Iron absorption in your body can be slowed down due to the consumption of dairy, tea, coffee, raw vegetables, whole grains, calcium, phytates and bran foods. Consuming these foods with iron is not good for your health and can result in iron deficiency.
Avoiding coffee is better after having iron in either a meal or through supplements. Even after one hour of consuming iron, drinking a cup of coffee has the same inhibition in iron absorption as simultaneous consumption. So avoid having coffee for at least two hours after taking iron tablets or iron-rich meals.