Iron is one of the most vital minerals for our cells. Iron’s main purpose is to carry oxygen in the hemoglobin of red blood cells throughout your body so your cells can produce energy. Iron is essential for cognitive function, including memory, problem-solving, concentration, and learning. An iron deficiency can manifest as weakness, fatigue, shortness of breath on exertion, dizziness, tinnitus, spots before the eyes, drowsiness, irritability, infrequent menstruation, and loss of libido.