it undergoes first-pass hepatic metabolism, resulting in low (30%–40%) bioavailability.
I'll need to review this later. This is a more precise figure than I was familiar with. I think I read somewhere between 20% and 50%; I believe I cited that figure in one of my college papers.
Here we use piperine, curcumin and resveratrol to formulate the Advanced-PNL formulations.
I'll need to read up on why they used curcumin and resveratrol. I was also planning to use curcumin because it stimulates bile release. That may be their reason as well. They used piperine because it inhibits p450 enzymes. I'm not sure why they might have used resveratrol, though I do recall hearing that it is a bioenhancer.
Each test salad contained 48 g spinach (Spinach; Dole Food Company), 48 g romaine (Hearts of Romaine; Fresh Express), 66 g shredded carrots (Shredded Carrots; Dole Food Company), and 85 g cherry tomatoes
This doesn't sound like adequate protein to stimulate bile. Therefore, this study does not elucidate whether fat is necessary for lipid soluble nutrient absorption. Nevertheless, it does show that fat is sufficient.
The amount of dietary fat consumed with the hot meal (3 or 36 g) did not affect the increases in plasma concentrations of vitamin E (20% increase with the low-fat spread and 23% increase with the high-fat spread) or alpha- and beta-carotene (315% and 139% with the low-fat spread and 226% and 108% with the high-fat spread).
This is some of the better evidence that fat is not necessary for lipid bioavailability. I'm trying to find out if bile alone is sufficient.
A single-dose bioavailability study was performed using three commercially available milks (unfortified whole milk and whole and skimmed milk fortified with vitamins A and E).
They also gave 10 biscuits (full text). This could potentially destroy the entire premise of the study. They estimate that the entire meal contained between 6 and 20 grams of fat, depending on which milk was given. Skimmed milk contains 0.2% fat, so 430ml provides less than a gram. Therefore, the skimmed milk group obtained most fat from the biscuits. Six grams is certainly enough to substantially enable bioavailability.