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Regional differences in infant 25‐Hydroxyvitamin D: Pilot study of the Japan Environment and Children’s Study
Author(s) -
Ayabe Tadayuki,
YamamotoHanada 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
Publication year - 2018
Publication title -
pediatrics international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.49
H-Index - 63
eISSN - 1442-200X
pISSN - 1328-8067
DOI - 10.1111/ped.13410
Subject(s) - medicine , christian ministry , vitamin d and neurology , vitamin d deficiency , affect (linguistics) , pediatrics , demography , environmental health , philosophy , linguistics , theology , sociology
Background 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. Methods 25‐Hydroxyvitamin D (25 OHD ) 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 25 OHD level as the outcome variable, and season and region as explanatory variables, was generated. Results Both region and season during which infants participated in this study significantly affected 25 OHD level ( P = 0.0087 and <0.0001, respectively; Wald test). Reflecting decreased exposure to UV rays, infants who were examined in winter had lower 25 OHD than those examined in summer. Infants from both Fukuoka Prefecture (33°N) and Kumamoto Prefecture (32°N), however, had lower 25 OHD than those from Tochigi Prefecture (36°N), contrary to expectations given the extent of UV exposure. Conclusions Regional differences in daily habits and/or environmental factors affect 25 OHD level in Japanese infants. The JECS is expected to identify those factors to provide guidance on preventing infantile vitamin D deficiency.