title: Neonatal Late-onset Hypocalcemia: Is There Any Relationship with Maternal Hypovitaminosis D?
abstract: OBJECTIVE
  Neonatal late-onset hypocalcemia is defined as hypocalcemia developed after postnatal 3 days and associated with hypoparathyroidism, high phosphate diets and vitamin D deficiency. We experienced the increment of neonatal late onset hypocalcemia over 1 year. We tried to evaluate the relationship between late onset hypocalcemia and maternal hypovitaminosis D.
  
  
  METHODS
  The medical records in the neonates with late-onset hypocalcemia during January 2007 to July 2008 were retrospectively reviewed. Among those patients, 17 paired sera of mothers and neonates had collected. The levels of 25-OH vitamin D (25OHD) and intact parathyroid hormone (iPTH) were measured and were compared with neonate and the mother.
  
  
  RESULTS
  The mean gestational age was 38(+1) weeks, and the mean body weight was 2,980 g. The onset time of hypocalcemia was 5.9 days of age. Most of them (88.2%) were feeding with formula and no one was only breast milk feeding. Of the 17 patients, 13 were born in spring or in winter. The median levels of calcium, phosphorus, alkaline phosphatase, iPTH and 25OHD were 7.0 mg/dL, 8.6 mg/dL, 191.0 U/L, 57.2 pg/mL and 24.0 ng/mL in neonates. The levels of 25OHD of 6 neonates were <20 ng/mL. A total of 16 mothers were considered vitamin D-deficient (<20 ng/mL), and vitamin D insufficient (20<25OHD<30 ng/mL).
  
  
  CONCLUSIONS
  Neonatal late-onset hypocalcemia in our study seems to be influenced by maternal vitamin D deficiency and insufficiency. Sun tanning and vitamin D supplements from winter to spring would be helpful to prevent maternal vitamin D deficiency, one of the causes of neonatal late-onset hypocalcemia.
authors.affiliation: Department of Pediatrics, Gyeongsang Institute of Health Science, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Hyun Jeong
authors.initials: HJ
authors.lastname: Do
authors.affiliation: Department of Pediatrics, Gyeongsang Institute of Health Science, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Ji Sook
authors.initials: JS
authors.lastname: Park
authors.affiliation: Department of Pediatrics, Gyeongsang Institute of Health Science, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Ji-Hyun
authors.initials: JH
authors.lastname: Seo
authors.affiliation: Department of Rehabilitation Medicine, Gyeongsang Institute of Health Science, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Eun Shin
authors.initials: ES
authors.lastname: Lee
authors.affiliation: Department of Pediatrics, Gyeongsang Institute of Health Science, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Chan-Hoo
authors.initials: CH
authors.lastname: Park
authors.affiliation: Department of Pediatrics, Gyeongsang Institute of Health Science, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Hyang-Ok
authors.initials: HO
authors.lastname: Woo
authors.affiliation: Department of Pediatrics, Gyeongsang Institute of Health Science, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Hee-Shang
authors.initials: HS
authors.lastname: Youn
keywords: Mother-newborn pair; Neonatal late-onset hypocalcemia; Vitamin D deficiency
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