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

Birna Thorisdottir,Inga Thorsdottir,Ingibjorg Gunnarsdottir,Bryndis Birgisdottir,Laufey Steingrimsdottir,Gestur Palsson

doi:10.3390/nu8020075

Birna Thorisdottir, Inga Thorsdottir + Show 4 more

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https://doi.org/10.3390/nu8020075

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Journal: Nutrients	Publication Date: Feb 4, 2016
Citations: 59	License type: CC BY 4.0

Affiliation: National University Hospital of Iceland

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.

Highlights

Vitamin D sufficiency in childhood is associated with improved bone health [1] and may possibly lower the risk for type 1 diabetes [2], cardiovascular disease [3] and other diseases later in life [4].It may have short-term benefits beyond bone metabolism
25% having blood drawn during winter or spring were vitamin D sufficient, compared with 52% of children measured during autumn and 76% of children measured during summer (p < 0.001)
Our main finding was the tracking of vitamin D status during a 5-year period from 1 to 6 years of age, with a clear regression towards the mean

Summary

Introduction

Vitamin D sufficiency in childhood is associated with improved bone health [1] and may possibly lower the risk for type 1 diabetes [2], cardiovascular disease [3] and other diseases later in life [4]. It may have short-term benefits beyond bone metabolism. Iceland has a small and relatively genetically homogenous population [10] It is geographically located at 63–66 ̋ N, resulting in little or no cutaneous vitamin D synthesis during large parts of the year [11,12]. Use of cod liver oil or another form of vitamin D supplement is part of the Icelandic food based recommendations for all age groups [16]

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