著者

小林 正 康村 満枝 出海 裕子

出版者

公益社団法人 日本ビタミン学会

雑誌

ビタミン (ISSN:0006386X)

巻号頁・発行日

vol.49, no.9-10, pp.373-379, 1975-10-25 (Released:2018-03-06)

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In order to clarify the influences of sunlight intensity on the yield of vitamin D by sunlight irradiation of provitamin D, an ergosterol solution was irradiated by sunlight under various circumstances and the yield of vitamin D_2 in the solution was determined according to the procedure described in the previous paper^<1)>. The results are summarized in the following : (1) When the ergosterol solution was irradiated by sunlight of fine days at Kobe in different seasons, yearly variation of the yields showed that these in summer were significantly higher than those in winter and that these in spring or autumn were nearly middle between the two classes ; (2) When the ergosterol solution was irradiated by sunlight of different weather's days at a same place in a same month, the yields of fine days were significantly higher than those of cloudy, smogy and rainy days ; (3) When the ergosterol soltuion was irradiated by sunlight of nearly same weather's days at different places in a same month, there were no significant difference each other except the cases of Shiga heights and Kobe in summer ; (4) There were significant correlations between the yields and the sunlight intensities of both 300〜400 and 300〜330nm ranges, and the correlation with these in the latter's range was higher than those in the former's ; (5) There was no significant correlatation between the yields estimated on fine days and the sulfur dioxide concentrations in atmosphere.