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Thanks for taking the time write it all out, much appreciated. Do you know if the time of day makes a different? I avoid the Sun between 9am-3pm as that seems

by DenisM 6y ago

Thanks for taking the time write it all out, much appreciated. Do you know if the time of day makes a different? I avoid the Sun between 9am-3pm as that seems relatively easy to get sunburned during that time, but I wonder if the alleged benefits are tied to the same time window?

lhl 6y ago
Yes, time of day actually matters greatly since it depends on UVB exposure. Here's some classic research from 1988 discussing the topic: Webb, A. R., L. Kline, and M. F. Holick. “Influence of Season and Latitude on the Cutaneous Synthesis of Vitamin D3: Exposure to Winter Sunlight in Boston and Edmonton Will Not Promote Vitamin D3 Synthesis in Human Skin.” The Journal of Clinical Endocrinology and Metabolism 67, no. 2 (August 1988): 373–78. https://doi.org/10.1210/jcem-67-2-373 https://doi.org/10.1210/jcem-67-2-373. Also, here's a web calculator that can help you calculate UV exposure required to get a desired amount of Vitamin D (and to avoid a sunburn) based on location, time of year and day: https://fastrt.nilu.no/VitD_quartMEDandMED_v2.html https://fastrt.nilu.no/VitD_quartMEDandMED_v2.html