Vitamins for Hair Loss
For hair loss, prioritize checking and correcting vitamin D deficiency (target >20 ng/mL), iron deficiency (ferritin levels), and zinc deficiency, as these show the strongest evidence for association with hair loss conditions. 1, 2
Primary Micronutrients to Address
Vitamin D (Strongest Evidence)
- Vitamin D deficiency shows the most robust association with hair loss, with 70% of alopecia areata patients having levels <20 ng/mL versus only 25% of controls 2
- Lower vitamin D levels correlate inversely with disease severity in alopecia areata (P < 0.001, r = −0.409) 1
- Vitamin D deficiency is also significantly associated with androgenetic alopecia, with 86% of male patients showing deficiency 3
- Check serum 25(OH)D levels and supplement if <20 ng/mL, though note that no double-blind trials have yet examined oral supplementation specifically for alopecia areata 2
- Topical calcipotriol (vitamin D analog) showed hair regrowth ≥50% in 75% of patients with alopecia areata when applied twice daily for 12 weeks 1
- Combination therapy of oral vitamin D plus topical minoxidil produces better results than either treatment alone in female pattern hair loss 4
Iron (Well-Established Evidence)
- Serum ferritin levels are lower in women with alopecia areata and androgenetic alopecia 2
- Iron deficiency is the most common nutritional deficiency worldwide and a sign of chronic diffuse telogen hair loss 1, 2
- Target ferritin level of 70 μg/L with normal ESR (<10 mm/h) is recommended for patients with increased hair shedding 5
- Iron serves as a cofactor for ribonucleotide reductase, the rate-limiting enzyme in DNA synthesis, critical for rapidly dividing hair follicle cells 1
Zinc (Moderate Evidence)
- Serum zinc levels tend to be lower in patients with alopecia areata, particularly those with resistant disease >6 months duration 2
- Zinc serves as a cofactor for multiple enzymes and plays a role in hair follicle function 2
- However, a 1981 double-blind placebo-controlled trial showed no improvement with 220 mg oral zinc sulfate twice daily for 3 months despite increased serum zinc levels 1
- One 1999 trial combining 100 mg oral zinc aspartate with topical corticosteroid and biotin showed complete regrowth in 33.3% of children versus 0% in controls, but this was combination therapy 1
Additional Micronutrients with Limited Evidence
B Vitamins and L-Lysine
- The essential amino acid L-lysine combined with iron therapy showed benefit in women with increased hair shedding in double-blind data 5
- Biotin (20 mg/day) was used as part of combination therapy in one pediatric trial 1
- Folate deficiency may contribute to hair loss 2
Other Trace Elements (Insufficient Evidence)
- Copper, magnesium, and selenium have theoretical roles but lack sufficient evidence 1
- Most studies found no differences in serum copper or magnesium levels between alopecia patients and controls 1
- Selenium studies yielded conflicting results 1
Clinical Algorithm for Vitamin Assessment
- Check serum 25(OH)D levels first - strongest evidence for association with multiple hair loss types 1, 2
- Measure serum ferritin - particularly important in women with chronic diffuse hair loss 2, 5
- Consider serum zinc levels in patients with resistant alopecia areata >6 months duration 2
- Check TSH to rule out thyroid disease, which commonly coexists with alopecia areata 2
- Consider folate levels if other deficiencies are present 2
Important Caveats
- Excessive vitamin supplementation may actually cause hair loss and is not recommended without proven deficiency 5
- There is no evidence that low serum zinc causes hair loss in the absence of deficiency 5
- Many cases of alopecia areata are self-limited, with 34-50% recovering within one year without treatment 2
- Vitamin D supplementation alone (without minoxidil) showed no significant improvement in Ludwig scale or dermoscopic parameters in female pattern hair loss 4
- The psychological impact of hair loss warrants assessment for anxiety and depression 2