Iron deficiency can manifest as weakness, fatigue, shortness of breath on exertion, dizziness, tinnitus, spots before the eyes, drowsiness, irritability, infrequent menses, and loss of libido. Individuals who have a greater need for iron, or who tend to chronically lose iron, or who don't absorb iron well, can benefit from a formula that can increase the amount of hemoglobin in the blood, such as Ferrasorb®. Studies indicate that combining iron with essential B vitamins and vitamin C is superior to using these nutrients individually.

Thorne® Ferrasorb combines the active forms of vitamin B6 (pyridoxal 5'-phosphate), vitamin B12 (methylcobalamin), and folate (L-5-methyltetrahydrofolate) with well-absorbed iron bisglycinate – for an optimal blood-building supplement. Vitamin C is added to enhance iron's absorption.

Individuals who are susceptible to being deficient in iron include teenage girls, pregnant women, women of childbearing age (particularly if they have heavy menses), individuals with malabsorption syndromes (Crohn's disease or Celiac disease), individuals on chemotherapy, elderly patients with low stomach acid secretion, and individuals with poor kidney function.