What is the role of iron deficiency in hair loss and how is it treated?

From the Guidelines

Iron deficiency is likely associated with hair loss, particularly in female patients, and treatment with oral iron supplements can help improve hair growth. When considering the role of iron in hair loss, it is essential to understand that iron serves as a cofactor for ribonucleotide reductase, the rate-limiting enzyme in DNA synthesis, which is crucial for tissues with high cellular turnover like the hair follicle matrix 1. The primary indicator of iron status in hair loss studies is serum ferritin, which reflects a patient’s total iron storage 1. Some studies have found lower ferritin levels in patients with alopecia areata (AA), telogen effluvium (TE), androgenetic alopecia (AGA), and diffuse hair loss, suggesting a potential link between iron deficiency and hair loss 1. However, other studies have found no association between iron deficiency and hair loss, highlighting the need for further research to fully understand the relationship between iron and hair loss 1. In terms of treatment, oral iron supplements such as ferrous sulfate, ferrous gluconate, or ferrous fumarate can help improve hair growth by increasing iron levels and reducing shedding and thinning hair. Key points to consider when treating iron deficiency-related hair loss include:

• Treatment duration usually lasts 3-6 months, continuing until ferritin levels reach at least 50-70 ng/mL
• Dietary changes are also important, incorporating iron-rich foods like lean red meat, spinach, lentils, and fortified cereals
• Common side effects of supplementation include constipation, nausea, and black stools, which can be managed by adjusting dosage or formulation
• Severe iron deficiency may require investigation for underlying causes such as heavy menstrual bleeding, gastrointestinal blood loss, or malabsorption disorders. It is crucial to note that the current evidence is not conclusive, and more research is needed to fully understand the relationship between iron and hair loss 1.

From the Research

Iron Deficiency and Hair Loss

• Iron deficiency is a common nutritional deficiency that can cause various health problems, including hair loss 2, 3.
• The relationship between iron deficiency and hair loss is complex, and studies have produced conflicting results 2, 4, 5.
• Some studies suggest that iron deficiency may be related to certain types of hair loss, such as alopecia areata, androgenetic alopecia, telogen effluvium, and diffuse hair loss 2, 6.
• However, other studies have found no clear association between low serum ferritin and chronic diffuse telogen hair loss 5.

Diagnosis and Treatment

• Serum ferritin concentration is commonly used to diagnose iron deficiency, but it may be elevated in patients with infectious, inflammatory, and neoplastic conditions 2.
• Hemoglobin concentration can be used to screen for iron deficiency, but it may not be sufficient to confirm the diagnosis 2.
• Treatment of iron deficiency anemia includes adequate dietary intake and oral iron supplementation, but excessive iron supplementation can cause iron overload 2, 3.
• The decision to screen for iron deficiency or provide iron supplementation therapy in patients with hair loss should be based on clinical judgment 2.

Iron Deficiency-Related Alopecia

• Iron deficiency-related alopecia is a common cause of hair loss in women, accounting for 70% of cases in one study 6.
• The study suggested that iron supplementation can improve hair regrowth and increase ferritin levels, but the disease duration is an important prognostic factor for improvement 6.
• The corresponding ferritin level for female anemia was found to be lower than the adequate level for hair growth, highlighting the importance of early diagnosis and treatment 6.