About Vitamin B12

• Vitamin B12 is a water-soluble vitamin that helps build and maintain red blood cells and nerve cells. It is also required to create DNA. B12 is created during digestion and combines with a substance called "intrinsic factor" before it is absorbed into the bloodstream. Foods like shellfish, meat and dairy products are high in Vitamin B12. It is not difficult to maintain adequate amounts through a normal diet.
  
  

Primary Side Effects

• The side effects of taking B12 supplements are not life-threatening, but they may be unpleasant. The most common side effects are mild diarrhea, breathing problems, hives, skin rashes, insomnia, anxiety, panic attacks, breathing problems and heart palpitations. Symptoms often disappear within a few days but, in rare cases, can recur for several months. Research also shows that side effects are more common when B12 is administered through an injection.
  
  

Rare Side Effects

• Patients taking Vitamin B12 supplements should check their medical history to make sure there is no family history of Leber's Disease, a hereditary eye condition that causes the optic nerve to atrophy. Research has shown that large doses of B12 can cause an early onset of the disease and lead to more rapid degeneration of the optic nerve.
  
  

Why Some Must Take B-12

• Since most people get plenty of Vitamin B12 through the foods they eat, most people don't need to take supplements. People who need B12 tend to be elderly or suffer from an intestinal or digestive problem that renders them unable to absorb B12 through the foods they eat. Vegetarians are also at risk since they usually don't eat foods that contain adequate amounts of B12.
  
  

Few Problems

• Though Vitamin B12 can produce unwanted side effects, they tend to be mild. And even if a person suffers some side effects from B12 supplements, the benefits of taking them typically outweigh what is usually just temporary discomfort.