Department of Dermatology D92, Bispebjerg Hospital, University of Copenhagen, Nielsine Nielsens Vej 17, 2400, Copenhagen NV, Denmark.
Photochem Photobiol Sci. 2021 Dec;20(12):1573-1584. doi: 10.1007/s43630-021-00115-w. Epub 2021 Oct 31.
Low 25-hydroxyvitamin D (25(OH)D) among dark-pigmented persons has been observed. To elucidate the reason for this we examined sun behaviour, sun-exposed body area, solar UVR exposure and 25(OH)D levels in immigrants with dark pigmented skin and Danes with light pigmented skin. Clothing, sun behaviour, and diet were recorded daily during a Danish summer season (93 analysed days). Erythema-weighted UVR doses were measured by personal electronic UVR dosimeters (with erythema response, measurement every 5th second) and 25(OH)D was measured in 72 participants (33 dark-skinned and 39 light-skinned). The immigrants exposed 28% less skin area, received 70% less UVR dose, and had 71% less 25(OH)D increase during the summer. The UVR reactivity (Δ25(OH)D per joule accumulated UVR dose) was similar (P = 0.62) among the immigrants (0.53 nmol l J) and the Danes (0.63 nmol l J). In the groups combined, 25(OH)D levels after summer were mainly influenced by UVR dose to exposed skin (28.8%) and 25(OH)D start level (27.9%). Height and measured constitutive skin pigmentation were of minor influence: 3.5% and 3.2%, respectively. Sun exposure and clothing habits were the main reasons for lower 25(OH)D level after summer in the darker immigrants, as both groups had similar UVR reactivity.
在深色皮肤的人群中观察到低 25-羟维生素 D（25(OH)D）的情况。为了阐明原因，我们检查了移民和丹麦人（浅色皮肤）的阳光行为、暴露的身体部位、太阳紫外线辐射暴露和 25(OH)D 水平。在丹麦夏季期间（93 个分析日），每天记录服装、阳光行为和饮食。通过个人电子紫外线辐射剂量计（具有红斑反应，每 5 秒测量一次）测量红斑加权紫外线辐射剂量，并对 72 名参与者（33 名深色皮肤和 39 名浅色皮肤）测量 25(OH)D。移民暴露的皮肤面积减少 28%，接受的紫外线辐射剂量减少 70%，夏季 25(OH)D 增加减少 71%。紫外线辐射反应性（每焦耳累积紫外线辐射剂量的 25(OH)D 增加量）在移民（0.53 nmol l J）和丹麦人（0.63 nmol l J）之间相似（P=0.62）。在两组合并中，夏季后 25(OH)D 水平主要受暴露皮肤的紫外线辐射剂量（28.8%）和 25(OH)D 起始水平（27.9%）影响。身高和测量的固有皮肤色素沉着的影响较小：分别为 3.5%和 3.2%。阳光照射和穿着习惯是较深肤色移民夏季后 25(OH)D 水平较低的主要原因，因为两组的紫外线辐射反应性相似。
