I am wondering how does the level of B12 in the blood (veins) looks like over the time, starting oral intake. There are few forms of B12 and I am interested in the ones that are melting well in the month (e.g. methylcobalamin, adenosylcobalamin). To be more specific on the question/answer, if that helps, I am providing the exact values of each - 1mg of B12 (500µg methylcobalamin and 500µg adenosylcobalamin).
Now, let's say I put that 1mg in the month. It starts to melt there. When will the peak happen in the blood stream (veins)?
Someone says it should be "fast", but this isn't about the time therefore not acceptable.
I did some sort of research on it and came with the following.
After oral administration of a drug, absorption into the bloodstream occurs in the stomach and intestine, which usually takes about one to six hours. https://www.britannica.com/science/drug-chemical-agent/Absorption
This suggests B12 absorption will be faster than 1 hour because it does not need to reach the stomach.
The same article later states the following:
To pass from the bloodstream to the target site, drug molecules must cross the walls of blood capillaries. This occurs rapidly in most regions of the body. The capillary walls of the brain and spinal cord, however, are relatively impermeable, and in general only drugs that are highly lipid-soluble enter the brain in any appreciable concentration.
I assume the same "rapidly" will apply to the direction month -> bloodstream. However, even if I am right, the "rapidly" looks the same as "fast" to me here. Therefore not really acceptable too. So I tend to think it will be up to 1 hour. I would like to say the peak of the B12 in the veins will be in about 15 minutes after the intake. However, I am lacking the data to back this guess up at this point. Do someone have the better answer here?