Coffee, Phytates and Tannins can decrease the absorption of which mineral?

• A. Copper
• B. Zinc
• C. Magnesium
• D. Iron

Answer: (D)

The effect being tested is how certain dietary inhibitors reduce iron absorption. Coffee, phytates, and tannins bind non-heme iron in the digestive tract, forming complexes that are not easily dissolved or absorbed by the intestinal lining. Phytates, found in whole grains, seeds, and legumes, chelate minerals including iron, while tannins in coffee and tea similarly bind iron during digestion. This effect is most notable for iron from plant sources (non-heme iron); iron from animal sources (heme iron) is less affected. To improve absorption, consuming vitamin C-rich foods with iron-containing meals can help solubilize non-heme iron, and separating coffee or tea from iron-rich meals can reduce the inhibitory impact. Phytates can also reduce absorption of other minerals like zinc, but iron is the mineral most commonly reduced by these substances in typical diets.