Vitamin D And Hair Loss London. What The Evidence Shows
Low vitamin D is common in the UK, especially from October to March, and studies consistently find lower levels in people with several types of hair loss, most clearly alopecia areata. What the research has not yet shown is that taking vitamin D regrows hair on its own. The practical answer is to test, correct a deficiency if you have one, and treat the hair loss itself alongside it, because vitamin D is rarely the only cause.
Key points
In the UK, government advice is that everyone should consider taking 10 micrograms of vitamin D a day during autumn and winter, when sunlight is too weak for the skin to make enough.
A 2020 meta-analysis of 19 studies with 1,585 people with alopecia areata found they were about 4 times more likely to be vitamin D deficient than people without hair loss.
Lower vitamin D has also been reported in female pattern hair loss and telogen effluvium, but these are associations, and no trial has yet shown that supplements alone regrow hair.
At The London PRP Clinic by The Wellness, a targeted blood panel through The Online GP by The Wellness is from £295, and a hair consultation with trichoscopy is from £300.
Shedding more as the days shorten? Message our doctors on WhatsApp or email team@thewellnesslondon.com.
Why vitamin D matters for hair
Vitamin D is made in the skin in sunlight and acts as a hormone throughout the body. Hair follicles carry vitamin D receptors, and laboratory studies show that the receptor is involved in starting each new growth cycle. People born with a faulty vitamin D receptor often lose their hair, which shows how important the pathway is to the follicle.
Vitamin D also helps regulate the immune system. That is one reason researchers have looked closely at its link with alopecia areata, where the immune system attacks hair follicles.
What the research shows
Alopecia areata. A consistent link
The clearest evidence is in alopecia areata. A 2020 meta-analysis in Dermatology and Therapy pooled 19 studies with 1,585 patients and 1,114 controls. People with alopecia areata had lower vitamin D levels and were about 4 times more likely to be deficient. The authors suggested screening and correcting deficiency but noted that no study had yet tested whether supplements change the course of the condition. Our guide is alopecia areata treatment.
Pattern hair loss and shedding. A probable link
Smaller studies and later meta-analyses have reported lower vitamin D in female pattern hair loss and telogen effluvium, the diffuse shedding that often follows illness or stress. The findings are less consistent than for alopecia areata, and they show an association, not proof that low vitamin D causes the hair loss.
What the research has not shown
There are no good-quality randomised trials showing that vitamin D supplements alone regrow hair in people who are not deficient. Taking high doses without a test is not a hair treatment, and too much vitamin D can be harmful.
Want your vitamin D and other markers checked together? Ask our doctors on WhatsApp.
Who is most likely to be low
People who spend little time outdoors, office workers and night-shift workers. People with darker skin, who need more sunlight to make the same amount of vitamin D. People who cover most of their skin outdoors. Older adults. People with coeliac disease, inflammatory bowel disease or previous weight-loss surgery, which reduce absorption. People with a higher body weight. Anyone in the UK between October and March, when the sun is too low for the skin to make enough.
Autumn is also when many people notice seasonal shedding, which we explain in autumn hair shedding.
Why vitamin D is rarely the whole story
Low vitamin D often travels with other causes of hair loss. In our experience, people with low vitamin D frequently also have low ferritin, a thyroid problem or underlying pattern hair loss. Correcting vitamin D while missing low iron is one of the most common reasons hair does not recover. That is why we test them together. See low ferritin and hair loss and thyroid hair loss.
What we test
You are assessed with a full scalp examination and trichoscopy, a magnified view of the follicles that shows whether hair is shedding, shrinking or being lost in patches, with standardised photographs so progress can be measured.
A blood panel arranged by The Online GP by The Wellness and processed by an accredited partner laboratory checks 25-hydroxyvitamin D alongside ferritin and full iron studies, full thyroid function with antibodies, B12, folate, zinc, full blood count and HbA1c, with hormonal markers where relevant. The reasoning behind each marker is in the hair loss blood panel.
How to treat it
Correcting a deficiency
If you are deficient, your doctor will recommend a treatment course and then a maintenance dose, and recheck your level after around 3 months to confirm it has recovered. If you are not deficient, the UK advice of 10 micrograms a day through autumn and winter still applies to most adults. Do not take high-dose supplements without a test.
Treating the hair loss itself
Once deficiencies are corrected, the hair loss is treated according to its cause. Pattern hair loss responds to minoxidil and PRP, with a 2025 meta-analysis of 43 randomised trials finding that PRP increases hair density. Our guides are PRP hair treatment London, the best hair loss treatment for women and the best hair loss treatment for men. The evidence across treatments is summarised in PRP success rates.
What to expect
Shedding linked to a deficiency usually slows a few months after levels recover, and visible thickening follows over 6 to 12 months, because hair grows at roughly 1 centimetre a month.
What it costs
At The London PRP Clinic by The Wellness, there are 3 ways to begin.
A targeted blood panel through The Online GP by The Wellness is from £295, or a comprehensive panel from £495, including vitamin D, iron studies and thyroid function.
A hair consultation with full scalp examination and trichoscopy is from £300, included at the first session if you go on to a course of PRP.
If treatment is right for you, PRP is from £450 per session or £1,215 for a course of 3.
Ask about a hair blood test. Message us on WhatsApp.
Why people choose The London PRP Clinic by The Wellness
Every treatment is performed by a GMC-registered doctor, and no clinician treats a patient here until they have completed 100 supervised treatments. Every hair plan begins with trichoscopy and a full blood panel, so vitamin D, iron, thyroid and hormonal causes are found together rather than one at a time. When correcting a deficiency is all you need, we say so.
We see patients at 10 Portman Square in Marylebone and the Light Centre in Belgravia. Across our work we report an 87 percent patient success rate, a 32 percent average density increase at 6 months in hair restoration and more than 187 five-star reviews.
Book your hair consultation. Message us on WhatsApp, email team@thewellnesslondon.com, or call +44 20 3951 3429.
Frequently asked questions about vitamin D and hair loss
Can low vitamin D cause hair loss?
Low vitamin D is linked to several types of hair loss, most clearly alopecia areata, and hair follicles depend on vitamin D signalling. Studies show an association rather than proof that low vitamin D alone causes hair loss.
Will vitamin D supplements regrow my hair?
If you are deficient, correcting it supports recovery. There is no good evidence that supplements alone regrow hair in people who are not deficient.
How much vitamin D should I take in the UK?
UK advice is that most adults should consider 10 micrograms a day during autumn and winter. Higher doses to correct a deficiency should be guided by a blood test and a doctor.
Is vitamin D linked to alopecia areata?
Yes. A 2020 meta-analysis of 19 studies found people with alopecia areata were about 4 times more likely to be vitamin D deficient.
What blood tests should I have for hair loss?
Vitamin D, ferritin and iron studies, full thyroid function with antibodies, B12, folate, zinc, full blood count and HbA1c, with hormonal markers where relevant.
How long does hair take to recover after correcting vitamin D?
Shedding usually slows a few months after levels recover, and visible thickening follows over 6 to 12 months.
This article is for information and does not replace personal medical advice. All treatments at The London PRP Clinic by The Wellness are performed by GMC-registered doctors. Reviewed by a GMC-registered doctor at The London PRP Clinic by The Wellness. Last updated October 2026.