Are there legitimate medical reasons for the treatments that Clemens claims?

The only people who legitimately might need vitamin B12 injections would be those with confirmed diagnoses of pernicious anemia, said Dr. George Blackburn, director of the Center for the Study of Nutrition Medicine at Beth Israel Deaconess Medical Center. “And it’s virtually impossible” to get pernicious anemia in modern America, where there is ample access to fish, eggs, and dairy products.