淺膚色

淺膚色是指一種顏色較白的膚色，擁有淺膚色的人黑色素較少，而且一般生活在紫外線較弱的地區，他們一般會被稱作白人。 ^[1][2][3]歐洲和東北亞的原住民的膚色較淺。 ^{[4][5][6][7][3][8]} 淺膚色人群起初都幾乎居住在遠離赤道的高緯度地區，這些地方的太陽光強度較低。 ^[9]

皮膚白皙的挪威人

1960年代，生物化學家W. Farnsworth Loomis發現，生活在高緯度的淺膚色人群能吸收更多的維生素D。淺色（菲茨派屈克度量 II 型）皮膚的人產生前維生素D₃的速度比深色皮膚（ V 型）的人要快5-10 倍。而一定量的維生素D有助於人體吸收更多的鈣。 ^{[10][11][12][13][14]}不過深膚色人群可以通過飲食來攝取維生素D，例如 ^[15][16]馴鹿的肉、內臟和脂肪都含有大量維生素D。 ^[17]

黑色素可以防止葉酸耗盡出現葉酸缺乏症以及DNA受損。^{[3][18][19][20]} 所以淺膚色人群如果居住在太陽光強度較高的赤道附近時，他們體內葉酸耗竭的風險會增加。如果葉酸耗盡的話，他們會面臨更高的DNA損傷、先天性障礙和罹患多種癌症（尤其是皮膚癌的風險。 ^[3]而且膚色特別淺的人容易出現雀斑。^[21][3]膚色非常淺的人（ I 型和II 型）在黑色素細胞中產生的黑色素非常少，並且在紫外線輻射的幾乎很難產生黑色素，^[22]所以這類人也容易曬傷，並且皮膚下的結締組織和去氧核糖核酸會被破壞，過早衰老（英語：Progeroid syndromes）和罹患皮膚癌。^[23][24] III-IV型膚色的人在受到紫外線輻射後就能產生黑色素。^[25][26]

隨着新航路開闢後各大洲人員流動日益頻繁，當今世界各地都有淺膚色人群。 ^[3][27]

蒙古國和滿洲的一些人皮膚也比較白皙

阿富汗和巴基斯坦境內的一些淺膚色人群

皮膚白皙的亞述人

參考文獻

1. light-skinned （頁面存檔備份，存於互聯網檔案館） Princeton University
2. Light-skinned. thefreedictionary.com. [24 January 2017]. （原始內容存檔於2020-04-23）.
3. Muehlenbein, Michael. Human Evolutionary Biology. Cambridge University Press. 2010: 192–213. 含有內容需登入查看的頁面 (link)
4. Relethford, John. Fundamentals of Biological Anthropology. Mayfield Publishing Company. 1997: 270 [2023-03-06]. ISBN 978-1559346672. （原始內容存檔於2020-05-11）.
5. Oxford Dictionaries. April 2010. Oxford University Press. "belonging to or denoting a human group having light-coloured skin" "white" (accessed 6 August 2012).
6. Dictionary.com: white （頁面存檔備份，存於互聯網檔案館） 3.a "marked by slight pigmentation of the skin"
7. Global Census. American Anthropological Association. [10 December 2012]. （原始內容存檔於14 September 2018）.
8. Kirchweger, Gina. The Biology of Skin Color: Black and White. Evolution Library. PBS. [22 September 2018]. （原始內容存檔於2013-02-16）.
9. Modern human variation: overview. （原始內容存檔於5 November 2012）.
10. Clements, T. L.; Adams, J. S.; Henderson, S. L.; Holick, M. F.; et al. Increased skin pigment reduces the capacity of skin to synthesize vitamin D (PDF). Lancet. 1982, 1 (8263): 74–76 [2023-03-06]. PMID 6119494. S2CID 41818974. doi:10.1016/S0140-6736(82)90214-8. （原始內容存檔 (PDF)於2020-04-29）.
11. Jablonski, N. G.; Chaplin, G. The evolution of human skin coloration. Journal of Human Evolution（英語：Journal of Human Evolution）. 2000, 39 (1): 57–106. PMID 10896812. doi:10.1006/jhev.2000.0403.
12. Webb, A. R. Who, what, where, and when: influences on cutaneous vitamin D synthesis. Progress in Biophysics and Molecular Biology. 2006, 92 (1): 17–25. PMID 16766240. doi:10.1016/j.pbiomolbio.2006.02.004 .
13. Armas, L. A.; Dowell, S.; Akhter, M.; Duthuluru, S.; Huerter, C.; Hollis, B. W.; Lund, R.; Heaney, R. P.; et al. Ultraviolet-B radiation increases serum 25-hydroxyvitamin D levels: The effect of UVB dose and skin color. Journal of the American Academy of Dermatology（英語：Journal of the American Academy of Dermatology）. 2007, 57 (4): 588–593. PMID 17637484. doi:10.1016/j.jaad.2007.03.004.
14. Chen, T. C.; et al. Factors that influence the cutaneous synthesis and dietary sources of vitamin D. Archives of Biochemistry and Biophysics. 2007, 460 (2): 213–217. PMC 2698590 . PMID 17254541. doi:10.1016/j.abb.2006.12.017.
15. Bjorn, L. O.; Wang, T; et al. Vitamin D in an ecological context. International Journal of Circumpolar Health（英語：International Journal of Circumpolar Health）. 2000, 59 (1): 26–32. PMID 10850004.
16. Van deer Meer; Boeke, A. J.; Lips, P.; Grootjans-Geerts, I.; Wuister, J. D.; Devillé, W. L.; Wielders, J. P.; Bouter, L. M.; Middelkoop, B. J.; et al. Fatty fish and supplement are the greatest modifiable contributors to the serum 25-hydroxyvitamin D concentration in a multiethnic population. Clinical Endocrinology. 2007, 68 (3): 466–472 [2023-03-06]. PMID 17941903. S2CID 15728496. doi:10.1111/j.1365-2265.2007.03066.x. hdl:1871/22170. （原始內容存檔於2020-05-01）.
17. Jablonski, Nina. Living Color. Berkeley, Los Angeles, London: University of California Press. 2012. ISBN 978-0-520-25153-3.
18. Vieth, Reinhold. Agarwal, Sabrina C; Stout, Sam D , 編. Effects of vitamin D on bone and natural selection of skin color: how much vitamin D nutrition are we talking about?. New York: Kluwer Academic/Plenum Press. 2003: 139–154. ISBN 978-1-4613-4708-8. doi:10.1007/978-1-4419-8891-1.
19. Hatchcock, J. N.; Shao, A.; Vieth, R.; Heaney, R.; et al. Risk assessment for vitamin D. American Journal of Clinical Nutrition（英語：American Journal of Clinical Nutrition）. 2007, 72 (1): 451–462. PMID 17209171. doi:10.1093/ajcn/85.1.6 .
20. Kimball, Samantha; Fuleihan, Ghada El-Hajj; Vieth, R; et al. Vitamin D: a growing perspective. Critical Reviews in Clinical Laboratory Sciences（英語：Critical Reviews in Clinical Laboratory Sciences）. 2008, 45 (4): 339–414. PMID 18568854. S2CID 57808076. doi:10.1080/10408360802165295.
21. Rhodes, A. R.; et al. Sun-induced freckles in children and young adults: a correlation of clinical and histopathologic features. Cancer (journal)（英語：Cancer (journal)）. 1991, 67 (7): 1990–2001. PMID 2004316. doi:10.1002/1097-0142(19910401)67:7<1990::aid-cncr2820670728>3.0.co;2-p .
22. Fitzpatrick, T. B.; Ortonne, J. P. Normal skin color and general considerations of pigmentary disorders. In Fitzpatrick's Dermatology in General Medicine. 2003, 6: 819–825.
23. Cleaver, J. E.; Crowely, E. UV damage, DNA repair and skin carcinogenesis. Frontiers in Bioscience. 2002, 7 (1–3): 1024–1043. PMID 11897551. doi:10.2741/cleaver .
24. Matsumura, Yasuhiro; Ananthawamy, Honnavara N. Toxic effects of ultraviolet radiation in the skin. Toxicology and Applied Pharmacology（英語：Toxicology and Applied Pharmacology）. 2004, 195 (3): 298–308. PMID 15020192. doi:10.1016/j.taap.2003.08.019.
25. Tadokoro, T.; et al. Mechanisms of skin tanning in different racial/ethnic groups in response to ultraviolet radiation. Journal of Investigative Dermatology. 2005, 124 (6): 1326–1332. PMID 15955111. doi:10.1111/j.0022-202X.2005.23760.x .
26. Nielsen, K.P.; et al. The importance of the depth distribution of melanin in skin for DNA protection and other photobiological processes. Journal of Photochemistry and Photobiology B: Biology. 2006a, 82 (3): 194–198. PMID 16388960. doi:10.1016/j.jphotobiol.2005.11.008.
27. O'Neil, Dennis. Skin Color Adaptation. Human Biological Adaptability: Skin Color as an Adaptation. Palomar. [10 December 2012]. （原始內容存檔於18 December 2012）.