Vitamin B-12 is typically prescribed for people diagnosed with pernicious anemia who need monthly injections of the nutrient. The National Institutes of Health report that little more than one percent of the population in the United States lives with the disorder. Alcoholics and individuals adhering to a strict vegetarian or vegan diet along with people suffering from Celiac or Chron's disease may also be vitamin-B12 deficient. However, in recent years, the vitamin received notoriety and has been promoted as an instant energy boost or as a weight loss aid. Now, the vitamin is offered in juice bars, medical spas and weight loss clinics. Nevertheless, there are potential downsides to taking vitamin B-12.
Possible Side Effects
Following an injection, individuals may experience pain, redness and swelling at the injection site. Some may suffer from itching, diarrhea and feeling an overall swelling of the body. Other possible adverse reactions include:
• Abdominal cramping
• Difficulty breathing when lying or during exercise
• Generalized muscle weakness
• Increased heart rate
• Arm and leg swelling
• Redness, warmth, swelling and discomfort in one leg from blood clot formation
Allergic Reactions or Unusual Side Effects
Some individuals may take vitamin B-12 and not be aware that they have a condition known as polycythemia vera, which involves the overproduction of red blood cells. In this instance, people may experience difficulty breathing, itching and reddening of the face. Though rare, allergies to the cobalt or cobalamin in vitamin B-12 may occur. The symptoms of an allergic reaction include itching, reddening and swelling of the face, a swollen tongue and possibly swelling the in throat. Victims also suffer from dizziness and difficulty breathing.
Vitamin B-12 is responsible for normal red blood cell formation, proper nerve function and DNA synthesis along with contributing to the creation of RNA, hormones, lipids and proteins in the body. Adults require between 2.6 and 2.8 micrograms of the water soluble vitamin daily. Sufficient quantities of the nutrient are commonly obtained by eating all types of meat, poultry and fish in addition to dairy products and fortified cereals. Unnecessarily taking additional supplements in oral or injectable forms could result in an overdose.
Symptoms of excessive vitamin B-12 include itching anywhere on the body, numbness and tingling of the extremities, irregular or rapid heart rate. Some suffer routine headaches, elation and giddiness. Extensive abuse of the vitamin occurring over a long time period may increase the risk of developing cancer as the compound stimulates cell division. Even patients needing routine injections stand a chance of developing leukemia. Individuals getting the vitamin by regularly consuming a large quantity of animal products may develop esophageal or stomach cancer.