Complex sentence: Iron deficiency leads to iron-deficiency anemia which occurs when there is lower levels of hemoglobin in the blood than required-it is related to blood loss as hemoglobin is lessened because hemoglobin requires iron to transport oxygen through the blood.
Split into simpler sentences: Iron deficiency leads to iron-deficiency anemia which occurs when there is lower levels of hemoglobin in the blood than required. It can be related to blood loss, because hemoglobin requires iron to transport oxygen through the blood.