The phrase "to increase the bioavailability" means to enhance the amount or rate at which a substance can be absorbed and used by the body. Full definition
So don't pass up the salad at the BBQ and be sure to add some healthy fats, which increase the bioavailability of a number of the goodies found in dark leafy greens. (bodyunburdened.com)
I add a dash to my morning bone broth, along with some freshly ground black pepper, which increases its bioavailability by 2,000 percent. (mindbodygreen.com)