Answer: The good news is that tea is steeped in health benefits. The bad news is that tea contains compounds called tannins that can bind to iron in the body and inhibit absorption.
Drinking tea at meals has been shown to reduce iron absorption far more than drinking coffee. This is especially true when it comes to the absorption of nonheme iron (derived from plant sources), which is much more influenced by the tannins in tea than heme iron (derived from animal sources).
You can counteract the negative effect of tannins in tea by taking two simple steps. Be sure to eat foods that boost iron absorption (e.g., vitamin C–rich foods, meat, fish and poultry) at every meal. You should also try to avoid drinking tea during meals and instead consume this particular beverage between meals.
These tips are especially important for clients who have poor iron status and those who are more at risk for iron deficiencies, such as teenage girls and women of childbearing age.