Vitamin D Intake and Status in 6-Year-Old Icelandic Children Followed up from Infancy

Nutrients. 2016 Feb 4;8(2):75. doi: 10.3390/nu8020075.

Abstract

High serum 25-hydroxyvitamin D (25(OH)D) levels have been observed in infants in Nordic countries, likely due to vitamin D supplement use. Internationally, little is known about tracking vitamin D status from infancy to childhood. Following up 1-year-old infants in our national longitudinal cohort, our aims were to study vitamin D intake and status in healthy 6-year-old Icelandic children (n = 139) and to track vitamin D status from one year of age. At six years, the mean 25(OH)D level was 56.5 nmol/L (SD 17.9) and 64% of children were vitamin D sufficient (25(OH)D ≥ 50 nmol/L). A logistic regression model adjusted for gender and breastfeeding showed that higher total vitamin D intake (Odds ratio (OR) = 1.27, 95% confidence interval (CI) = 1.08-1.49), blood samples collected in summer (OR = 8.88, 95% CI = 1.83-43.23) or autumn (OR = 5.64, 95% CI = 1.16-27.32) compared to winter/spring, and 25(OH)D at age one (OR = 1.02, 95% CI = 1.002-1.04) were independently associated with vitamin D sufficiency at age six. The correlation between 25(OH)D at age one and six was 0.34 (p = 0.003). Our findings suggest that vitamin D status in infancy, current vitamin D intake and season are predictors of vitamin D status in early school age children. Our finding of vitamin D status tracking from infancy to childhood provides motivation for further studies on tracking and its clinical significance.

Keywords: 25-hydroxyvitamin D; child; dietary supplements; seasons; tracking; vitamin D.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Child
  • Child Health*
  • Child, Preschool
  • Diet
  • Dietary Supplements
  • Female
  • Follow-Up Studies
  • Humans
  • Iceland / epidemiology
  • Infant
  • Infant Health*
  • Logistic Models
  • Male
  • Nutritional Status
  • Seasons*
  • Sunlight
  • Vitamin D Deficiency / blood
  • Vitamin D Deficiency / epidemiology*
  • Vitamin D* / administration & dosage
  • Vitamin D* / analogs & derivatives
  • Vitamin D* / blood
  • Vitamins* / administration & dosage
  • Vitamins* / blood

Substances

  • Vitamins
  • Vitamin D
  • 25-hydroxyvitamin D