In most cases, minerals and vitamins in food do not always exist in a chemical form that is suitable for absorption by the body. That's why thousands of chemical processes take place in our cells, which turn the nutrients from different types of food into digestible ones.
What we eat is different from what we digest. Even the healthiest diet has no value for our body if the nutrients cannot be absorbed and transported to the cells that need them. Unlike carbohydrates, fats and proteins, which are efficiently absorbed (85-99% of ingested nutrients are absorbed by the body and enter the bloodstream), some micronutrients are absorbed in extremely small amounts - between 3 and 10% of ingested micronutrients reach blood circulation.
The absorption of most vitamins and minerals depends on their chemical form . For example, iron in food can be in the form of heme iron, which is found only in meat and fish. The other form of iron in food is non-heme iron, which is found in plant foods as well as in iron supplements and medicines. A healthy adult absorbs about 25% of heme iron in food, but only 3 to 5% of non-heme iron.
Moreover, the presence of certain substances in food affects the absorption of minerals . For example, approximately 30 to 45% of the calcium found in milk and dairy products is effectively absorbed by the body, but calcium from spinach, seeds and nuts is absorbed to a much lesser extent because the other nutrients in them block absorption. mu. Non-heme iron, zinc, vitamin E and vitamin B6 are other micronutrients whose absorption from food is greatly reduced due to the presence of other factors.
The absorption of many vitamins and minerals is affected by the intake of other foods. For example, fat-soluble vitamins are absorbed much better when we eat foods high in fat. The absorption of calcium is favored by the presence of lactose, which is contained in milk, and the absorption of non-heme iron can be increased by eating foods rich in vitamin C.