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Additional file 1.

Additional file 1: Table A1. Sample size, skewness and p-values from a normality test for each of the partitions each corresponding to Table 2. Table A2. Methods used for estimating the lower and upper limits of the reference intervals provided in Table 2, where P, NP and R represent the parametric, non-parametric and robust methods. The methods are selected according to sample size and distributional investigations provided in Table A1. Table A3. Sample size, skewness and p-values from a normality test for each of the partitions each corresponding to Table 3. Table A4. Methods used for estimating the lower and upper limits of the reference intervals provided in Table 3, where P, NP and R represent the parametric, non-parametric and robust methods. The methods are selected according to sample size and distributional investigations provided in Table A3. Table A5. Sample size, skewness and p-values from the test of normality corresponding to partitions used in Table 4. Table A6. Methods used for estimating the lower and upper limits of the reference intervals provided in Table 4, where P, NP and R represent the parametric, non-parametric and robust methods. The methods are selected according to sample size and distributional investigations provided in Table A5. Table A7. Sample size for monthly age partitions for females and males.

Additional file 1: Supplemental Table 1. Linear GEE regression model for association between handheld screen time (h/day) and total cardiometabolic risk score and individuals risk factors, n = 1706. Supplemental Table 2. Linear GEE regression model for association between Non-handheld screen time (h/day) and total cardiometabolic risk score and individuals risk factors, n = 1706. Supplemental Table 3. Linear GEE regression model for association between screen time (h/day) and total cardiometabolic risk score and individuals risk factors, n = 1706.

Supplemental material, AUT756787_Lay_Abstract for Prospective cohort study of vitamin D and autism spectrum disorder diagnoses in early childhood by Yamna Ali, Laura N Anderson, Sharon Smile, Yang Chen, Cornelia M Borkhoff, Christine Koroshegyi, Gerald Lebovic, Patricia C Parkin, Catherine S Birken, Peter Szatmari and Jonathon L Maguire; on behalf of the TARGet Kids! Collaboration in Autism

ImportanceEpidemiological studies support a link between low 25-hydroxyvitamin D levels and a higher risk of viral upper respiratory tract infections. However, whether winter supplementation of vitamin D reduces the risk among children is unknown.ObjectiveTo determine whether high-dose vs standard-dose vitamin D supplementation reduces the incidence of wintertime upper respiratory tract infections in young children.Design, setting, and participantsA randomized clinical trial was conducted during the winter months between September 13, 2011, and June 30, 2015, among children aged 1 through 5 years enrolled in TARGet Kids!, a multisite primary care practice-based research network in Toronto, Ontario, Canada.InterventionsThree hundred forty-nine participants were randomized to receive 2000 IU/d of vitamin D oral supplementation (high-dose group) vs 354 participants who were randomized to receive 400 IU/d (standard-dose group) for a minimum of 4 months between September and May.Main outcome measuresThe primary outcome was the number of laboratory-confirmed viral upper respiratory tract infections based on parent-collected nasal swabs over the winter months. Secondary outcomes included the number of influenza infections, noninfluenza infections, parent-reported upper respiratory tract illnesses, time to first upper respiratory tract infection, and serum 25-hydroxyvitamin D levels at study termination.ResultsAmong 703 participants who were randomized (mean age, 2.7 years, 57.7% boys), 699 (99.4%) completed the trial. The mean number of laboratory-confirmed upper respiratory tract infections per child was 1.05 (95% CI, 0.91-1.19) for the high-dose group and 1.03 (95% CI, 0.90-1.16) for the standard-dose group, for a between-group difference of 0.02 (95% CI, -0.17 to 0.21) per child. There was no statistically significant difference in number of laboratory-confirmed infections between groups (incidence rate ratio [RR], 0.97; 95% CI, 0.80-1.16). There was also no significant difference in the median time to the first laboratory-confirmed infection: 3.95 months (95% CI, 3.02-5.95 months) for the high-dose group vs 3.29 months (95% CI, 2.66-4.14 months) for the standard-dose group, or number of parent-reported upper respiratory tract illnesses between groups (625 for high-dose vs 600 for standard-dose groups, incidence RR, 1.01; 95% CI, 0.88-1.16). At study termination, serum 25-hydroxyvitamin D levels were 48.7 ng/mL (95% CI, 46.9-50.5 ng/mL) in the high-dose group and 36.8 ng/mL (95% CI, 35.4-38.2 ng/mL) in the standard-dose group.Conclusions and relevanceAmong healthy children aged 1 to 5 years, daily administration of 2000 IU compared with 400 IU of vitamin D supplementation did not reduce overall wintertime upper respiratory tract infections. These findings do not support the routine use of high-dose vitamin D supplementation in children for the prevention of viral upper respiratory tract infections.Trial registrationclinicaltrials.gov Identifier: NCT01419262.

The objective of this study was to evaluate the association of vitamin D intake and serum levels with fracture risk in children under 6 years of age. A case-control study was conducted in Toronto, Ontario, Canada. Cases were recruited from the fracture clinic at the Hospital for Sick Children, and matched controls were obtained from the TARGet Kids! primary-care research network. Controls were matched to cases on age, sex, height, and season. Fracture risk was estimated from conditional logistic regression, with adjustment for skin type, fracture history, waist circumference, outdoor free play, neighborhood income, soda consumption, and child's birth weight. A total of 206 cases were recruited during May 2009–April 2013 and matched to 343 controls. Serum 25-hydroxyvitamin D concentration (per 10-nmol/L increment: adjusted odds ratio (aOR) = 0.95, 95% confidence interval (CI): 0.88, 1.03) and intake of cow's milk (2 cups/day vs. 2 cups/day: aOR = 1.39 (95% CI: 0.85, 2.23)) were not significantly associated with reduced odds of fracture. A statistically significant association was observed between child use of vitamin D supplements and decreased odds of fracture (yes vs. no: aOR = 0.42, 95% CI: 0.25, 0.69). Vitamin D supplementation, but not serum 25-hydroxyvitamin D level or milk intake, was associated with reduced fracture risk among these healthy young children.