Herbs such as pepper increase the bioavailability of vitamin D, etc
Science Shows Herbs Can Significantly Enhance Bioavailability of Nutrients GreenMed Info Sept 2014
Pepper - (does not indicate how much increase)
Vitamins (water soluable)
Vitamin B1, Vitamin E2, Niacinamide, Vitamin B6, Vitamin B12, Folic acid, Vitamin C
Vitamins (fat soluable)
Vitamin A, B-Carotene (provitamin), Vitamin D , Vitamin E, Vitamin K
Amino Acids
Lysine, Isoleucine, Leucine, Threonine, Valine, Tryptophan, Phenylalanine. Methionine
Minerals
Iodine, Calcium, Iron, Zinc, Copper, Selenium, Magnesium , Potassium, Manganese
Does show quantitative bioavailability increases by other herbs - but not to Vitamin D
Does have detailed references - exampli is attached at the bottom of this page