Comment · Wed, July 15, 2015 · Ceretropic
"You do not need to take fat with fat soluble vitamins"
Original post in this thread
theskepticalidealist · 25 points
I wanted to have people comment on this thread but it's been archived and now you can't.
So, fact or fiction? Some people said fiction so wanted a discussion to make it clearer to people.
What they were answering
shydominantdave · 3 points
Is the fat myth true for other substances besides vitamins? My pharmaceutical says it requires a meal with fat for absorption (Viibryd).
Bioavailability 72% (Oral, with food)
u/MisterYouAreSoDumb · Ceretropic
Remember, my point was that a substance being fat soluble does not automatically mean you need fat to absorb it. Many substances suggest taking food with them to slow your GI tract motility, or to prevent upsetting your stomach. Vilazodone looks like it needs longer to absorb in your GI tract. So taking it with fat or food will signal your body to slow down the GI tract motility, allowing longer for it to be absorbed. The fat itself is not facilitating the absorption, though. It is just signaling your body to slow down the movement through the GI tract, which then allows things to absorb in higher amounts.
Take Aniracetam for example. It is high lipophilic. However, it is rapidly and completely absorbed in the GI tract from a fasting state. If fat-soluble drugs needed fat to absorb, then that would not be the case. Your intestines are lined with a mucous membrane, which is a lipid membrane that facilitates the absorption of molecules. The membrane itself is the fat, which lipophilic molecules rapidly pass through. Also, just because a drug is hydrophobic does not mean it will automatically be lipophilic. It's more complicated than that.