According to WebMD, The more common B12 injection side effects are: Swelling at the injection site Mild dirhhea Itching Swelling in the body Low potassium (weakness, irregular heartbeat) There is a case report of an anaphylactic reaction to a B12 injection in a 55 year old women receiving cyanocobalamin, but these reactions are thought to be rare
Manufacturers determine these dates through extensive stability testing, often spanning years, that proves the medication maintains at least 90% potency through the labeled date
Good food sources of vitamin B12 include organic meats, beef, poultry, milk, shellfish, fish, eggs, dairy products, wheat germ, soybeans, fortified cereals, orange juice, oranges, and nutritional yeast
For a subcutaneous B12 injection, a finer, shorter needle is used: around 25 to 27 gauge and half to five-eighths of an inch