Does vitamin D help hair growth? Exploring the connection for a healthier scalp

October 22, 2025 •

2 min read

Research consistently shows a strong link between vitamin D deficiency and various forms of hair loss, including alopecia areata. So, does vitamin D help hair growth? The answer lies in its critical role in regulating the hair follicle cycle, where a sufficient supply can promote healthy growth and combat shedding.

Quick Summary

Vitamin D plays a key role in regulating the hair growth cycle by activating hair follicle receptors and supporting keratin production. A deficiency can disrupt this process, potentially leading to excessive shedding or thinning. Restoring optimal levels, through sun exposure or supplements, may support healthier hair.

Key Points

Supports hair growth cycle: Vitamin D, through its receptor (VDR), helps regulate the hair follicle cycle and promote the growth phase (anagen).
Prevents premature shedding: A deficiency can disrupt the hair cycle, leading to premature shedding and overall hair thinning over time.
Associated with alopecia areata: Numerous studies have found a strong link between low vitamin D levels and autoimmune hair loss, such as alopecia areata.
Not a cure-all solution: While important, correcting a deficiency is not a magic bullet for all hair loss and should be part of a comprehensive strategy.
Sources beyond supplements: You can get vitamin D from sunlight exposure, fatty fish, fortified dairy, and mushrooms, in addition to oral supplements.
Requires medical guidance: Excessive vitamin D intake can be toxic, so it is crucial to consult a doctor before starting a supplement regimen.

The Science Behind Vitamin D and Hair Follicles

Vitamin D is a prohormone whose active form interacts with the Vitamin D Receptor (VDR) in hair follicles. This VDR is crucial for the hair follicle cycle, particularly in starting the anagen (growth) phase. Sufficient vitamin D helps hair follicles function correctly and produce new hair. A deficiency disrupts this cycle, potentially shortening the growth phase and increasing shedding. Animal studies indicate the VDR's importance for preventing alopecia.

The Link Between Vitamin D Deficiency and Hair Loss

Low vitamin D levels are significantly linked to several types of hair loss (alopecia). While a deficiency isn't always the sole cause, it's a major factor in certain conditions.

Symptoms of a Vitamin D Deficiency

Besides hair loss, a deficiency can manifest through other symptoms:

Common symptoms include:

Fatigue
Muscle weakness or pain
Frequent infections
Slow wound healing
Depression
Memory issues

How Vitamin D Deficiency Relates to Specific Hair Loss Conditions

Alopecia Areata: Studies consistently show lower vitamin D levels and higher deficiency rates in patients with this autoimmune condition. Severity often correlates with lower vitamin D.
Androgenetic Alopecia (Pattern Hair Loss): Low vitamin D is associated with both male and female pattern baldness. Adequate levels may support follicle health despite the primary genetic influence.
Telogen Effluvium: Vitamin D deficiency can trigger this temporary shedding by disrupting the hair cycle and increasing shedding. Correcting the deficiency can help reverse it.

Sources of Vitamin D for Hair Health

Vitamin D comes from sunlight exposure, diet, and supplements. A mix is often needed for optimal levels.

Foods high in vitamin D include:

Fatty fish (salmon, mackerel)
Cod liver oil
Egg yolks
UV-exposed mushrooms
Fortified foods (milk, cereals)

Supplementing with Vitamin D

Supplements can help restore levels in cases of confirmed deficiency. Consult a doctor for diagnosis and dosage due to potential harm from excessive intake.

Vitamin D2 vs. D3 for Hair Growth


Feature	Vitamin D2 (Ergocalciferol)	Vitamin D3 (Cholecalciferol)
Source	Plants/fungi exposed to UV	Skin upon sun exposure, animal sources
Efficacy	Less potent at raising/sustaining blood levels	More effective at raising/maintaining levels
Recommendation	Often prescribed for specific conditions	Generally preferred and widely available
Availability	Prescription	Over-the-counter

Conclusion

Vitamin D is important for hair health, especially for those with a deficiency. Ensuring adequate levels through diet, sun, or supplements can support the hair growth cycle. However, it's one factor among many, including genetics, hormones, and overall nutrition. Always consult a healthcare professional for hair loss diagnosis and treatment.

For more on vitamin D, see the NIH Office of Dietary Supplements.

Frequently Asked Questions

Yes, chronic or severe vitamin D deficiency has been shown to cause hair loss by interfering with the hair follicle cycle. When levels are too low, the hair growth phase can be disrupted, leading to increased shedding and thinning.

Vitamin D interacts with receptors in the hair follicles, which are crucial for initiating and regulating the hair growth cycle. This interaction ensures the follicles can function properly and maintain the anagen (growth) phase.

Low vitamin D levels are associated with several types of hair loss, including alopecia areata (an autoimmune condition), androgenetic alopecia (pattern baldness), and telogen effluvium (temporary shedding).

The body can produce vitamin D from sunlight exposure. Other sources include fatty fish (salmon, mackerel), fortified foods like milk and cereals, and supplements. Supplements are often recommended, especially during winter months when sun exposure is limited.

If hair loss is due to a deficiency, improvements may take several months. Full hair regrowth can be a gradual process, and consistency is key. It is best to consult a healthcare provider for personalized advice.

No. While helpful for deficiency-related hair loss, a vitamin D supplement is not a universal cure. Hair loss can be caused by many factors, including genetics, hormones, and stress. It should be part of a holistic treatment approach.

Yes, vitamin D is fat-soluble and can build up to toxic levels in the body, leading to hypercalcemia. It is crucial to follow a doctor's recommendation for dosage, especially with supplements.