For most people considering taking vitamin B12 injections, side effects are generally not serious. However, in certain instances serious side effects may occur.
Physicians give Vitamin B12 injections, also known as cobalamin or cyanocobalamin injections, to patients that are suffering from anemia, fatigue or other symptoms of vitamin B12 deficiency. Patients that have pernicious anemia require lifelong vitamin B12 injections and may want to consider dietary changes for B12 deficiency. These injections are sometimes very painful as they are given deep under the skin, known as a deep subcutaneous injection, or into a muscle, called an intramuscular injection.
Common Side Effects of Injections of Vitamin B12
There are many side effects that patients may experience from injections of vitamin B12. The more common side effects include:
- Mild diarrhea
- Upset stomach
- Nausea
- A feeling of pain and a warm sensation at the site of the injection
- A feeling, or a sense, of being swollen over the entire body
- Headache
- Joint pain
If any of these side effects become severe or troublesome, let your doctor know immediately.
Vitamin B12 Injections: Side Effects That are Uncommon and Serious
Vitamin B12 injections can result in serious side effects. Although this is a relatively rare occurrence, anyone taking vitamin B12 injections should be aware of the possibility. Call your doctor immediately if you experience any of the following side effects.
- A rapid heartbeat
- Chest pain
- Heart palpitations
- A feeling of tightness in the chest
- Rapid weight gain
- Muscle weakness
- Muscle pain
- Muscle cramps
- A feeling of extreme thirst
- Frequent urination
- Leg pain
- A sense of confusion
- Numbness
- Dizziness
- A tingling sensation
- Difficulty breathing
- Difficulty swallowing
- Shortness of breath with mild exertion or when lying down
- Unusual coughing
- Unusual wheezing
- A feeling of extreme tiredness or fatigue
- Swelling of the extremities including hands, arms, lower legs, feet or ankles
- Redness, pain or a feeling of warmth in one leg
- Tenderness or swelling in one leg
- A red skin color on the face
- A red skin color anywhere on the body
- Hives
- Itching
- Skin rash
Other vitamin B12 injections side effects may also occur. If you experience anything unusual while taking B12 injections let your doctor know as soon as possible.
July 16th, 2010
It has been often remarked that predicting the future is fraught with error, and that it is much easier to predict the past. Nevertheless, I believe certain tendencies in the field of vaccine development are likely to flourish in the near- and long-term future, and so I venture to make the following 10 predictions:
* The development of combined vaccines containing multiple valences will increase. Valence is the number of different antigens in a vaccine-a trivalent vaccine has three antigens, for example. An antigen is a chemical substance, usually a protein that stimulates the immune system to produce an antibody specific to the antigen. As the schedule for early childhood vaccination becomes more crowded with new vaccines, and as we deal with disease syndromes having multiple causes, it will be necessary to combine vaccines so that fewer injections are given. These combinations of vaccines will not be simple to develop, as the immunologic rules of interference among vaccines are not well described.
* Although many vaccines are administered to infants under the age of one year, protection is slow to develop because of the immaturity of the immune system. In fact, immunity may fade later in childhood if no booster doses are given. The specific factors that contribute to the immaturity are just becoming known, and I anticipate that immunologic adjuvants-substances that enhance responses to vaccination-will come into use in infancy. Sexually transmitted diseases, respiratory diseases transmitted by crowding, infections that cause cancer later in life, and infections transmitted from mothers to their fetuses all require vaccination before adolescence begins. Thus, the age of 11 to 12 years will become a time for administration of many newly emerging vaccines to provide protection during early adult life.
* The elderly suffer a natural aging of the immune system, both with respect to antibody production and cellular responses to infection or vaccination. Here again, we are beginning to understand the defects that come with age, and correction of these defects should improve the efficacy of vaccines in an increasingly aged population.
* Two new strategies have become widespread for experimental vaccine development: injecting humans with DNA segments from pathogenic microorganisms that produce protective proteins after injection, and inserting genes from pathogens into harmless microorganisms that serve as carriers, or vectors, for production of immune responses. Although each strategy separately may generate useful vaccines, the combination of the two in a so-called “prime-boost sequence” provides synergy. Thus, there will be vaccinations consisting of prime-boost regimens, particularly in those cases where antibodies are insufficient to give complete protection.
* Intramuscular or subcutaneous injections have served us well as the means to introduce vaccines into humans. However, there are limitations to the feasibility of numerous injections and theoretical reasons for preferring other routes of immunization. Thus, intranasal, aerosol spraying and oral routes of administration are being intensively explored for certain vaccines. Moreover, transcutaneous immunization using patches, microneedles, and other ingenious technologies to pass vaccines through the skin is promising.
* Malaria, tuberculosis and HIV are major targets of vaccine development. Short-term protection against malaria has already been achieved, and I foresee the extension of protection by combining several malaria antigens in one vaccine, although I suspect that regular boosters will be necessary to maintain protection.
* Prospects for a vaccine that protects against adult tuberculosis are good. This will be based on the current BCG vaccine. The Bacillus Calmette-Guérin vaccine, developed at the Institut Pasteur in Lille, France, in the early 20th century, is effective in children but does not prevent the infection in adults. Insertion of genes that code for additional protective proteins should improve BCG.
* HIV has proven to be a difficult target for vaccination, but a vaccine that reduces the seriousness of infection and prolongs life, even while not preventing the disease completely, is likely to be the product of current clinical trials. The development of a vaccine that prevents infection entirely is less likely in the near future.
* Influenza remains a banal but deadly infection. Although the vaccines we have are very beneficial, better protection will be derived from the inclusion of more influenza proteins, adjuvants, and the combined use of live and killed vaccines.
December 4th, 2008