B12 deficiency is common and reported to affect 25% of the U.S. population. It strikes up to 15% (5.9 million) older adults > age 64. The CDC reports, one out of every 31 Americans > age 50 are B12 deficient. This report underestimates the incidence by using a cut-off range far too low. The incidence in infants and children is unknown, which is problematic.