Sunbathing Vitamin D

Vitamin D has been shown to be very important in activating stem cells in hair follicles and regulating skin biology (Bollag, 2012). It is believed that vitamin D, which allows for calcium to be processed for the human body, triggers the regrowth process of damaged skin cells, including those in the scalp, and allows for regeneration of cells vital to hair growth (Bikle, Tu, & Oda, 2015).

The link between vitamin D and hair growth has been further shown in a study done by Mazen, Ismail, Amr, Gammal, & Abdel-Hamid (2014), where four Egyptian families with vitamin D resistant genes were found to have hair loss and required Vitamin D supplements to treat the affects of total alopecia and hypocalcaemia. Vitamin D has also been shown to be helpful in hair growth through replacing hair follicles in rats with hair follicles pretreated with vitamin D (Aoi et al., 2012).

However, there are few direct studies that show a direct link between Vitamin D supplements and hair growth, as more studies have been done on the relationship between Vitamin D and their follicles than clinical trials of Vitamin D supplements and hair growth in humans. In addition, while treatment of Vitamin D deficiency was successful in the four Egyptian families with Vitamin D resistant genes, only one showed hair growth through the treatment (Mazen, Ismail, Amr, Gammal, & Abdel-Hamid, 2014). Nonetheless, there is a link between Vitamin D and the hair growth process, and so Vitamin D could possibly be used as a hair growth aid after a proper clinical trial has been performed.

How Does Vitamin D Promote Hair Growth?

The two most important inactive forms of vitamin D – D2 and D3, known as calciferol – play a significant part in your well-being and hair health. Vitamin D2 (ergocalciferol) can’t be synthesized by humans and should therefore be taken from your diet. On the other hand, vitamin D3 (cholecalciferol) is synthesized in your skin in the presence of sunlight. D2 and D3 are then converted to calcitriol, which is the active form of vitamin D – this takes place in the kidneys or is carried out by the cells of your immune system. It is then transported to your organs and systems by specific proteins.

What is the Connection Between Vitamin D and Hair Health?

Vitamin D is very important to cell division and the process where new cells replace the old ones that are no longer functional. It is also involved in cell differentiation and the proper functioning of the immune system. However, the regulation of calcium and phosphate levels in the human body is the first and most important purpose of vitamin D, which ensures your bones, skin, nails and hair are strong and well nourished.

In the absence of vitamins and minerals, the hair follicle will shrink and changes in the growth cycle occur, which may cause your hair to become brittle and thin. Vitamin D improves hair growth and aspect in a number of ways:

  • It activates the cells within the hair shaft
  • It improves the look and feel of the growing hair
  • It stimulates and nourishes the hair follicle. Vitamin D receptors (VDRs) have an important contribution to the follicle growth cycles. According to scientific research, inactive vitamin D receptors in mice always resulted in hair loss
  • It stimulates hair growth. Vitamin D analogs (D2 and D3 supplements) reversed hair loss in mice, and cancer patients who have lost hair due to chemotherapy reported significant improvements after the use of vitamin D supplements. Through their direct action on keratinocytes (the cells found responsible for inactive vitamin D receptors), vitamin D analogs stimulated hair growth in mice.

How Can You Boost Vitamin D Levels?

Remember that getting more vitamin D from your diet and exposure to sunlight doesn’t magically grow hair. There are many other factors involved in hair loss/growth, and the best way to assess your situation is to speak to a dermatologist and perform the necessary blood tests. Moreover, doctors don’t recommend exposure to sunlight due to the increased risk of developing skin cancer, but as long as you get to spend more time outdoors without getting sunburned, everything should be perfectly safe. If you live in a sunny area, remember to use sunscreen with a good UV protection factor (SPF 15 at least). In terms of diet, fatty fish is a great source of vitamin D – catfish, salmon, mackerel and tuna for example. Other dietary sources include, but are not limited to whole eggs, liver, mushrooms and omega-3 fish oil.


  1. Aoi, N., Inoue, K., Chikanishi, T., Fujiki, R., Yamamoto, H., Kato, H., Yoshimura, K. (2012). 1 ,25-Dihydroxyvitamin D3 Modulates the Hair-Inductive Capacity of Dermal Papilla Cells: Therapeutic Potential for Hair Regeneration. Stem Cells Translational Medicine, 1(8), 615-626. doi:10.5966/sctm.2012-0032
  2. Bikle, D. D., Tu, C., & Oda, Y. (2015). Calcium and Vitamin D Signalling in the Epidermal Response to Wounding [Abstract]. Immunology‚ Endocrine & Metabolic Agents in Medicinal Chemistry IEMAMC, 14(3), 128-136. doi:10.2174/187152221403150521104752
  3. Bollag, W. B. (2012). Mediator1: An Important Intermediary of Vitamin D Receptor–Regulated Epidermal Function and Hair Follicle Biology. J Investig Dermatol Journal of Investigative Dermatology, 132(4), 1068-1070. doi:10.1038/jid.2012.25
  4. Mazen, I., Ismail, S., Amr, K., Gammal, M. E., & Abdel-Hamid, M. (2014). Hereditary 1,25-dihydroxyvitamin D-resistant rickets with alopecia in four Egyptian families: Report of three novel mutations in the vitamin D receptor gene. Journal of Pediatric Endocrinology and Metabolism, 27(9-10), 873-878. doi:10.1515/jpem-2013-0443