The problem I have is I have had to take Prilosec for maybe 40 years now. Prilosec can reduce the absorption of vitamin B12 from food, particularly from animal-derived dietary sources that contain protein-bound vitamin B12. Omeprazole (Prilosec) inhibits gastric acid production, which is necessary for the activation of pepsin, an enzyme that cleaves proteins and releases vitamin B12 for absorption. Reduced acid levels also lead to increased gastric pH, which can promote bacterial overgrowth in the gastrointestinal tract; these bacteria can consume vitamin B12 before it is absorbed in the ileum. As a result, long-term use of omeprazole—especially for three years or more—increases the risk of developing vitamin B12 deficiency, which may lead to complications such as macrocytic anemia. I also have been taking Metformin for 10 years as part of my longevity program. It too interferes with B-12 absorption. The only way to solve this is by doing B-12 injections and completely bypassing the digestive system.
I consume about 46..2ug of B-12 in my diet, which is about 1932% over RDA from the 325g of protein I eat on a daily basis. Still my blood levels of B-12 are very low, so I have no choice but to supplement.
Sleep apnea? Did a in clinic study back in 2007 and have been using a CPAP since then. I had OSA.
The B-12 I have is 5000ug/ml.