Vitamin D dietary intake and status in a sample of adolescents

Abstract

Summary: Background & Aims: Vitamin D is an essential micronutrient in multiple cellular and physiological regulatory processes including related bone health. Several European surveys including children and adolescents have reported a low vitamin D intake and high prevalence of insufficient or even deficient vitamin D status. In Switzerland, no recent data are available. This study aimed to assess dietary intakes, status, and major dietary sources of vitamin D in a convenience sample of Swiss healthy adolescents. Methods: Adolescents aged between 11 and 18 years were recruited in the Lausanne region, Switzerland, between April and November 2017. Their diet was assessed using two 24-hour recalls. Vitamin D content of consumed foods was calculated using the Swiss Food Composition Database. Vitamin D levels were analyzed using high-performance liquid chromatography coupled with ultraviolet–visible spectroscopy. Results: In 29 adolescents, median [P25–P75] vitamin D intake was 0.9 [0.6–1.5] μg/day. This value reached less than 10% of recommended intake (15 μg/day). Median plasma 25(OH)D level was 56.9 [48.3–69.8] nmol/L. One-third of participants had therefore insufficient vitamin D status (≤50 nmol/L). Among adolescents tested in summer, 90% had a sufficient status. The main dietary sources of vitamin D were fish (35.2%) and dairy products (32.3%). Conclusion: In this small group of Swiss adolescents, vitamin D intake was below the recommendations. A sufficient vitamin D level seems attainable for the majority of adolescents in summer unlike for the fall to spring period. Further studies are necessary to validate these findings on a representative sample of children and adolescent at the national level.

Keywords

• Vitamin D
• Dietary intake
• Vitamin D status
• Dietary sources
• Adolescents
• Switzerland