Ayabe Tadayuki, Yamamoto-Hanada Kiwako, Mezawa Hidetoshi, Konishi Mizuho, Ishitsuka Kazue, Saito Mayako, Fukami Maki, Michikawa Takehiro, Yamazaki Shin, Senju Ayako, Kusuhara Koichi, Kawamoto Toshihiro, Sanefuji Masafumi, Kato Kiyoko, Oda Masako, Mitsubuchi Hiroshi, Katoh Takahiko, Monden Yukifumi, Mise Nathan, Kayama Fujio, Saito Hirohisa, Ohya Yukihiro
Medical Support Center for Japan Environment and Children's Study, National Center for Child Health and Development, Tokyo, Japan.
Programme Office for Japan Environment and Children's Study, National Institute for Environmental Studies, Tsukuba, Japan.
Pediatr Int. 2018 Jan;60(1):30-34. doi: 10.1111/ped.13410. Epub 2017 Nov 24.
In recent years, a resurgence in the number of infants with vitamin D deficiency has been noted. In addition to seasonal differences in exposure to ultraviolet (UV) rays, regional differences in dietary habits and lifestyles may affect susceptibility to vitamin D deficiency. No studies have been conducted, however, on infants in multiple regions of Japan to determine the extent of differences in vitamin D status.
25-Hydroxyvitamin D (25OHD) was measured on radioimmunoassay in 126 infants aged 2-4 years, who participated in the Pilot Study of the Japan Environment and Children's Study (JECS) by the Ministry of Environment of Japan. A multiple regression model with 25OHD level as the outcome variable, and season and region as explanatory variables, was generated.
Both region and season during which infants participated in this study significantly affected 25OHD level (P = 0.0087 and <0.0001, respectively; Wald test). Reflecting decreased exposure to UV rays, infants who were examined in winter had lower 25OHD than those examined in summer. Infants from both Fukuoka Prefecture (33°N) and Kumamoto Prefecture (32°N), however, had lower 25OHD than those from Tochigi Prefecture (36°N), contrary to expectations given the extent of UV exposure.
Regional differences in daily habits and/or environmental factors affect 25OHD level in Japanese infants. The JECS is expected to identify those factors to provide guidance on preventing infantile vitamin D deficiency.
近年来，维生素D缺乏婴儿的数量有所回升。除了紫外线暴露的季节性差异外，饮食习惯和生活方式的地区差异可能会影响维生素D缺乏的易感性。然而，尚未对日本多个地区的婴儿进行研究以确定维生素D状态的差异程度。
对参与日本环境省日本环境与儿童研究（JECS）试点研究的126名2至4岁婴儿进行放射免疫测定，测量其25-羟基维生素D（25OHD）水平。建立以25OHD水平为结果变量，季节和地区为解释变量的多元回归模型。
婴儿参与本研究的地区和季节均对25OHD水平有显著影响（分别为P = 0.0087和<0.0001；Wald检验）。由于紫外线暴露减少，冬季接受检查的婴儿的25OHD水平低于夏季接受检查的婴儿。然而，与预期的紫外线暴露程度相反，福冈县（北纬33°）和熊本县（北纬32°）的婴儿的25OHD水平均低于栃木县（北纬36°）的婴儿。
日常习惯和/或环境因素的地区差异会影响日本婴儿的25OHD水平。预计JECS将确定这些因素，为预防婴儿维生素D缺乏提供指导。
