Taking vitamin B12 as a form of supplement poses no risk. That is, if they are taken according to their proper doses. There are general recommendations for the daily doses of vitamin B12 for health maintenance. If the vitamin is taken in excessive amounts, you are liable to experience adverse side effects. However, these side effects will expire soon as the excess amounts of vitamin B12 is flushed out of your body. Even then, it is important for you to know about vitamin B12 side effects so that you will be more careful when taking your daily dose.

But it is people who get B12 via injection that are most likely to get side effects. But some of them are also true for those who are taking other forms of vitamin B12, including sublingual vitamin b12. There are two types of vitamin B12 side effects – mild side effects and severe side effects. For mild side effects, you will experience swelling and pain on the skin where the vitamin is injected. You may also feel nauseous, accompanied with vomiting sensations. Other side effects may include mild to severe headaches, skin rashes, mild diarrhea and mild joint pains.

But it’s the severe side effects that you need to be most careful with. You may suffer heart palpitation causing you to lose your breath. Feeling numbness all over your body is another. Other serious side effects may include difficulty in swallowing, getting tired easily even with light work, urinating frequently especially at night, muscle pains in the legs, muscle cramps, tight chest sensation and sudden weight gain.

There are also psychological side effects that you need to be aware of. Taking excess amounts of vitamin B12 may cause you to have panic attacks and anxiety. You just have to control your nerves when this happens, because this will disappear in a few hours, after the excess B12 is flushed out of your system.

If you have a history of Leber’s disease, then there is a rare side effect that you need to be aware of. For these people they need to consult their doctor before taking B12. Leber’s disease is a hereditary condition that causes the atrophy of the optic nerve. Large doses of vitamin B12 for such persons may result in the onset of this disease, or it may cause the rapid deterioration of their optic nerve.

People who are allergic to cobalt and cobalamin should also avoid taking B12 supplements. They should endeavor to get their daily requirements of B12 from natural foods such as beef liver, fish, oysters, yogurt, milk, etc.