Bioavailability of Minerals in FoodsFoods from both plants and animals are sources of minerals. Generally speaking, animals tissue contains minerals in the proportions that the animals needs, so animal-derived foods are more reliable mineral sources.
Plant foods can be excellent sources of several minerals, but the mineral content of plants can vary dramatically depending on the minerals and the soil where the plants are found.
Even the maturity of a vegetable, fruit or grain can influence its mineral content. Because actual mineral content varies too much, the values published in food composition tables can be misleading.
Often this value are omitted. Like plant foods, drinking water has variable mineral content, Nevertheless, it sometimes, can be a significant source of minerals such as sodium, magnesium and fluoride.
Your gastrointestinal tract absorbs a much smaller proportion of minerals than vitamins - and probably for good reason.
Once absorbed, excess minerals often are difficult for the body to flush out. In many cases, the body adjusts mineral absorption in relation to needs. For example, a calcium deficient person absorbs calcium more readily than does a person with normal calcium status.
Mega-dosing with single mineral supplements can hamper the absorption of other minerals. Minerals such as calcium, iron, zinc and magnesium , for example, all have similar chemical properties and compete for absorption.
Fiber and other components of food also affect mineral bioavailability. High fiber diets reduce absorption of iron, calcium, zinc, and magnesium.
Phytate (a component of whole grains) binds minerals and carries them our of the intestine unabsorbed.
Oxalate (found in spinach and rhubarb) binds calcium, markedly reducing calcium absorption.
Bioavailability of Minerals in Foods
