Vitamin D deficiency and associated factors among children in a tertiary care hospital setting: A retrospective cohort study

J Chin Med Assoc. 2025 Jun 1;88(6):433-441. doi: 10.1097/JCMA.0000000000001235. Epub 2025 Apr 8.

Abstract

Background: Vitamin D plays important roles in skeletal and extra-skeletal tissues. However, little is known about the vitamin D status in children in a hospital setting. We aimed to assess the vitamin D status, risk factors for vitamin D deficiency (VDD), and changes in biochemical profiles among children at a tertiary medical center in Taiwan.

Methods: This retrospective cohort study analyzed data from the Big Data Center of Taipei Veterans General Hospital. Children under 18-year-old who underwent 25-hydroxyvitamin D measurements between 2018 and 2023 were enrolled. Logistic regression analysis was performed to determine the risk factors for VDD.

Results: Among 1222 children enrolled, with a mean age of 8.5 ± 5.4 years, 597 (48.9%) had VDD. VDD was significantly associated with female sex (odds ratio [OR] = 1.624, 95% CI = 1.270-2.076), age >12 years (OR = 2.479, 95% CI = 1.584-3.881), vitamin D measurement during the spring/winter seasons (OR = 1.716, 95% CI = 1.340-2.197), and hospitalized children (OR = 1.949, 95% CI = 1.439-2.640). Age >1 to 6 years was a protective factor against VDD (OR = 0.391, 95% CI = 0.244-0.628). In addition, the OR of VDD was higher in those with an elevated intact parathyroid hormone level (OR = 8.667, 95% CI = 1.338-56.157).

Conclusion: Despite the high sun exposure in Taiwan, VDD is prevalent among children and adolescents. Physicians should be aware of VDD, especially in children who are female, aged >12 years, hospitalized, have increased intact parathyroid hormone levels, and during the spring/winter.

Keywords: Adolescent; Child; Vitamin D; Vitamin D deficiency.

MeSH terms

  • Adolescent
  • Child
  • Child, Preschool
  • Female
  • Humans
  • Infant
  • Logistic Models
  • Male
  • Parathyroid Hormone / blood
  • Retrospective Studies
  • Risk Factors
  • Seasons
  • Tertiary Care Centers
  • Vitamin D / analogs & derivatives
  • Vitamin D / blood
  • Vitamin D Deficiency* / epidemiology
  • Vitamin D Deficiency* / etiology

Substances

  • Vitamin D
  • 25-hydroxyvitamin D
  • Parathyroid Hormone