They are found in the soil and streambeds. They form rocks and even meteors. If you saw them in a lab, you’d think they had nothing to do with what is on your dinner plate. However, minerals such as zinc, iron, magnesium and sulfur all serve critical functions in the human body, and you can get your allotment in a healthy, balanced diet or by taking supplements for specific deficiencies.
The body absorbs the bulk of its nutrients through the intestinal wall during digestion. The rate of absorption depends upon a number of factors including your overall diet, the presence of other minerals in the meal and whether or not you are getting enough vitamins. Sometimes, your body determines whether or not a mineral is absorbed for use. If you are iron-deficient, for example, you will absorb iron from your diet at a higher rate than someone who is not.
The rate of absorption is called “bioavailability,” and it’s a measure of how much of each mineral your body is able to process. Some minerals compete against each other for your body’s digestive resources. For example, large amounts of zinc in your diet will lower the absorption rate of iron and copper. Other minerals work together. Calcium, phosphorus and magnesium combine to give rigidity to your teeth and bones.
Plants and their derivatives are rich in minerals, but they are sometimes bound in forms that make them unavailable. Phytates, or the salts of phytic acids, are present in many plants, and they can block absorption of some key nutrients, particularly for vegetarians. Minerals from animal sources, such as calcium from dairy and iron from red meat, are not bound by phylates and so are said to be more bioavailable than plant-based minerals.
Although some minerals compete with each other for your body’s attention, vitamins are the helpful stewards ushering necessary nutrients into the bloodstream. Vitamin deficiencies can lower the bioavailability of some minerals. For example, vitamin C helps your body absorb iron efficiently while vitamin D aids in calcium, phosphorous and magnesium digestion. Milk is often fortified with vitamin D for this reason.