Why we need vitamin B12?

Vitamin B12 or Cobalamin, which belongs to the vitamin B Complex family, is a water-soluble vitamin that's important in the DNA production and in developing healthy nerve and red blood cells. It's absorbed into the bloodstream during digestion. It helps your body use fats and carbohydrates for energy.

What are the sources of vitamin B12?

 Foods such as shellfish, liver (best source), beef/mutton, chicken, pork/ham, fish, whole egg, cheese, yoghurt are good sources of the vitamin B12. Aside from food sources, it can be obtained in supplements, which can be taken orally in pill form, injected intravenously, applied to the mouth and nose in gel form and skin patches.

Can you take too much of vitamin B12?

 Vitamin B12 can be consumed in large doses because excess is excreted by the body or stored in the liver for use when needed. Stores of vitamin B12 can last for up to a year.Its toxicity is very low and mostly occurs in extremely rare genetic disorders. But, taking too much of supplements can cause toxicity because your body will not eliminate it as quickly since supplements have a readily absorbable form of vitamin B12 so it would be better to eat natural foods instead of taking supplements.

What are the side effects of taking too much of vitamin B12?

  • Cardiovascular side effects:

Vitamin B12 injections/patches can cause irregular or rapid heartbeats and palpitations. In severe cases you could experience chest pain, shortness of breath, weakness on one side of the body and other signs of a stroke.

  • Psychological side effects:

You can have negative psychological side effects if you take too much of it. They include panic, anxiety attacks and insomnia. These side effects can lead to breathing problems and heart palpitations created by panic and anxiety.       

  •  Gastrointestinal side effects:

If you take too much vitamin B12, an extremely rare side effect is gastrointestinal problems. Elderly people and people with a history of multiple gastrointestinal surgeries may be especially vulnerable to gastrointestinal problems when taking higher than normal amounts. Symptoms may include nausea, upset stomach, indigestion, vomiting and mild diarrhea.

  • Genetic problems:

If you  have medical history for any occurrence of Leber's disease, a hereditary condition that causes the optic nerve to atrophy, should avoid overdose of vitamin B12 which  can otherwise lead to an early onset of the disease or cause the optic nerve to atrophy more rapidly.

  • Allergic Reactions:

If you are allergic to cobalt and cobalamin then you  may suffer allergic reactions to vitamin B12 supplements. Symptoms of allergic reaction are breathing difficulty, chest pain, and swelling of the tongue, lips and throat. This occurs because the supplements are commonly synthetic formulations of the vitamin, and contain these compounds as part of their chemical structure. If an allergic reaction occurs, you should seek to increase their  intake via dietary sources in which the vitamin occurs naturally.

  •  Dermatological side effects:

 When an  injection is taken, skin may break out in a skin rash or hives. One may also suffer a condition called pruritus, which is characterized by an unpleasant itching sensation that triggers a reflex to scratch. If you take too much vitamin B12, it can cause a rare form of rosacea called Rosacea conglobata. Skin reactions are possible while using vitamin B12 patches. These skin reactions include hives, swelling, rash and itchy skin.

  •  Neonatal side effects:

Benzyl alcohol, a preservative that is contained in the vitamin B12 injection, may cause some serious side effects when given to newborn babies. The newborn may become short of breath and its heart rate may slow down. The baby's blood pressure may also drop. In some cases this preservative can even cause death. The risk of serious side effects increases if the baby had a low birth weight. The  injection is available in a form that does not use this preservative, and should be used for these infants.

  • Other side effects:

While getting injections of vitamin B12, potassium levels may become too low. If this occurs you may experience muscle cramping, weakness, leg pain and numbness.One can also experience weight gain, extreme thirst and frequent urination.

Since vitamin B12 serves many functions throughout the body, it is very essential to maintain adequate store of vitamin B12. To avoid any side effects, recommended daily intake levels of vitamin B12 for infants is 0.4 mcg, children aged 1 to 3 need 0.9 mg, children aged 4 to 8 need 1.2 mcg, and everyone over 14 requires 2.4 mcg  daily.