Vitamin D intake and cardiometabolic risk factors in adolescents.
BACKGROUND
A growing body of research suggests that vitamin D might play an important role in overall health. No data exist on vitamin D intake for the Azorean adolescent population. The purpose of this study was to assess vitamin D intake and investigate a possible association between vitamin D intake and cardiometabolic risk factors in Azorean adolescents.


METHODS
A cross-sectional school-based study was conducted on 496 adolescents (288 girls) aged 15-18 years from the Azorean Islands, Portugal. Anthropometric measurements (waist circumference and height), blood pressure (systolic), and plasma biomarkers [fasting glucose, insulin, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TGs)] were measured to assess metabolic risk. Homeostasis model assessment (HOMA), TC-to-HDL-C ratio, and waist-to-height ratio were calculated. For each of these variables, a Z-score was computed by age and sex. A metabolic risk score was constructed by summing the Z-scores of all individual risk factors. High risk was considered when the individual had ≥1 standard deviation (SD) of this score. Vitamin D intake was assessed with a semiquantitative food frequency questionnaire. Participants were classified into quartiles of vitamin D intake. Logistic regression was used to determine odds ratios for high cardiometabolic risk scores after adjusting for total energy intake, pubertal stage, fat mass percentage, and cardiorespiratory fitness.


RESULTS
Mean (SD) vitamin D intake was 5.8 (6.5) μg/day, and 9.1% of Azorean adolescents achieved the estimated average requirement of vitamin D (10 μg/day or 400 IU). Logistic regression showed that the odds ratio for a high cardiometabolic risk score was 3.35 [95% confidence interval (CI) 1.28-8.75] for adolescents in the lowest vitamin D intake quartile in comparison with those in the highest vitamin D intake quartile, even after adjustment for confounders.


CONCLUSIONS
A lower level of vitamin D intake was associated with worse metabolic profile among Azorean adolescents.
1 Research Centre in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto , Porto, Portugal .
Carla
C
Moreira
Pedro
P
Moreira
Sandra
S
Abreu
Paula C
PC
Santos
Isabel
I
Moreira-Silva
Susana
S
Póvoas
Jorge
J
Mota
Rute
R
Santos
D000293:Adolescent; D000886:Anthropometry; D001394:Azores / Q000453:epidemiology; D001794:Blood Pressure / Q000502:physiology; D002318:Cardiovascular Diseases / Q000453:epidemiology*; D004032:Diet; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008659:Metabolic Diseases / Q000453:epidemiology*; D009043:Motor Activity; D010809:Physical Fitness; D011627:Puberty / Q000502:physiology; D012307:Risk Factors; D012727:Sex Characteristics; D014807:Vitamin D / Q000008:administration & dosage*; D014815:Vitamins / Q000008:administration & dosage*
D014815:Vitamins; D014807:Vitamin D