M S W Teigmo1, T E Gundersen2, N Emaus3, G Grimnes4. 1. Tromsø Endocrine Research Group, Department of Clinical Medicine, UiT The Arctic University of Norway, Tromsø, Norway. maina.wergeland@gmail.com. 2. Vitas AS, Oslo, Norway. 3. Department of Health and Care Sciences, UiT The Arctic University of Norway, Tromsø, Norway. 4. Tromsø Endocrine Research Group, Department of Clinical Medicine, UiT The Arctic University of Norway, Tromsø, Norway.
Abstract
BACKGROUND/ OBJECTIVES: Sufficient vitamin A levels are important for many functions-and both too little and too much may have detrimental health effects. The aim of the study was to describe the distribution of retinol levels in Norwegian adolescents, the relation between lifestyle factors and retinol levels, and the relation between retinol levels and bone mineral density (BMD). SUBJECTS/ METHODS: Serum retinol was measured in 414 girls and 474 boys aged 15-19 years, participating in the Tromsø Study: Fit Futures. Questionnaires regarding health and lifestyle factors were filled in, and physical examinations, body composition, and bone mineral density measurements (DEXA) performed. Multiple regression analyses were used to discover associations between retinol and exposure variables. RESULTS: Retinol levels ranged from 0.26 to 6.46 μmol/L with a median (2.5-97.5 percentile) of 2.35 (1.01-4.67) μmol/L. There was no gender difference. In the multivariate models, fat mass, albumin level, physical activity, and lunch habits were positively associated with retinol levels in boys. In girls, fat mass and height were negatively associated with retinol levels, and lean mass, vitamin D, calcium, total cholesterol, and the use of contraceptives were positively associated with retinol levels (p < 0.05). The models explained 18.3% and 14.6% of the variation (R2) in girls and boys, respectively. Retinol levels were not independently associated with BMD. CONCLUSION: Retinol levels in Norwegian adolescents are higher than reported elsewhere, and are to a low degree explained by lifestyle and physical measurements. No independent association with BMD was found.
BACKGROUND/ OBJECTIVES: Sufficient vitamin A levels are important for many functions-and both too little and too much may have detrimental health effects. The aim of the study was to describe the distribution of retinol levels in Norwegian adolescents, the relation between lifestyle factors and retinol levels, and the relation between retinol levels and bone mineral density (BMD). SUBJECTS/ METHODS: Serum retinol was measured in 414 girls and 474 boys aged 15-19 years, participating in the Tromsø Study: Fit Futures. Questionnaires regarding health and lifestyle factors were filled in, and physical examinations, body composition, and bone mineral density measurements (DEXA) performed. Multiple regression analyses were used to discover associations between retinol and exposure variables. RESULTS:Retinol levels ranged from 0.26 to 6.46 μmol/L with a median (2.5-97.5 percentile) of 2.35 (1.01-4.67) μmol/L. There was no gender difference. In the multivariate models, fat mass, albumin level, physical activity, and lunch habits were positively associated with retinol levels in boys. In girls, fat mass and height were negatively associated with retinol levels, and lean mass, vitamin D, calcium, total cholesterol, and the use of contraceptives were positively associated with retinol levels (p < 0.05). The models explained 18.3% and 14.6% of the variation (R2) in girls and boys, respectively. Retinol levels were not independently associated with BMD. CONCLUSION:Retinol levels in Norwegian adolescents are higher than reported elsewhere, and are to a low degree explained by lifestyle and physical measurements. No independent association with BMD was found.