Vitamin D Test
Measure your 25-OH vitamin D level with a simple home fingerstick kit. Results reviewed by a GMC-registered physician and returned in 3 to 5 working days.
£29.00
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Overview
What Is Hair Loss?
Hair loss — medically referred to as alopecia — occurs when the rate of hair shedding exceeds the rate of new hair growth, resulting in visible thinning, patchiness, or a receding hairline. While losing 50–100 hairs per day is considered normal as part of the hair growth cycle, hair loss as a clinical symptom involves shedding well beyond this threshold, often exceeding 150 hairs per day, alongside noticeable changes in hair density.
Many cases of hair loss have measurable, treatable causes rooted in nutritional status or hormonal balance. Ferritin — the body’s iron storage protein — is one of the most common culprits; ferritin below 30 µg/L is strongly associated with telogen effluvium, a form of diffuse shedding triggered when the body prioritises iron for vital organs over hair follicle function. Similarly, thyroid hormones regulate the hair growth cycle directly, and both underactive thyroid (elevated TSH) and overactive thyroid can cause significant hair thinning.
Hormonal hair loss is also driven by androgens such as testosterone and its conversion to DHT via 5-alpha reductase, particularly in women with PCOS where excess androgens miniaturise hair follicles on the scalp. Deficiencies in zinc, folate, and vitamin D can also impair the hair follicle’s ability to cycle correctly, contributing to diffuse or patchy hair loss.
Hair Loss vs. Normal Shedding
Losing 50–100 hairs daily is a normal part of the hair growth cycle and does not constitute hair loss. Hair loss as a symptom involves noticeable thinning, patchy bald areas, or consistent shedding of more than 150 hairs per day — particularly when accompanied by changes in hair texture or scalp health.
Related experience
Common Symptoms Associated With Hair Loss
Hair loss rarely occurs in isolation — it commonly accompanies other signs of nutritional or hormonal imbalance.
Fatigue
Low ferritin or thyroid dysfunction reduces energy alongside hair growth
Cold Intolerance
Feeling cold all the time is a hallmark of underactive thyroid
Poor Sleep
Hormonal imbalances that cause hair loss often disrupt sleep quality
Low Mood
Thyroid disorders and nutritional deficiencies affect mood and motivation
Irregular Periods
PCOS and hormonal imbalance can drive both hair loss and menstrual irregularity
Brittle Nails
Zinc, biotin, and iron deficiencies affect both nails and hair simultaneously
The big picture
What Causes Hair Loss?
Hair loss can stem from nutritional deficiencies, hormonal disruption, thyroid dysfunction, or a combination of these factors.
What to measure
Biomarkers Associated With Hair Loss
These blood biomarkers are the most clinically relevant starting points for investigating hair loss.
Ferritin
Iron storage protein; levels below 30 µg/L are associated with telogen effluvium
TSH
Thyroid-stimulating hormone; elevated TSH indicates underactive thyroid driving hair loss
Free T4
Active thyroid hormone; low free T4 confirms hypothyroidism and impaired hair cycling
Testosterone (Total)
Elevated total testosterone in women suggests androgen-driven follicle miniaturisation
SHBG
Low SHBG increases free androgen availability, worsening hormone-related hair loss
Oestradiol
Post-menopausal oestrogen decline is closely linked to diffuse hair thinning
Vitamin D (25-OH)
Vitamin D receptors in hair follicles regulate growth cycling; deficiency causes shedding
Zinc
Zinc is essential for keratin synthesis; deficiency causes brittle, thinning hair
Underlying causes
Conditions Associated With Hair Loss
Several underlying conditions are known to cause or accelerate hair loss through measurable hormonal or nutritional mechanisms.
Iron Deficiency
The most common nutritional cause of diffuse hair loss in women
Hypothyroidism
Underactive thyroid disrupts the anagen (growth) phase of the hair cycle
PCOS
Androgen excess in PCOS causes androgenetic alopecia on the scalp
Vitamin D Deficiency
Vitamin D deficiency impairs follicle stem cell activation and cycling
Hashimoto's Thyroiditis
Autoimmune thyroid inflammation can cause patchy alopecia areata in addition to diffuse thinning
Getting answers
How Hair Loss Is Investigated
A structured approach helps pinpoint the cause of hair loss quickly and avoid unnecessary treatments.
1
Check Ferritin First
Request serum ferritin as a standalone test or as part of an iron panel. A ferritin below 30 µg/L warrants iron supplementation and dietary review before investigating other causes.
2
Assess Thyroid Function
A TSH and free T4 panel identifies hypothyroidism or subclinical thyroid dysfunction — both of which are reversible causes of hair loss when treated appropriately.
3
Test Hormonal Profile
In women, checking testosterone, SHBG, oestradiol, LH and FSH identifies PCOS or menopausal-related hormonal shifts. In men, testosterone levels and SHBG provide insight into androgen-driven alopecia.
Recommended testing
Recommended Blood Tests
Private blood tests analysed by UK-accredited laboratories.
Essential Vitamin and Mineral Panel
Check your levels of vitamin D, B12, folate, ferritin, and zinc in one convenient test. Home fingerstick kit available. GMC physician review included.
£79.00
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Female Hormone Profile
A six-marker hormone panel measuring oestradiol, progesterone, LH, FSH, testosterone, and SHBG.
£79.00
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Prolactin and Pituitary Check
A targeted three-marker panel measuring prolactin, LH, and FSH to investigate pituitary function, irregular periods.
£69.00
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Magnesium Test
Check your serum magnesium level to investigate muscle cramps, fatigue, palpitations, or poor sleep. Simple home fingerstick kit. GMC physician review.
£29.00
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Everyday contributors
Lifestyle Factors That Can Contribute
Lifestyle factors can significantly influence hair loss severity and recovery speed alongside any clinical treatment.
Iron-Rich Diet
Red meat, lentils, and dark leafy greens help maintain ferritin levels in the optimal range for hair growth
Sun Exposure
Sensible daily sun exposure supports vitamin D levels, which regulate follicle stem cell activity
Stress Management
Chronic cortisol elevation prolongs the telogen (resting) phase of the hair cycle; mindfulness and adequate sleep help normalise this
Protein Intake
Hair is primarily keratin — inadequate dietary protein limits the raw material available for hair shaft production
Gentle Hair Care
Reducing heat styling and tight hairstyles (traction) prevents additional mechanical hair loss on top of nutritional causes
Thyroid-Supportive Nutrition
Adequate selenium and iodine intake supports thyroid hormone synthesis; Brazil nuts are a practical selenium source
Safety first
When To Seek Medical Advice
Most hair loss has a treatable cause, but certain warning signs should prompt prompt medical review.
Red flags — speak to a doctor
These can point to a more serious underlying cause and should not be ignored.
- Sudden onset of circular or patchy bald areas (alopecia areata) appearing within days to weeks
- Complete or near-complete loss of body hair, eyebrows, or eyelashes alongside scalp loss
- Scalp scarring, persistent redness, or scaling associated with hair loss, which may indicate a scarring alopecia requiring specialist assessment
- Hair loss accompanied by a spreading rash, joint pain, or fatigue — which may suggest a systemic autoimmune condition such as lupus
Common questions
Frequently Asked Questions
Iron deficiency is the most common nutritional cause of hair loss in women, particularly in those who menstruate heavily. Low ferritin levels — below 30 µg/L — are associated with telogen effluvium, where hair prematurely enters the shedding phase. Vitamin D deficiency, zinc insufficiency, and folate deficiency are also frequently implicated. A comprehensive nutritional blood test can identify which deficiencies are contributing.
Yes — both hypothyroidism (underactive thyroid) and hyperthyroidism (overactive thyroid) can cause diffuse hair loss. Thyroid hormones regulate every phase of the hair growth cycle; when levels fall outside the normal range, hair follicles shift into the resting phase prematurely. A TSH and free T4 test is a straightforward way to rule out thyroid-related hair loss.
Once iron stores are replenished and ferritin rises above 70 µg/L (the level generally associated with optimal hair growth), most people notice reduced shedding within 2–3 months. Visible regrowth of new hair typically takes 4–6 months, as the hair growth cycle itself takes time to restart. Consistent supplementation and dietary improvement are important throughout this period.
Paradoxically, elevated — not low — testosterone and androgens cause the most common form of female pattern hair loss. In conditions like PCOS, raised androgens are converted to DHT, which binds to scalp follicle receptors and miniaturises them over time. Low SHBG compounds this by increasing the amount of free testosterone available to act on hair follicles.
A targeted hair loss blood test panel should include ferritin, TSH, free T4, testosterone, SHBG, vitamin D, zinc, and folate. For women, adding oestradiol, LH, and FSH provides a fuller hormonal picture. Trupoint Health’s Essential Vitamins Panel and PCOS Hormone Screen cover the most common investigative routes.
Keep exploring
Related Symptoms
Related Biomarkers
Related Conditions
Sources
References
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Rushton DH — View source
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Trüeb RM — View source
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NHS England — View source
This page is for general information only and does not replace personalised medical advice. If you are worried about your health, please speak to a qualified healthcare professional. Trupoint Health blood tests are analysed by UK-accredited laboratories.