Natural Factors Iron Factors - 35 mg - With B12 & Folic Acid for optimal absorption and bio-availability. Iron is found in abundance in the blood, and is essential for good health. Iron is necessary for the production of hemoglobin (red blood corpuscles), myoglobin (red pigment in muscles), and certain enzymes. Iron deficiency is common and may be caused by poor diet, prolonged use of antacids, excessive consumption of coffee or tea, prolonged menstrual bleeding, internal bleeding and heavy perspiration due to prolonged excessive exercise. Symptoms of iron deficiency include anemia, brittle hair or hair loss, dizziness, fatigue, nervousness, obesity and slowed mental reactions. Iron supplementation can help restore and maintain proper iron levels in the body.