Point to Ponder

Here's an interesting tid-bit:

RNY patients don't absorb 25% of their intake.

Makes me really motivated to make sure I hit my numbers daily.

25% of what part of their intake?  25% of their intake of calories?  Protein?  Vitamin A?  Vitamin B12?

And at what point post op are we talking about?

Malabsorbtion is a problem right after he procedure. 25% of food intake, and seeing as we have to take vitamins forever, those too.

So you're saying right after surgery, we do not absorb 25% of the calories we eat?  I'm curious about where that number came from.  It was my understanding that since everyone is a bit different, it was pretty much impossible to say exactly how much we would or would not absorb.

Also, malabsorption of macronutrients like calories, fat and protein decreases over time.  So we might not absorb 25% of things right after surgery but we would be absorbing a lot more by one year post op.

I understand we malabsorb vitamins forever.  It's the middle of the night here and I'm not good at math even when I'm not tired.  But if we absorb 75% of the vitamins we take, why do we need to take 200% of the RDA of most things?  Wouldn't that mean we only needed 125% or 150% instead?  I can't figure out which one, it's too late for that much math.

Also, with vitamin D for instance, there are three spots in the small intestine that absorb vitamin D.   But two of those get bypassed with RNY.  So wouldn't that suggest that we would only absorb about 33% of the D we take, not 75%?