I don't know why but I find everything related to B-12 and Folate to be incredibly complex to wrap my brain around b/c there are so many nuances and intricacies.
Honestly, the "why" isn't horribly important with B12 deficiency, since the solution is always injecting B12.
I have never injected myself with a needle, and am just not sure I can do it, even though the muscle strength in my arms has greatly improved.
If an inactive form is used, large doses can be injected into the muscle by a doctor or nurse periodically. It might even be as infrequently as once a month or less, since the human body does a pretty good job of storing B12. I self-inject twice a week, and it's really low on the exertion scale. It's also something that a family member could very easily learn to do.
