Accurate determination of serum 3-epi-25-hydroxyvitamin D₃ in preterm infants and its relationship with gestational age

Kazumi Morisawa, Keio University School of Medicine, Nerima-ku, Tokyo, Japan; Kaori Hara-Isono, Keio University School of Medicine, Tokyo, Tokyo, Japan; Arimitsu Takeshi, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan; Hida Mariko, Saitama City Hospital, Saitama, Saitama, Japan; Kazushige Ikeda, Saitama City Hospital, Saitama City, Saitama, Japan; Shota Muramatsu, Keio University Hospital, Shinjuku-ku, Tokyo, Japan; Terumichi Nakagawa, Keio university hospital, Shinjuku-ku, Tokyo, Japan; Matsushita Hiromichi, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan; Hasegawa Tomonobu, Keio University, Nakano, Tokyo, Japan; Narumi Satoshi, Keio University, Tokyo, Tokyo, Japan