Div Dermatology, Dept of Medicine, University of Tennessee Health Science Center, Memphis, TN 38104, United States.
J Steroid Biochem Mol Biol. 2010 Jul;121(1-2):331-3. doi: 10.1016/j.jsbmb.2010.04.003. Epub 2010 Apr 14.
While there is limited documentation that certain indoor tanning lamps effectively produce vitamin D, the diversity of such devices has not been extensively surveyed. This study compares the spectral effectiveness of a variety of tanning units, and solar spectra, for ultraviolet (UV) photosynthesis of pre-vitamin D3 (preD3) and UV induced erythema. Well-established techniques exist for the calculation of spectral effectiveness for photobiological responses that have defined action spectra. Using spectroradiometric data from sunlamp measurements, and standard solar reference spectra, we computed effective irradiances using the CIE action spectrum for the production of preD3 in human skin and the ISO/CIE human erythema reference action spectrum. We found, as with sunlight at different times or latitude, the preD3 and erythemal effectiveness of sunlamps varied as a function of the UV-B proportion of the spectrum. Ratios of sunlamp preD3 to erythemal effectiveness ranged from approximately 0.5 to nearly 2.0, similar to ratios for sunlight. Optimal risk to benefit conditions for preD3 from solar UV exposure occurs under high solar altitude, low zenith angle, midday midsummer sunlight. Analogous optimal preD3 exposure conditions are provided by low to intermediate pressure sunlamps with greater UV-B spectral overlap with the preD3 action spectrum. Similar to low altitude or high latitude sunlight, high pressure tanning units, filtered for negligible UV-B emissions, have insignificant vitamin D benefit. We conclude that while vitamin D can be made by both UVB exposure from indoor tanning units and by exposure UVB from sunlight, the effect is also comparably variable. Unlike sunlight, indoor tanning offers privacy and environmental conditions for practical full body exposure, lowering the requisite exposure per skin surface area, and device timers limit the potential of overexposure. Guidance for optimal use of tanning sources for vitamin D benefit is needed.
虽然有有限的文献证明某些室内晒黑灯能有效地产生维生素 D，但这些设备的多样性尚未得到广泛调查。本研究比较了各种晒黑装置和太阳光谱的光谱效果，以评估它们在预维生素 D3（preD3）的紫外线（UV）光合作用和 UV 诱导红斑方面的效果。对于具有定义作用光谱的光生物响应，已经存在用于计算光谱效果的成熟技术。我们使用来自太阳灯测量的分光辐射数据和标准太阳参考光谱，根据 CIE 作用光谱计算了在人体皮肤中产生 preD3 的有效辐照度以及 ISO/CIE 人类红斑参考作用光谱。我们发现，就像不同时间或纬度的阳光一样，太阳灯的 preD3 和红斑效果随光谱中 UV-B 的比例而变化。太阳灯的 preD3 与红斑效果的比值范围约为 0.5 到 2.0，与阳光的比值相似。从太阳紫外线暴露中获得 preD3 的最佳风险收益条件发生在高太阳高度、低天顶角、仲夏正午阳光下。类似的最佳 preD3 暴露条件由与 preD3 作用光谱具有较大 UV-B 光谱重叠的低到中等压力太阳灯提供。与低海拔或高纬度阳光类似，过滤掉可忽略不计的 UV-B 发射的高压晒黑装置几乎没有维生素 D 益处。我们得出的结论是，虽然维生素 D 可以通过室内晒黑装置的 UVB 暴露和阳光中的 UVB 暴露产生，但效果也同样具有变异性。与阳光不同，室内晒黑提供了隐私和环境条件，可实现全身实际暴露，降低了每单位皮肤面积所需的暴露量，并且设备定时器限制了过度暴露的可能性。需要为维生素 D 益处的最佳利用晒黑源提供指导。
