These are simple, fundamental short videos to inspire further reseach on your own to inquire the role melanin plays in our health, from Vitamin D to skin cancer. Please take time out to identify evidence based medicine research in the literature in reference to medications that treat skin diseases and in particular skin cancers and/or the use of Vitamin D in treating certain diseases. Share your findings with your fellow classmates for them to add further comments. Watching below takes about 20 minutes, will take longer when stopping and starting to take notes
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13 minutes
Melanin, a polymer that is produced by melanocytes, is known to give skin and hair its pigmentation. It is broken up into two different types: pheomelanin and eumelanin. Pheomelanin gives off a red or yellow pigmentation and eumelanin gives off a brown or black pigmentation. Depending on a person’s location and UV exposure, they may have one of the two types of melanin. For example, people who live closer to the equator are more likely to develop eumelanin because they are in a direct relationship with the sun compared to people who live closer to the poles who would have pheomelanin. Although over-exposure to UV light can be harmful such as causing melanoma which is a mutation in the DNA sequence, it can also provide benefits by stimulating the production of vitamin D which regulates calcium and promotes bone growth. Vitamin D can also help in treating autoimmune disorders such as vitiligo and healing burns.
Vitiligo
This autoimmune skin disorder can be described as pigmented macules of different sizes spread out across the surface of the skin. Vitiligo is caused by melanocytes being destroyed at the cutaneous layer. Even though vitiligo affects a small percentage of the population, it can affect different types of people independent of the skin tone. It not only has a physical effect on the skin, but also a psychological effect on the individual from rejection in society. A systematic review found that topical vitamin D analogues may be able to boost pigmentation within the skin. The active form of vitamin D (1,25-dihydroxyvitamin D3) has a wide range of functions from regulating calcium, to bone growth, to preventing or treating certain diseases such as osteoporosis, psoriasis, and vitiligo. There were some studies that showed how topical vitamin D3 analogues such as calcipotriol and tacalcitol used with or without ultraviolet light or corticosteroids may enhance pigmentation in patients with vitiligo. Furthermore, numerous studies demonstrated that the vitamin D3 analogues used in combination with PUVA, NBUVB, or an excimer laser are effective and safe in treatment compared to placebo with PUVA. This is because calcipotriol works on melanocytes, inflammation mechanisms, and other immunomodulatory systems because it can activate melanin production.
Burn Healing
Burns can damage the healthy layer of skin. Depending on how severe the burn is, it can also disrupt the production of vitamin D permanently. Vitamin D is proven to enhance wound healing and improve the immune system which could protect burn patients from serious infection. Because of this reason, vitamin D supplementation has become a significant source for these specific types of patients. When a patient experiences a severe burn, their vitamin D levels can drop. This is dependent on the burned BSA. A study was conducted to analyze the correlation between low vitamin D levels in the body with healing time in burn victims. It was found that patients were more likely to not only have longer healing time, but also increased hospitalization time. A different study that was conducted by Oxford University, demonstrated that patients who did not have a vitamin D deficiency were more likely to have a lower burned BSA which could contribute to faster healing time. The lack of vitamin D in certain patients was due to reduced UV exposure which led to longer hospitalization and prolonged healing time. In order to decrease hospitalization time, intensive rehab centers for burn patients need to consider early initiation of vitamin D supplementation.
References
AlGhamdi K, Kumar A, Moussa N. (2013). The role of vitamin D in melanogenesis with an emphasis on vitiligo. Indian J Dermatol Venereol Leprol. 79(6):750-8. doi: 10.4103/0378-6323.120720. PMID: 24177606.
Cho, Y. S., Seo, C. H., Joo, S. Y., & Ohn, S. H. (2020). The association between vitamin D levels and burn factors in different burn types. Burns & trauma, 8, tkaa018. https://doi.org/10.1093/burnst/tkaa018