required in certain circumstances. These different compositions avoid your digestive system.
Benefits of Vitamin B12 Supplements
The importance of vitamin B12 for health cannot be overly emphasized.
Numerous bodily processes, including the creation of energy, red blood cells, DNA, and neuron upkeep, depend on vitamin B12.
Despite the fact that foods including meat, poultry, seafood, eggs, dairy products, and fortified cereals contain the essential vitamin B12, many people still do not get enough of it.
Age, genetic variations, dietary restrictions, and medical diseases including inflammatory bowel disease (IBD) can all increase the demand for vitamin B12.
Those at risk should speak with their doctor about taking a high-quality B12 supplement, as vitamin B12 deficiency can result in serious problems such as; nerve damage, anemia and exhaustion.
According to the most recent research, persons who eat enough B12-rich foods and are able to utilize it efficiently may not need to take supplements.
In patients without advanced neurological problems, for instance, a meta-analysis from 2021 discovered that vitamin B12 administration is probably useless for enhancing cognitive function and depressive symptoms.
Although B12 supplements are frequently taken to promote energy, there is presently no proof that taking additional B12 makes persons with adequate levels of this vitamin feel more energetic.
B12 supplements, however, will probably result in a rise in energy levels in those who are deficient because this nutrient is crucial for turning food into energy.
Is There Any Right Dosage For Vitamin B12?
There is no B-12 maximum limit listed by the Office of Dietary Supplements (ODS). This is so because vitamin B-12 is typically well tolerated by humans with no negative side effects.
According to a study published in the journal American Family Physician, researchers have shown that dietary supplements containing up to 1,000 times the RDA are safe.
Vitamin B-12 is not effectively absorbed by the body. In reality, according to research, only 9.7 micrograms (mcg), or 2%, of a 500 mcg dose are absorbed by the body.
The ODS states that the RDA for vitamin B-12 varies with age as follows:
- 0 – 6 months: 0.4 mcg
- 7 – 12 months: 0.5 mcg
- Ages 1-3 years: 0.9 mcg
- Ages 4 to 8 year: 1.2 mcg
- Ages 9 to 13 years: 1.8 mcg
However, those who are taking medications that interfere with the absorption of B12, those who are pregnant or nursing, vegans, and those who have medical conditions that interfere with the absorption of or increase the need for B12 should think about speaking with their doctor about taking a supplement.
Additionally, data from population studies suggest that older folks frequently experience B12 insufficiency, which is why it’s advised that those over 50 think about taking supplements.
Megadoses of up to 2,000 mcg are thought to be safe for treating B12 insufficiency, but it’s always advisable to avoid taking too much of any vitamin, especially when it’s not required.
Even though most people are unlikely to be affected by daily high doses of B12, extremely high doses should be avoided unless a medical practitioner recommends them.
Speak with your doctor if you suspect you could be B12 deficient so they can assess your level of insufficiency and propose the best course of action.
High Dosage Of B12 Beneficial Or Harmful?
B12 is a water-soluble vitamin, thus even high doses are typically regarded as safe.
Due to B12’s low degree of toxicity, there is no Tolerable Upper Intake Level (UL). The term “UL” stands for the highest daily dose of a vitamin that is unlikely to have any negative side effects on the majority of people.
Because your body excretes any excess B12 through your urine, this threshold has not been established for B12.
B12 supplements are necessary for those who have a greater requirement for this vitamin, but they are not necessary for those who do not have a deficiency.
However, using overly high doses of B12 as a supplement has been associated with some unfavorable side effects.
Can Someone Have Excessive Blood Levels of Vitamin B-12?
There is no established upper limit for the amount of vitamin B-12 in the blood. The excess vitamin B-12 that a person consumes from diet or supplements will normally be excreted by the body.
Supplemental vitamin B-12 is not particularly well absorbed by the body. This indicates that a person’s body does not absorb much vitamin B-12, regardless of how much they consume.
Additionally, some drugs may make it more difficult for the body to absorb vitamin B-12. These drugs include, as examples:
- Metformin
- Proton pump inhibitors
- A type of antibiotic called chloramphenicol (Chloromycetin)
Possible Symptoms Of High Doses Of B12
Even at high quantities, vitamin B12 poses no danger. As a result, there isn’t yet a recommended maximum dose.
However, at typical levels, several forms of vitamin B12—primarily injectable and nasal B12—can result in a headache or weariness.
By dose form, side effects change. However, uncommon side effects at standard doses typically include:
- Nausea
- Diarrhea
- Common cold symptoms,
- Itchy skin
- Clogged nose
Conclusion
B12 is a crucial component that is frequently used as a dietary supplement even for those who do not have a B12 deficiency.
Although vitamin B12 doses up to 2,000 mcg are thought to be safe, it’s advisable to consult a doctor to determine whether taking a supplement is necessary.
Majority of people can get all the B12 they need by eating a nutrient-rich diet.
However, some people should think about discussing supplements with their doctor, especially older persons and those with specific dietary limitations.
References
Kubala, Jillian. “How Much Vitamin B12 Is Too Much?” Healthline, Healthline Media, 15 Feb. 2022, https://www.healthline.com/nutrition/too-much-vitamin-b12#dosage.
“Vitamin B-12: How Much Is Too Much?” Medical News Today, MediLexicon International, https://www.medicalnewstoday.com/articles/326187#low-vitamin-b-12-levels.
