Answer:
iron deficiency is one of the most common nutrient deficiencies across the life span". Mangieri says .If you're not getting enough," Iron" ,you run the risk of not being able to focus or concentrate." the easiest sources of iron is fortified cereal, Mangieri says - aim for 3/4 cup daily. teen boys should aim for 8 to 11 mg of iron each day; females need 15 mg per day and up to 18 mg once they reach age 18 onward.