Determination and Evaluation of Bioavailability of Vitamins from Different Multivitamin Supplements Using a Pig Model

This study was performed to evaluate the plasma vitamin kinetic behavior following oral vitamin supplement administration in pigs, and to determine the bioavailability of vitamins. A total of 36 pigs (fitted with jugular catheters) with an average body weight of 25 ± 2.24 kg were divided into three treatment groups: (1) placebo, (2) non-microencapsulated multivitamins supplement, or (3) lipid matrix microencapsulated multivitamins supplement. The blood samples were obtained starting pre-meal until 72 h post-meal for plasma vitamin analysis. Pharmacokinetic parameters were modeled with a non-compartmental method. The AUC (Area under the curve) from the time of dosing to the time of the last observation, C max (Maximum observed concentration), and MRT (Mean residence time) of α-tocopherol from oral non-microencapsulated supplement were significantly lower than oral microencapsulated supplement ( p < 0.01). The average relative bioavailability of vitamin A (VA) and vitamin E (VE) from microencapsulated supplement was greater than that from non-microencapsulated supplement, but relative bioavailability of vitamin K 3 (VK 3 ) and water-soluble vitamins from microencapsulated supplement was lower than non-microencapsulated supplement. The AUC and C max of menadione, thiamine, and riboflavin from microencapsulated supplement were significantly lower than these parameters from oral non-microencapsulated supplement. Lipid matrix microencapsulation was able to delay absorption and improved the bioavailability of VE, whereas there were limited effects of microencapsulation on vitamin D (VD), VK 3 , and water-soluble vitamins.