Nutritional rickets in Taiwanese children: Experiences at a single center

J Formos Med Assoc. 2018 Jul;117(7):583-587. doi: 10.1016/j.jfma.2017.08.013. Epub 2017 Sep 22.

Abstract

Background/purpose: The number of children with nutritional rickets in Taiwan has increased over the last decade. The aim of this study was to present our experiences in the management of patients with this condition.

Patients and methods: From 2011 to 2016, 10 children (3 boys and 7 girls) with nutritional rickets were enrolled in this study. Their clinical and biochemical data were analyzed.

Results: The median age of the 10 patients was 21 months (range, 12-25 months). The predisposing factors included exclusive breastfeeding, dietary restriction, and limited outdoor activities. The most common presentations were unsteady gait and bowlegs, and two patients had hypocalcemic seizures. All patients had elevated alkaline phosphatase levels (median, 1008 U/L; range, 484-2051 U/L), elevated serum intact parathyroid hormone levels (median, 333.8 pg/mL; range, 130-817 pg/mL), and hypophosphatemia (median, 3.0 mg/dL; range, 2.4-3.9 mg/dL). The median serum 25-hydroxyvitamin D level was 7.44 ng/mL (range, 1.44-9.82 ng/mL). After vitamin D supplementation was initiated, serum phosphorus levels normalized within 1 month, and serum intact parathyroid hormone levels returned to the normal range within 2 months. Six of the 10 patients had serum alkaline phosphatase levels close to the normal range within 3 months. All 10 patients exhibited complete bone healing within 6 months of vitamin D treatment.

Conclusion: Nutritional rickets is not as rare in Taiwan as previously thought. When physicians encounter infants or toddlers with typical bone deformities or hypocalcemic seizures, a high index of suspicion and a detailed nutritional history are important for early diagnosis and treatment.

Keywords: 25-Hydroxyvitamin D; Nutritional rickets; Rickets; Vitamin D deficiency.

MeSH terms

  • Alkaline Phosphatase / blood
  • Breast Feeding
  • Child, Preschool
  • Dietary Supplements
  • Female
  • Humans
  • Infant
  • Male
  • Parathyroid Hormone / blood
  • Radiography
  • Rickets / blood*
  • Rickets / etiology*
  • Taiwan
  • Vitamin D / analogs & derivatives
  • Vitamin D / blood
  • Vitamin D / therapeutic use
  • Vitamin D Deficiency / complications*
  • Vitamin D Deficiency / drug therapy*

Substances

  • Parathyroid Hormone
  • Vitamin D
  • 25-hydroxyvitamin D
  • Alkaline Phosphatase