E.BhatnagarD.CottyP
Risk factors that should prompt consideration of B12 deficiency include advancing age (reduced stomach acid production), strict vegan or vegetarian diets, pernicious anaemia, gastrointestinal surgery (particularly gastric bypass or ileal resection), long-term use of certain medications (metformin, proton pump inhibitors, H2-receptor antagonists), nitrous oxide exposure (including recreational use), and conditions affecting the gut such as Crohn's disease or coeliac disease
Some people at a certain age, say age 70, would have aged more quickly, typically if you have bad genes, you smoke, you dont exercise, you become obese at an early age, thats what will happen to you, and vice versa
Modular coronas further improve tissue selectivity