Vitamin D deficiency is increasingly recognised as a contributing factor to hair loss. While it does not cause the same patterned loss as androgenetic alopecia, low vitamin D levels can worsen shedding and impair follicle function — making it an important factor to check and correct.
How Vitamin D Affects Hair Follicles
Vitamin D receptors are present in hair follicle cells. Research has shown that vitamin D plays a role in the creation of new hair follicles and in regulating the hair cycle — specifically in stimulating follicle cycling from the resting phase back into the growth phase.
Studies have found significantly lower vitamin D levels in patients with alopecia areata compared to controls, and lower levels in patients with androgenetic alopecia compared to unaffected individuals. The relationship is correlational — it doesn't prove causation — but correcting deficiency is a low-risk, high-potential intervention.
What Levels Are Considered Deficient?
Laboratory reference ranges vary, but:
- Deficiency: below 20 ng/mL (50 nmol/L)
- Insufficiency: 20–30 ng/mL (50–75 nmol/L)
- Optimal: above 40–60 ng/mL (100–150 nmol/L) for hair health benefits
Many people in Northern Europe and other regions with limited sun exposure are chronically insufficient — not technically deficient by clinical standards, but below optimal for hair function.
Who Is Most at Risk?
- People in Northern Europe and Northern climates with limited sun exposure
- Indoor workers with minimal outdoor time
- People with darker skin (lower vitamin D synthesis from sunlight)
- Vegetarians and vegans (lower dietary vitamin D)
- Patients with conditions affecting vitamin D absorption
Testing and Supplementation
A simple blood test (25-hydroxyvitamin D) measures vitamin D status. If deficient or insufficient, supplementation (typically 1,000–4,000 IU vitamin D3 daily) corrects levels over 3–6 months.
Correcting vitamin D deficiency alone is unlikely to restore significant hair loss that was already established, but it may reduce ongoing shedding and improve follicle health as part of a broader treatment approach.
Vitamin D and Hair Transplant
Patients planning a hair transplant should ideally have vitamin D levels checked and corrected beforehand. Adequate vitamin D levels support graft healing and the overall scalp tissue health needed for optimal transplant outcomes.
Experiencing hair shedding and wondering if nutritional deficiencies are contributing? Our team recommends pre-transplant nutritional assessment as a standard part of our consultation process.