Bio-availability?
Bioavailability refers to the amount a nutrient is actually absorbed and used by the body. Certain compounds in foods may diminish or enhance the bioavailability of different minerals in the gut. The phytates and oxalates of leafy vegetables hinder both iron and calcium absorption, while vitamin C and vitamin D enhance it.
Dietary lipids are considered to be a key factor for carotenoid bio-availability. However, most carotenoid-rich fruits and vegetables are low in lipids. A study concluded that the addition of avocado fruit as a lipid source enhances carotenoid absorption from salad and salsa in humans.
Interactions between minerals impacts their bioavailability. Zinc inhibits the absorption of copper. Physiological factors determine also how far the body can re-use, store and compartmentalize micro-nutrients.
Compounds common in foods, like carbonates, oxalates, phosphates, and phytates, attach themselves often to inorganic minerals to form insoluble precipitates, thus preventing absorption of minerals in the small intestine.
Since minerals are excreted in our feces and urine, we must replenish them through diet and supplements. Mineral supplements are available in inorganic mineral salts and mineral chelates.
