Some foods can block the absorption of vitamins. For example, calcium can hinder the absorption of iron, so it's best not to take them together. Additionally, high fiber foods, such as bran, can interfere with the absorption of minerals like zinc and calcium. However, consuming prebiotic foods like legumes, oats, and potatoes, as well as healthy fats and complementary proteins, can actually enhance nutrient absorption. Managing stress, taking probiotics, and chewing thoroughly can also improve absorption.