What vitamins and supplements can help a patient with hair loss, particularly those with potential androgenetic alopecia?

Vitamins and Supplements for Hair Loss

Primary Recommendation for Vitamin Screening

For any patient with hair loss, particularly those with suspected androgenetic alopecia, check serum 25-hydroxyvitamin D, serum zinc, and RBC folate levels; in women, also check serum ferritin. 1

Vitamin D: The Strongest Evidence

• Vitamin D deficiency shows the most robust association with hair loss, with 70-83% of alopecia areata patients demonstrating deficiency (<20 ng/mL) compared to only 23-33% of controls 1, 2
• Lower vitamin D levels correlate inversely with disease severity, and the vitamin D receptor (VDR) plays a critical role in hair follicle cycling during the anagen (growth) phase 2
• Supplement vitamin D in all patients with levels <20 ng/mL according to standard adult dosing recommendations, though no double-blind trials have yet examined oral supplementation specifically for alopecia treatment 1, 2
• Consider topical calcipotriol 0.005% twice daily for patchy alopecia areata in vitamin D-deficient patients, as 59-75% achieve hair regrowth, with greatest improvement in those with lowest baseline levels 2

Zinc: Second-Line Screening Priority

• Serum zinc levels tend to be lower in alopecia areata patients, particularly those with resistant disease lasting >6 months 1, 3
• In patients with serum zinc below 70 μg/dL, consider 50 mg zinc gluconate daily, which led to therapeutic improvement in 60% of patients at 12 weeks in one small study 1
• However, the only double-blind placebo-controlled trial using 220 mg zinc sulfate twice daily for 3 months showed no improvement despite increased serum zinc levels, highlighting the need for caution 1

Folate: Check RBC Levels, Not Serum

• Check RBC folate rather than serum folate for accurate assessment of long-term folate stores, as RBC folate levels are lower in alopecia areata patients and correlate negatively with disease severity 1
• Folate as a methyl-group donor contributes to nucleic acid production in the highly-proliferative hair follicle 4

Iron: Gender-Specific Screening

• Check serum ferritin only in women with hair loss, as evidence for iron deficiency is conflicting and gender-dependent 1, 3
• Lower ferritin levels are found primarily in female patients with alopecia areata and androgenetic alopecia, but not consistently in males 4, 1
• Iron deficiency remains the most common nutritional deficiency worldwide and is a sign of chronic diffuse telogen hair loss 4, 3
• Current evidence is insufficient to recommend routine iron screening in all alopecia patients or in men specifically 4, 1

Vitamin B12: Do Not Routinely Screen

• Do not check vitamin B12 levels unless pernicious anemia is suspected clinically, as multiple case-control studies found no differences in B12 levels between alopecia areata patients and controls 1

Critical Caveats and Pitfalls

• Most evidence comes from small retrospective case-control studies, limiting generalizability, and reverse causation is possible where hair loss may lead to lifestyle changes affecting micronutrient levels 1
• Serum micronutrient levels may not accurately reflect tissue bioavailability 1
• Many studies use combination therapies making it difficult to definitively attribute efficacy to individual supplement components 1
• Few randomized controlled trials exist for micronutrient supplementation in alopecia treatment 1

Proven Medical Treatments Beyond Vitamins

For androgenetic alopecia specifically, FDA-approved treatments (topical minoxidil 5% for men, oral finasteride 1 mg) have far stronger evidence than any vitamin supplementation 5, 6:

• Topical minoxidil 5% is FDA-approved for men with vertex hair loss, with results visible at 2-4 months of twice-daily use 5
• Oral finasteride 1 mg and dutasteride 0.5 mg are effective 5-alpha reductase inhibitors, with dutasteride inducing better responses especially in the frontal area 7
• Low-level laser light therapy (630-660 nm wavelengths) is FDA-cleared and superior to placebo 6

Practical Clinical Algorithm

1. First, determine the type of hair loss through history, examination, and dermoscopy (looking for yellow dots and exclamation mark hairs in alopecia areata) 3
2. For all hair loss patients: Check serum 25-hydroxyvitamin D, serum zinc, and RBC folate 1
3. For women only: Add serum ferritin 1
4. Supplement deficiencies identified: Vitamin D if <20 ng/mL, zinc if <70 μg/dL (though evidence is weaker) 1, 2
5. For androgenetic alopecia: Prioritize FDA-approved treatments (minoxidil, finasteride) over vitamin supplementation alone 5, 6
6. Do not delay proven treatments while waiting to correct vitamin deficiencies, as the evidence for vitamins is primarily associative rather than causative 4, 1