Vitamin A deficiency is associated with gastrointestinal and respiratory morbidity in school-age children.

Infection is an important cause of morbidity throughout childhood. Poor micronutrient status is a risk factor for infection-related morbidity in young children, but it is not clear whether these associations persist during school-age years. We examined the relation between blood concentrations of micronutrient status biomarkers and risk of gastrointestinal and respiratory morbidity in a prospective study of 2774 children aged 5-12 y from public schools in Bogotá, Colombia. Retinol, zinc, ferritin, mean corpuscular volume, hemoglobin, erythrocyte folate, and vitamin B-12 concentrations were measured in blood at enrollment into the cohort. Children were followed for 1 academic year for incidence of morbidity, including diarrhea with vomiting, cough with fever, earache or ear discharge with fever, and doctor visits. Compared with adequate vitamin A status (≥30.0 µg/dL), vitamin A deficiency (<10.0 µg/dL) was associated with increased risk of diarrhea with vomiting [unadjusted incidence rate ratio (IRR): 2.17; 95% CI: 0.95, 4.96; P-trend = 0.03] and cough with fever (unadjusted IRR: 2.36; 95% CI: 1.30, 4.31; P-trend = 0.05). After adjustment for several sociodemographic characteristics and hemoglobin concentrations, every 10 µg/dL plasma retinol was associated with 18% fewer days of diarrhea with vomiting (P < 0.001), 10% fewer days of cough with fever (P < 0.001), and 6% fewer doctor visits (P = 0.01). Every 1 g/dL of hemoglobin was related to 17% fewer days with ear infection symptoms (P < 0.001) and 5% fewer doctor visits (P = 0.009) after controlling for sociodemographic factors and retinol concentrations. Zinc, ferritin, mean corpuscular volume, erythrocyte folate, and vitamin B-12 status were not associated with morbidity or doctor visits. Vitamin A and hemoglobin concentrations were inversely related to rates of morbidity in school-age children. Whether vitamin A supplementation reduces the risk or severity of infection in children over 5 y of age needs to be determined.

An analysis of prosthodontic research productivity: geographic, economic, and collaborative perspective.

PURPOSE: This study evaluated the quantity of prosthodontic literature produced globally by continent in three prosthodontic journals over a 10-year period, 1998-2008. Prosthodontic research productivity relative to economic status of countries and collaboration among countries grouped by economic status was assessed. MATERIALS AND METHODS: Three peer-reviewed prosthodontic journals were used for the analysis of articles published in 1998, 2003, and 2008: The Journal of Prosthetic Dentistry, International Journal of Prosthodontics, and Journal of Prosthodontics. The country of every author listed for each included article was recorded. The number of articles published by each continent and each country was reported. Countries were grouped according to the World Bank economic classification system, and the number of articles published by each economic class was found. RESULTS: The majority of publications over the 10-year period were produced in Asia (Japan), Europe (Germany), and North America (USA). Productivity declined by 14.4% in high-income countries while it increased in upper middle-, lower middle-, and low-income countries. The majority of publications written by upper and lower middle- and low-income countries were independent works. Articles resulting from collaboration increased over time for all economic classes of countries. CONCLUSIONS: The origins of prosthodontic literature are becoming more geographically and economically diverse, with increased contributions from Africa, Asia, and South America, and middle- and low-income countries between 1998 and 2008. Collaboration between high-income countries and the other economic group countries increased over time.

Vitamin D deficiency associated with increased incidence of gastrointestinal and ear infections in school-age children.

BACKGROUND: Vitamin D deficiency (VDD) is highly prevalent among children worldwide. The effects of VDD include alterations of the immune response and increased risk of infection but little evidence exists in school-age children. We investigated the association of vitamin D status with morbidity in a prospective study of school-age children from Bogotá, Colombia. METHODS: We measured plasma 25-hydroxyvitamin D (25(OH)D) concentrations in a random sample of 475 children (mean ± standard deviation age: 8.9 ± 1.6 years) and followed them for an academic year. Caregivers were asked to record daily information on the incidence of morbidity episodes using pictorial diaries. Baseline vitamin D status was classified according to 25(OH)D concentrations as deficient (<50 nmol/L), insufficient (≥50 and <75 nmol/L) or sufficient (≥75 nmol/L). We used Poisson regression to estimate incidence rate ratios and 95% confidence intervals for days with diarrhea, vomiting, diarrhea with vomiting, cough with fever and earache or discharge with fever, comparing vitamin D-deficient with vitamin D-sufficient children. Estimates were adjusted for child's age, sex and household socioeconomic status. RESULTS: The prevalence of VDD was 10%; an additional 47% of children were vitamin D-insufficient. VDD was associated with increased rates of diarrhea with vomiting (adjusted incidence rate ratio: 2.05; 95% confidence interval: 1.19, 3.53) and earache/discharge with fever (adjusted incidence rate ratio: 2.36; 95% confidence interval: 1.26, 4.44). VDD was not significantly related to cough with fever. CONCLUSIONS: These results suggest that VDD is related to increased incidence of gastrointestinal and ear infections in school-age children. The effect of correcting VDD on reducing risk of these infections needs to be tested in supplementation trials.