Vitamin C and Hair Loss
Vitamin C supplementation does not have proven efficacy for treating hair loss, and current evidence does not support its routine use for this indication. 1, 2
Evidence for Vitamin C in Hair Loss
Biological Role
- Vitamin C functions as a water-soluble antioxidant and serves as a cofactor for collagen biosynthesis, which theoretically could support hair follicle structure 1
- The vitamin plays roles in cellular turnover and oxidative stress reduction, processes relevant to rapidly dividing hair follicle cells 1, 2
Clinical Evidence
- No direct evidence exists demonstrating that vitamin C supplementation improves hair loss in adults with or without deficiency 2, 3
- A controlled trial examining vitamin C supplementation (500-1000 mg daily for 3 months) found no significant effects on hair mineral content, suggesting limited biological impact on hair health 4
- The ESPEN guidelines mention vitamin C only in the context of improving iron absorption when taken concurrently with iron supplements, not as a primary treatment for hair loss 1
What Actually Works for Hair Loss
Proven Nutritional Deficiencies
Vitamin D deficiency shows the strongest association with hair loss, with 70% of alopecia areata patients deficient versus 25% of controls, and lower levels correlate inversely with disease severity 5, 6
Iron deficiency (ferritin <70 μg/L) is associated with chronic diffuse telogen hair loss and should be corrected when present 1, 5
Zinc deficiency shows lower serum levels in alopecia areata patients, particularly those with resistant disease >6 months duration 5, 6
Clinical Recommendations
- Screen for vitamin D, iron (ferritin), and zinc in patients with hair loss and risk factors for deficiency 5, 2
- Supplement only documented deficiencies—there is no evidence that supplementation benefits those with normal baseline levels 3, 7
- For vitamin C specifically, the recommended daily intake is 75 mg for women and 90 mg for men, easily achieved through diet 1
Critical Pitfalls to Avoid
- Do not recommend vitamin C supplementation for hair loss in the absence of scurvy or documented deficiency 2, 3
- Excessive vitamin supplementation may paradoxically worsen hair loss or cause toxicity 3, 8
- Focus on proven interventions: vitamin D supplementation for deficiency (<20 ng/mL), iron repletion when ferritin is low, and evidence-based treatments like intralesional corticosteroids for alopecia areata 5, 6
When Vitamin C May Be Indicated
The only evidence-based use of vitamin C in hair loss management is as an adjunct to iron supplementation to enhance iron absorption in patients with documented iron deficiency 1