Dear Dr. SerVaas,
I was diagnosed with pernicious anemia in 1982 and prescribed 1000-microgram shots of B12 (cyanocobalamin) every month for the rest of my life. I have since moved, and my current doctor advises that 100 micrograms a month is sufficient, a dose I have been taking for more than two years. I have many health problems and am wondering if a lack of B12 could be causing them.
There is study data to support both doses. To confirm the best amount for you, we suggest that you consider asking your doctor to order a complete blood count (CBC) to examine the number, size, and shape of your blood cells.
The term “pernicious” or “fatal” anemia dates back to the time before scientists discovered that it is a vitamin deficiency disorder. Characteristic signs and symptoms of the condition include feeling tired and weak, tingling and numbness in hands and feet, and a bright red, smooth tongue. Your cardiovascular health problems seem to have started before switching to the lower dose of cyanocobalamin.