Iron is an important nutrient found in the body. As per World Health Organization iron is one of the top nutrients missing from the diet. Imagine if your body lacks adequate iron what do you think would happen? You just won't have enough oxygen at your disposal. Oxygen is a key factor in everything we do. So without enough oxygen you won't be able to do your daily work properly. Why You need Iron Iron makes hemoglobin which carries oxygen to every cell of the body. Tissues require iron for various biochemical reactions.