Many people dont absorb B12 as well when taken orally
Often people with chronic diseases that affect the gut (such as Celiac disease or Crohns disease) become deficient too
(4) Ghulam Murtaza, Abida Kalsoom Khan, Rehana Rashid, Saiqa Muneer, et al (2017) FOXO Transcriptional Factors and Long-Term Living Oxidative Medicine & Cellular Longevity, 2017, Volume 2017, Page 3494289
For some parts of the day, I no longer need to wear eyeglasses anymore at all
GI issues can make certain options hard to tolerate
Health Benefits Researchers are actively studying the impact of B12 on cancer risk, cardiovascular disease, energy, endurance, cognitive function, and dementia