Vitamin D is a fat-soluble vitamin known for maintaining bone health by increasing blood concentrations of calcium and phosphorus. It also contributes to an effective immune system and normal muscle contraction.
However, its blood concentration is considered insufficient in more than 50% of the French population, according to INSERM data.
In addition to the issues such a deficiency may induce on general health, scientific studies have shown that a deficiency in vitamin D could negatively impact hair growth and the regulation of the hair cycle.
What is the link between vitamin D and hair? I answer your questions.
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What is the role of vitamin D on hair fibre?
Regulating the anagen phase
To promote normal hair fibre growth and ensure healthy hair, hair follicles at the base of the scalp need certain nutrients.
Vitamin D is one of them and is believed to play a role in regulating the anagen phase of the hair (or growth phase). This is indicated by this study.
Assisting in follicle regeneration
According to this study, certain vitamin D receptors are expressed in the keratinocytes of hair. Once activated, they allow for cellular differentiation and proliferation, as well as follicle regeneration.
A factor in hair growth
If your vitamin D intake is insufficient, the growth cycle of your hair could be disrupted.
Among other things, hair follicles could prematurely enter the resting phase, which can lead to a rapid hair loss and reduced hair density.
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Vitamin D deficiency, what impact on hair?
A vitamin D deficiency leads to hair loss
According to a 2021 review, the majority of scientific studies on the topic show a clear inverse relationship between vitamin D levels and the presence of various non-scarring alopecias (telogen effluvium, androgenetic alopecia, alopecia areata) or scarring alopecia.
A scientific study also showed that a deficiency in vitamin D could be involved in alopecia areata, a form of autoimmune hair loss.
But it’s not the only factor
Note: even though a vitamin D deficiency can lead to higher than normal hair loss, it is not the only potential cause.
Hormonal imbalances, nutritional deficiencies in iron, proteins, or zinc, pathologies, genetic predispositions, or a period of intense stress can alter the hair cycle and increase hair loss.
To improve your issue, I recommend getting a comprehensive assessment from healthcare professionals to determine the true cause of your hair loss.
Should you supplement with vitamin D for healthier hair?
If a vitamin D deficiency disrupts hair growth and plays a role in premature hair loss, it can be assumed that increasing intake through supplementation might be beneficial. To strengthen hair, prevent loss, and contribute to their growth, for example.
However, scientific research seems to be contradictory and does not show sufficient significant results on the benefits of vitamin D supplementation for hair health, even in deficient individuals.
New studies on the subject could be interesting.
How to maintain a good level of vitamin D?
If you wish to have a beautiful head of hair, sufficient serum levels of vitamin D are essential. For this, I recommend:
- exposing yourself to sunlight for 15 to 30 minutes a day, depending on your skin type. Be sure to wear sunscreen and avoid the hottest hours of the day.
- consuming fatty fish several times a week, as well as eggs or fortified dairy products.
- to supplement yourself during autumn and winter periods, when sunlight tends to be scarce. My recommendation? Vitamin D3 (cholecalciferol) supplements, better absorbed than those based on vitamin D2. Before starting any course, consult your doctor to assess your vitamin D level and needs.
Sources and scientists
- Demay MB et Al, 2007, Role of the vitamin D receptor in hair follicle biology
- Cianferotti L et Al, 2007, Vitamin D receptor is essential for normal keratinocyte stem cell function.
- Saini K et Al, 2021, Role of vitamin D in hair loss: A short review.
- Thompson JM et Al, 2017, The Role of Micronutrients in Alopecia Areata: A Review.
- Klein EJ et Al, 2022, Supplementation and hair growth: A retrospective chart review of patients with alopecia and laboratory abnormalities.
