Increased 25(OH)D3 level in redheaded people: Could redheadedness be an adaptation to temperate climate?
Autor: | Kateřina Sýkorová, Marie Bičíková, Vojtěch Fiala, Jana Hlaváčová, Ludmila Máčová, Šárka Kaňková, Jaroslav Flegr |
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Rok vydání: | 2020 |
Předmět: |
Adult
Male 0301 basic medicine Aging medicine.medical_specialty Climate Skin Pigmentation Dermatology Biology Biochemistry Evolution Molecular 030207 dermatology & venereal diseases 03 medical and health sciences chemistry.chemical_compound Folic Acid 0302 clinical medicine Blood serum Internal medicine medicine Temperate climate Vitamin D and neurology Humans Hair Color Molecular Biology Calcifediol Suntan Provitamin Alopecia European population Middle Aged Adaptation Physiological 030104 developmental biology Endocrinology Folic acid chemistry Case-Control Studies Sunlight Female Adaptation Melanin pigment |
Zdroj: | Experimental Dermatology. 29:598-609 |
ISSN: | 1600-0625 0906-6705 |
Popis: | About 1-2% of European population are redheaded, meaning they synthesize more pheomelanin than eumelanin, the main melanin pigment in humans. Several mutations could be responsible for this phenotype. It has been suggested that corresponding mutations spread in Europe due to a founder effect shaped either by a relaxation of selection for dark, UV-protective phenotypes or by sexual selection in favour of rare phenotypes. In our study, we investigated the levels of vitamin D precursor 25(OH)D3 (calcidiol) and folic acid in the blood serum of 73 redheaded and 130 non-redheaded individuals. In redheaded individuals, we found higher 25(OH)D3 concentrations and approximately the same folic acid concentrations as in non-redheaded subjects. 25(OH)D3 concentrations correlated with the intensity of hair redness measured by two spectrophotometric methods and estimated by participants themselves and by independent observers. In non-redheaded individuals, 25(OH)D3 levels covaried with the amount of sun exposure and intensity of suntan while in redheaded individuals, this was not the case. It suggests that increased 25(OH)D3 levels in redheaded individuals are due to differences in physiology rather than in behaviour. We also found that folic acid levels increased with age and the intensity of baldness and decreased with the frequency of visiting tanning salons. Our results suggest that the redheaded phenotype could be an evolutionary adaptation for sufficient photosynthesis of provitamin D in conditions of low intensity of UVB radiation in central and northern parts of Europe. |
Databáze: | OpenAIRE |
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