Bioavailable Source of Iron Non-Constipating NOW Iron Complex is a unique blend of Ferrochel Iron (a bioavailable form of iron) and its important co-nutrients combined with complementary botanicals. Iron is a mineral required for the formation of hemoglobin, a molecule that transports oxygen to the cells throughout the body in red blood cells. Vitamin B-12 and Folate are necessary for red blood cell production, while Vitamin C is known to enhance Iron absorption from the GI tract. This vegetarian formula is well-tolerated and non-constipating and has been designed to maximize Iron absorption and utilization by the body.