日本新生児成育医学会雑誌　36(1)：121-126；2024　

日本新生児成育医学会雑誌　第36巻　第1号　121 ～ 126頁（2024年）

受付日：2023．04．04

受理日：2023．06．16

胃空腸吻合術後に発症し高用量の活性型ビタミンD 投与が効果的であったビタミンD 欠乏性くる病

High-dose Alfacalcidol for Treatment of Vitamin D Deficiency Rickets after Gastrojejunostomy

市立四日市病院　小児科

Department of Pediatrics, Yokkaichi Municipal Hospital

水谷茉莉・後藤盾信・笠井涼子・近藤優人・太田隆徳・周山めぐみ・後藤智紀・小出若登・牧　兼正・牛嶌克実・坂　京子

Mari MIZUTANI，Tatenobu GOTO，Ryoko KASAI，Yuto KONDO，Takanori OHTA，Megumi SUYAMA，Tomoki GOTO，Wakato KOIDE，Kanemasa MAKI，Katsumi USHIJIMA，Kyoko BAN

Key Words：rickets，vitamin D，duodenal atresia，gastrojejunostomy，malabsorption

ビタミンD は骨発育に必須の栄養素であり不足すると骨石灰化障害からくる病を発症する。症例は内臓逆位・十二 指腸閉鎖を認め日齢4 に胃空腸吻合術を行い生後3 か月にNICU を退院した男児。生後6 か月の定期受診時に低カ ルシウム（calcium：Ca）血症（5.6mg/dL），低リン（phosphorus：P）血症（3.0mg/dL），高アルカリホスファタ ーゼ（alkaline phosphatase：ALP）血症（3,322IU/L：日本臨床化学会［Japan Society of Clinical Chemistry：JSCC］ 法），副甲状腺ホルモン（intact-parathyroid hormone：intact-PTH）高値（282pg/mL），25 水酸化ビタミンD（25-hydroxy vitamin D：25（OH）D）低値（4ng/mL 未満）を認め骨X 線写真にて骨幹端不整像を認めたためビタミンD 欠乏性くる病と診断した。活性型ビタミンD（アルファカルシドール）補充療法を0.17μg/kg/day から開始した が血液検査所見と骨幹端不整像の改善を認めず徐々に1.3μg/kg/day まで増量し，生後1 歳3 か月でくる病所見が 改善した。胃空腸吻合術後にはビタミンD 吸収不全からのビタミンD 欠乏性くる病の発症に注意が必要である。

Rickets is classified into hypophosphatemic and hypocalcemic types, and bone calcification disorder caused by other factors. We report a case of a newborn male who was diagnosed with vitamin D deficiency rickets after gastrojejunostomy. The patient was delivered by cesarean section due to breech position at full term. Upper gastrointestinal（ UGI） contrast studies also suggested situs inversus and duodenal atresia. On day 4, he received gastrojejunostomy and was started on intravenous feeding and breastfeeding because of milk allergy. He was discharged from the hospital at 3 months after gastrojejunostomy. The 6th-month medical examination revealed serum calcium, 5.6mg/dL; phosphorus, 3.0mg/dL; alkaline phosphatase, 3,322IU/L; and 25 （OH） D under 4ng/mL. Radiographic images revealed cupping and fraying in both the lower ends of the radius and ulna bones. He was diagnosed with rickets caused by vitamin D deficiency, and treatment of alfacalcidol was initiated at 0.17μg/kg/day. However, no improvement in blood test results or bone stem irregularities was observed. The dose of alfacalcidol was gradually increased to 1.3μg/kg/day, and resulted in an amelioration of the clinical symptoms of rickets by the age of 1 year and 3 months. The occurrence of vitamin D deficiency rickets due to vitamin D malabsorption should be considered after gastrojejunostomy.