Let’s say I’m vegan and I need to take vitamin B12 supplements to be healthy. Furthermore, let’s say I have ADHD, I forgot to take them for a month, I feel like shit, and while I know to take them now, there’s no guarantee I’ll remember tomorrow.
If I were to take 2 tablets today, an amount which I surely need, would my body actually absorb all the B12 it needs, or would I piss out the second tablet? Do I have to wait until tomorrow to absorb the nutrients my body needs now?
Does that mean I actually only need one tablet a week or a month? My doctor said I should have one every day.
No. The body can only absorb a certain amount at a time. Do what your doctor said.
AFAIK you can’t overdose b12, but in any case I’d follow a doctor’s advice