Understanding if and How Does Hair Grow Back After Taking Vitamin D?

October 12, 2025 •

4 min read

Approximately 41% of US adults have insufficient levels of vitamin D, a deficiency often linked to hair thinning and loss. For those with a confirmed deficit, the question, 'Does hair grow back after taking vitamin D?' is a common one, with the answer depending on a variety of factors related to the underlying cause of the hair loss.

Quick Summary

Correcting a vitamin D deficiency can reverse associated hair loss, with regrowth typically visible within 6 to 12 months. This process is influenced by the severity of the deficiency, genetics, and other nutritional factors, necessitating proper diagnosis and a holistic treatment approach.

Key Points

Hair Follicle Function: Vitamin D is critical for regulating the hair growth cycle by activating vitamin D receptors (VDRs) in hair follicles.
Deficiency Link: Low vitamin D levels are linked to hair loss conditions like androgenetic alopecia and alopecia areata due to disruption of the hair cycle.
Potential for Regrowth: If hair loss is caused by vitamin D deficiency, regrowth is possible once levels are corrected through supplementation and diet.
Gradual Timeline: Expect hair regrowth to be a slow process, with noticeable improvement often taking 6 to 12 months after starting treatment.
Holistic Approach: Successful recovery requires more than just supplements; it involves a balanced diet, stress reduction, and addressing other potential health issues.
Professional Diagnosis: It is essential to confirm a vitamin D deficiency and rule out other causes of hair loss with a doctor before beginning supplementation.

The Critical Role of Vitamin D in Hair Growth

Often called the 'sunshine vitamin,' vitamin D is a fat-soluble nutrient essential for overall health, with a specific and significant impact on hair follicle function. Its role in hair growth begins at a fundamental level, influencing the cycle of hair production. The hair growth cycle consists of three main phases: anagen (growth), catagen (transition), and telogen (rest). Vitamin D plays a crucial role in regulating this cycle, particularly in initiating the anagen phase where new hair is actively produced.

Central to this process are vitamin D receptors (VDRs) located within the hair follicles. Studies have shown that when these receptors are absent or impaired, hair growth is significantly disrupted, leading to conditions like alopecia. A sufficient supply of vitamin D helps these receptors function correctly, ensuring that hair follicles can operate efficiently to produce healthy, thick hair.

Connecting Vitamin D Deficiency to Hair Loss

When vitamin D levels are low, this intricate process is thrown off balance. A deficiency can shorten the anagen (growth) phase and prematurely push hair follicles into the telogen (rest) phase, causing increased shedding and noticeable thinning. Research has identified strong links between low vitamin D levels and several types of hair loss, highlighting its importance beyond just general hair health.

Common hair loss conditions linked to low vitamin D include:

Alopecia Areata: An autoimmune condition where the immune system attacks hair follicles, leading to patchy hair loss. Studies indicate that people with alopecia areata often have lower vitamin D levels.
Androgenetic Alopecia: Also known as male or female pattern baldness. While primarily genetic, some reviews have noted a correlation between low vitamin D and this form of hair loss.
Telogen Effluvium: A temporary hair loss condition often triggered by stress, illness, or nutritional deficiencies. A severe vitamin D deficiency can cause or exacerbate this type of shedding.

Does Hair Grow Back After Taking Vitamin D? The Regrowth Process

For hair loss caused primarily by a vitamin D deficiency, the answer is often yes, hair can regrow after taking supplements and restoring levels. However, this is not a magic cure and depends on various factors, most importantly, the confirmation that the deficiency is the root cause.

Regrowth is a gradual process. Once vitamin D levels are corrected, the hair follicles must resume their normal cycling. The over-shedding phase often slows first, which can feel like a positive sign of stabilization. From there, new, healthier hair begins to grow from the reactivated follicles. The timeline for noticeable regrowth varies from person to person, but patience is key.

A Timeline for Hair Regrowth

As with any biological process, stimulating hair growth takes time. Setting realistic expectations can help manage the journey to recovery.

1–3 Months: You may notice a decrease in excessive hair shedding. New, fine 'baby hairs' might begin to appear, although they may not be immediately obvious.
6–8 Months: For many, this period marks a more visible increase in hair density and thickness. The new hairs have had more time to mature and grow.
12+ Months: A full recovery can take up to a year or longer, especially if the hair loss was severe or prolonged. Consistent supplementation and a healthy lifestyle are vital during this phase.

Comprehensive Approach Beyond Supplementation

While correcting a vitamin D deficiency is crucial, a holistic approach is often necessary for optimal hair health. Relying solely on a supplement without addressing other potential issues might lead to disappointing results. For example, a 2022 study on female pattern hair loss found that oral vitamin D alone wasn't as effective as when combined with topical treatments like minoxidil.

Comparing Hair Loss Causes


Feature	Hair Loss from Vitamin D Deficiency	Genetic Hair Loss (AGA)	Stress-Related Hair Loss (Telogen Effluvium)
Primary Cause	Insufficient vitamin D levels impacting hair follicle function.	Hereditary sensitivity of hair follicles to DHT hormones.	A major physical or psychological stressor, like illness or trauma.
Reversibility	Often reversible with proper supplementation and diet.	Can be managed, but not typically fully reversible. Requires ongoing treatment.	Reversible, with hair often regrowing on its own after the stressor is removed.
Pattern	Diffuse thinning across the scalp, increased shedding.	Follows a predictable pattern (e.g., receding hairline for men, widened part for women).	Diffuse thinning across the scalp.
Treatment	Vitamin D supplementation, dietary changes, sun exposure.	Medical treatments like Minoxidil or Finasteride; hair transplants.	Identifying and addressing the root stressor; nutritional support.

Other Factors Influencing Regrowth

Balanced Diet: Ensure sufficient intake of other vital nutrients, including iron, zinc, and B vitamins, all of which support healthy hair.
Stress Management: High stress levels can disrupt the hair growth cycle. Incorporate relaxation techniques like yoga or meditation.
Overall Health: Underlying medical conditions like thyroid issues, hormonal imbalances, and autoimmune diseases can affect hair growth. A doctor should rule out these possibilities.
Scalp Health: Maintain a healthy scalp by avoiding harsh chemical treatments and styling practices that cause traction.
Supplements & Combinations: A doctor may recommend combining vitamin D supplements with other treatments for enhanced results, as seen in the case of minoxidil. For a broader perspective on hair health, exploring resources on overall wellness can be helpful, such as this guide from Harvard Health.

Conclusion

Restoring hair lost due to a vitamin D deficiency is possible, but it requires confirmation of the cause through a blood test and a commitment to restoring your vitamin D levels. The regrowth process is not instantaneous and can take several months to a year, depending on individual factors. While supplements play a vital role, success is best achieved through a holistic approach that includes a balanced diet, stress management, and addressing any other contributing health issues. Consulting a healthcare professional, such as a dermatologist, is the most effective way to determine the precise cause of your hair loss and create a personalized treatment plan for the best chance of successful regrowth.

Frequently Asked Questions

While some people notice reduced shedding within 2 to 3 months, visible hair regrowth often takes 6 to 12 months after vitamin D levels are successfully restored.

Hair loss due to vitamin D deficiency is often reversible if corrected early. However, a severe and prolonged deficiency can disrupt the hair growth cycle long-term, potentially leading to more persistent thinning.

The only definitive way to know is through a blood test (serum 25-hydroxyvitamin D) ordered by a doctor. Other symptoms like fatigue, bone pain, and mood changes may also indicate a deficiency.

Research suggests that Vitamin D3 (cholecalciferol) is the more effective form for raising serum vitamin D levels compared to D2. It's often recommended for supplementation.

Besides vitamin D, deficiencies in nutrients such as iron, zinc, and B vitamins (like B12 and biotin) are also linked to hair loss. It’s important to have a comprehensive look at your overall nutritional status.

Sunlight is a natural source of vitamin D, but obtaining sufficient amounts can be challenging depending on your location, time of year, skin pigmentation, and use of sunscreen. Supplementation is often necessary to ensure adequate levels.

It is crucial to follow a doctor's recommendation for dosage, which is determined by a blood test. Taking excessively high doses can lead to vitamin D toxicity, which can have negative health consequences.