Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove, QLD, Australia and Population Health Department, QIMR Berghofer Medical Research Institute, Herston, QLD, Australia.
Population Health Department, QIMR Berghofer Medical Research Institute, Herston, QLD, Australia.
Photochem Photobiol Sci. 2018 May 16;17(5):570-577. doi: 10.1039/c7pp00378a.
Sunlight generates vitamin D, but there are scant human data from randomised trials on which to base health policy advice about how much sun exposure is necessary to change 25(OH)D concentrations. The purpose of the study was to evaluate the feasibility of using solar ultraviolet (UV) radiation exposure to generate a change in 25(OH)D concentration in a randomised controlled trial (RCT). The intervention tested in this RCT was supervised exposure to one standard erythemal dose (SED; 100 J m-2) of solar UV radiation three days per week for three weeks with approximately 35% of the body surface area not covered by clothing. Thirty-six fair-skinned (skin type II and III) indoor workers from Brisbane, Australia were randomised into either the intervention group (n = 16) or the control group (n = 20); the latter did not receive any supervised sun exposure. We asked both groups to use sunscreen and to minimise time outdoors during the study period. We collected blood samples at baseline, once per week during the three week intervention period, and four weeks after the intervention finished. The cumulative UV radiation exposure over the intervention period measured using polysulphone badges was higher in the intervention group than in the control group (median 8 vs. 4 SEDs, p = 0.14). After three weeks, the mean serum 25(OH)D concentration increased from 60 to 65 nmol l-1 in the intervention group and from 55 to 57 nmol l-1 in the control group. After adjustment for baseline 25(OH)D, the mean change per week during the intervention phase was non-significantly higher in the intervention than in the control group (0.7 vs. 0.3; p = 0.35). This difference was not sustained during the follow-up period. Large field trials are needed to inform policy about how much natural sun exposure is required to raise 25(OH)D concentrations. This pilot identified key issues that need to be considered in the design of such a trial.
阳光可生成维生素 D，但随机试验中关于人类需要多少日照暴露量才能改变 25（OH）D 浓度的数据很少，因此，尚无法据此制定有关健康政策的建议。本研究旨在评估使用太阳紫外线（UV）辐射暴露来改变 25（OH）D 浓度的随机对照试验（RCT）的可行性。本 RCT 中测试的干预措施是每周接受三次，每次接受一标准红斑剂量（SED；100 J m-2）的太阳 UV 辐射，共三周，大约 35%的身体表面积未被衣物覆盖。36 名来自澳大利亚布里斯班的浅色皮肤（皮肤类型 II 和 III）室内工作者被随机分为干预组（n = 16）或对照组（n = 20）；后者未接受任何监督的阳光暴露。我们要求两组都使用防晒霜，并在研究期间尽量减少户外活动时间。我们在基线时、干预期的每周一次和干预结束后四周采集血液样本。使用聚砜徽章测量的干预期间的累积紫外线辐射暴露量，干预组高于对照组（中位数 8 与 4 SED，p = 0.14）。干预三周后，干预组的平均血清 25（OH）D 浓度从 60 增加到 65 nmol l-1，对照组从 55 增加到 57 nmol l-1。在调整基线 25（OH）D 后，干预期间每周的平均变化在干预组中高于对照组（0.7 与 0.3；p = 0.35）。但这种差异在随访期间并未持续。需要开展大型现场试验，为有关需要多少自然阳光暴露才能提高 25（OH）D 浓度的政策提供信息。本研究为该试验的设计确定了需要考虑的关键问题。
