"Bioavailability" is the ease with which any nutrient can make its way from the food you eat into your body. The bioavailability "journey" that every nutrient takes is the same. In the first part of the journey, the food must be digested (broken apart) so that the nutrient can be freed from the food that contained it. Once the nutrient has been freed from the food that contained it, the second part of the journey involves absorption of the nutrient from the digestive tract into rest of the body.
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