Vitamin B12 overdose: Side effects of taking too many supplements; know when to stop
How much Vitamin B12 is too much?
Vitamins and minerals play a significant role in maintaining our overall health. Eating nutrient-dense foods therefore not only takes care of our physical health but also tends to our mental well-being.
Vitamin B12 is one of the most essential nutrients to add to your diet. While it is not naturally produced, it is present in many foods including animal produce and seafood and can also be received through supplements.
The primary role of this vitamin is to support the nervous system and to make red blood cells. Given that vitamin B12 is water-soluble, it is easily absorbed in the intestines, following which it facilitates the production of DNA. Besides that, it also helps enhance energy and boost metabolism.
When should you resort to Vitamin B12 supplements?
Vitamin B12 deficiency is a common occurrence among people and because it helps serve several bodily functions, many resort to supplements. Since the body does not produce it naturally and one may miss out on the foods that possess this essential nutrient, supplements seem to be the best available alternative.
However, experts recommend getting your vitamin B12 from food, before trying a supplement. If you're someone who has eliminated meat, dairy and fortified cereals from your diet, then it is possible that you may require supplements. However, it is best to talk to your dietician or physician.
Mostly, vitamin B12 is advised to be taken in the morning or with a meal, since it is associated with energy metabolism, which may interrupt your sleep if taken at night. Experts recommend taking B12 supplements with a glass full of water to optimize absorption.
Can you overdose on B12?
While overdosing on vitamin B12 is said to be highly unlikely, experts believe it is possible to have elevated B12 levels.
That said, although side effects from vitamin B12 supplementation are very rare, it can possibly occur with B12 injections, but not with oral supplements. Vitamin B12 injections are said to be effective at increasing blood levels of B12, preventing or reversing deficiency of the same.
It is important to note however that the shots must be prescribed by a doctor and given intramuscularly. These usually contain hydroxocobalamin or cyanocobalamin. The rate of absorption for these injections are believed to be higher than oral supplementation, which is why experts warn against possible side effects.
Side effects to note
Taking oral supplementation is safe if taken at recommended doses. However, B12 shots can lead to side effects including:
- Headache
Dizziness
- Diarrhea
- Skin rash and itching
- Nausea and vomiting
- Fatigue
- Swelling and tingling sensation
Additionally, excess vitamin B12 can also result in rare but severe allergic reactions also known as anaphylaxis. This could lead to face, tongue and throat swelling.
Here's what you need to know about the right dosage
The National Institutes of Health of Dietary Supplements recommends the following dosage of vitamin B12 for different groups of people.
- 2.4 micrograms (mcg) daily for ages 14 years or older
- 2.6 mcg daily for pregnant women
- 2.8 mcg daily for breastfeeding women
For those over 50 years of age, the recommended dietary amount (RDA) is 25 to 100 mcg of B-12 or one can get it by eating vitamin B12-rich foods.