Best Naturals Iron 65 mg 240 TabletsIron is essential to nutrition because it is needed to make hemoglobin, the protein that carries oxygen in the blood. The need for iron increases during growth, menstruation, pregnancy, or when there is a loss of blood or a poor diet. Iron is an important component of hemoglobin, the protein that carries oxygen from the lungs to all body tissues and cells. Best Naturals Iron Supplement (Iron Bisglycinate) - 25mg - 180 Tablets - Gentle of Stomach - Non-Constipating.