Browsing by Author "Camargo Jr, Carlos A."

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    Vitamin D status and supplementation in Antarctica: a systematic review and meta- analysis
    (2021) Cabalin, Carolina; Iturriaga, Carolina; Perez Mateluna, Guillermo; Echeverria, Denise; Camargo Jr, Carlos A.; Borzutzky Schachter, Arturo
    Living at high latitudes is associated with vitamin D (VD) deficiency. An ideal setting to study this is the Antarctic continent, which has temporary inhabitants, but the magnitude of the effect of living in Antarctica and the effects of VD supplementation on this population remain unclear. We performed a systematic review and meta-analysis to assess the effect of temporary residence in Antarctica and impact of VD supplementation on VD status of this population. Random-effects meta-analyses were performed to assess serum 25-hydroxyvitamin D (25(OH)D) concentration changes after Antarctic residence (13 studies, 294 subjects) and after VD supplementation (5 studies, 213 subjects). Serum 25(OH)D mean difference after temporary residence in Antarctica was -15.0 nmol/L (95%CI: -25.9, -4.2; I-2=92%). Subgroup meta-analyses of studies evaluating Antarctic summer and winter stays showed 25(OH)D only decreases when overwintering (winter 25(OH)D change -17.0 nmol/L [95%CI: -24.1, -9.8; I-2=83%] vs. summer 25(OH)D change 1.3 nmol/L [95%CI: -14.6, 17.1; I-2=86%]). The meta-analysis of VD supplementation studies in Antarctica showed a mean 25(OH)D increase after supplementation of 10.8 nmol/L (95%CI: 3.3, 18.3; I-2=88%). In conclusion, VD status significantly worsens after inhabiting Antarctica, particularly when over-wintering. VD supplementation can prevent worsening of VD status and should be considered in this population.
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    Weekly Vitamin D Supplementation to Prevent Acute Respiratory Infections in Young Children at Different Latitudes: A Randomized Controlled Trial
    (2024) Reyes, Maria Loreto; Vizcaya, Cecilia; Le Roy, Catalina; Loureiro, Carolina; Brinkmann, Karin; Campos, Laura; Arancibia, Monica; Iturriaga, Carolina; Perez-Mateluna, Guillermo; Rojas-McKenzie, Maite; Dominguez, Gonzalo; Camargo Jr, Carlos A.; Borzutzky, Arturo
    Objective: To evaluate the effectiveness of weekly vitamin D supplementation in reducing the number of acute respiratory infections (ARI) in preschool children. Study design: Randomized, double-blind, placebo-controlled trial in 303 children aged 1.5-3.5 years from 2014 to 2105 in 3 Chilean cities at different latitudes: Santiago (33 degrees S, n = 101), Talcahuano (37 degrees S, n = 103), and Punta Arenas (53 degrees S, n = 99). Participants were allocated (1:1:1) to receive placebo, cholecalciferol (vitamin D3 (VD3)) 5600 IU/week (low-dose), or 11 200 IU/week (high-dose) for 6 months. Primary outcome was parent-reported number of ARI; secondary outcomes included number of ARI hospitalizations, change of serum 25-hydroxyvitamin D (25(OH)D) and LL-37/cathelicidin levels, and adverse events. Results: The mean age of participants was 26 +/- 6 months; 45% were female. Baseline 25(OH)D was 24.9 +/- 6.1 ng/ml, with 23% having 25(OH)D <20 ng/ml. No significant baseline clinical or laboratory differences were observed among groups. Overall, 64% (n = 194) completed study participation, without baseline differences between subjects lost to follow-up vs those completing participation or differences in completion rates across groups. After 6 months, a dose-dependent increase in serum 25(OH)D was observed from the VD3 intervention (P < .001), with a higher proportion of subjects ending the trial with 25(OH)D <20 ng/ml in the placebo group (30.8%) vs the low-dose (7.4%) and high-dose groups (5.1%). However, no group differences were observed in number of ARI (P = .85), ARI hospitalizations (P = .20), LL-37/cathelicidin change (P = .30), or adverse events (P = .41). Conclusions: While weekly VD3 supplementation, in doses equivalent to 800 IU and 1600 IU daily, was associated with improved 25(OH)D levels in preschoolers, we did not find a reduced number of ARI in this sample.