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Updated: May 25, 2026
12:37
Pharmacologic Induction of Epidermal Melanin and Protection Against Sunburn in a Humanized Mouse Model
Published on: September 7, 2013
Human skin pigmentation, migration and disease susceptibility
Nina G Jablonski1, George Chaplin
1Department of Anthropology, The Pennsylvania State University, University Park, PA 16802, USA. ngi2@psu.edu
Summary
Human skin pigmentation balances UV protection and vitamin D production. Modern migrations and lifestyles create mismatches, increasing risks for diseases like rickets, multiple sclerosis, and melanoma.
Area of Science:
- Human evolutionary biology
- Dermatology
- Nutritional science
Background:
- Human skin pigmentation evolved as a balance between protection from ultraviolet radiation (UVR) and vitamin D synthesis.
- Ancestral Homo sapiens in equatorial regions had dark skin (eumelanin) for UVR protection.
- Migrations to lower UVR regions favored lighter skin for vitamin D production.
Purpose of the Study:
- To examine the health consequences of mismatches between an individual's skin pigmentation and their current UVR environment.
- To illustrate how modern lifestyle changes exacerbate these risks.
- To highlight the role of UVR and vitamin D in diseases such as nutritional rickets, multiple sclerosis (MS), and cutaneous malignant melanoma (CMM).
Main Methods:
- Review of evolutionary and epidemiological data on human skin pigmentation and UVR exposure.
- Analysis of disease aetiology in relation to genetic and environmental factors, particularly UVR and vitamin D.
- Case studies illustrating the impact of altered UVR regimes on health outcomes.
Main Results:
- Dispersal from the tropics led to selection for lighter skin to enhance vitamin D synthesis in low UVB environments.
- Modern migrations and lifestyle changes (urbanization, diet) place individuals in mismatched UVR environments.
- Mismatches increase risks for nutritional rickets, MS, and CMM, with MS etiology showing complex gene-environment interactions.
Conclusions:
- Altered UVR exposure due to migration and lifestyle changes poses significant health risks.
- Vitamin D deficiency resulting from low UVB levels is a major concern in the 21st century.
- Understanding the interplay of genetics, skin type, and UVR is crucial for public health strategies.
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