Objective: This study aimed to review the literature about blood concentrations of selenium
associated with gestational age, feeding, supplementation and related clinical
features in preterm infants. Data sources: Systematic review in the following databases: MEDLINE, PubMed, Google academics,
SciELO. org, ScienceDirect (Elsevier) and CINAHL-Plus with Full Text (EBSCO).
Articles published up to January 2013 with the keywords "selenium deficiency",
"selenium supplementation", "neonates", "infants", "newborn" and "preterm infants"
were selected. Data synthesis: The studies reported that low blood selenium levels are associated with increased
risk of respiratory diseases. Preterm infants, especially with low birth weight,
presented lower selenium levels. Selenium deficiency has also been associated with
the use of oral infant formula, enteral and parenteral nutrition (with or without
selenium addition). The optimal dose and length of selenium supplementation is not
well-established, since they are based only on age group and selenium ingestion by
breastfed children. Furthermore, the clinical status of the infant affected by
conditions that may increase oxidative stress, and consequently, selenium
requirements is not taken into account. Conclusions: Prematurity and low birth weight can contribute to low blood selenium in
premature infants. Selenium supplementation seems to minimize or prevent clinical
complications caused by prematurity.
Lower plasma selenium levels have been detected since the start of the research and supplementation (2 µg/kg/day of selenous acid) was not to enough to approach the reference values.
BACKGROUND: Vitamin D deficiency is being recognized as a pandemic due to the volume of people affected by the deficiency and the number of illnesses generated or stimulated by the deficiency. There is a lack of consensus in the literature on what is considered vitamin D deficiency [25(OH)D]. OBJECTIVE: This review brings together the most common levels of 25(OH)D found in healthy schoolchildren and what is considered deficient. METHODS: This systematic review was based on the literature accessed from the electronic databases: MEDLINE, EMBASE, LILACS, SCOPUS and WEB OF SCIENCE. The following descriptors were used in English, Portuguese and Spanish: “Vitamin D”; “Vitamin D deficiency”; “Nutritional Supplements” as well as all their synonyms. The meta-analysis was performed considering the random model. Inclusion criteria: healthy children aged 6 to 12 years, studies that had vitamin D levels, defined vitamin D deficiency. RESULTS: Of the 191 potentially eligible articles, only six articles were included, with 2618 students in total. The mean value of 25(OH)D was estimated at 18.11 ng/mL with 95% confidence interval. Among the articles found, three were considered deficiency levels below 20 ng/mL, one considered below 18 ng/mL, another below 15 ng/mL, and the latter below 11 ng/ mL. The prevalence of vitamin D deficiency among the articles was 48.6%, 7%, 98%, 64.63%, 19.5%, 28.4%, according to each classification used by the same. CONCLUSION: The most common definition in the literature of 25(OH)D deficiency in schoolchildren was at levels below 20 ng/mL. No side effects have been reported in studies that used fortification and/or vitamin D supplementation. Daily supplementation is more effective than seasonal supplementation. However, more studies are needed to define what can be considered as optimal levels of 25(OH)D in children.
IntroductionEarly-life events are associated with the risk of obesity and comorbidities later in life. The gut microbiota—whose composition is influenced by genetics and environmental factors—could be involved. Since the microbiota affects metabolism and fat storage, early-life insults could contribute to the occurrence of obesity driven, in part, by microbiota composition. We examined associations of gut bacteria with early-life events, nutritional status, and body composition in the Nutritionist’s Health Study (NutriHS).MethodsA cross-sectional study of 114 female participants examining early-life data, body composition, and biological samples was conducted. Fecal microbiota structure was determined targeting the V4 region of the 16S rRNA gene. Principal coordinates analysis (PCoA) and permutational multivariate analysis of variance (PERMANOVA) were used to test the impact of variables on microbial diversity. Profiles were identified using the Jensen-Shannon divergence matrix and Calinski–Harabasz index. Differential abundance between the categories of exclusive breastfeeding duration and nutritional status was tested using DESeq2.ResultsIn the sample [median age 28 years and body mass index (BMI) 24.5 kg/m2], 2 microbiota profiles driven by the Blautia or Prevotella genus were identified. An estimated 9.1% of the variation was explained by the profiles (p < 0.001), 2.1% by nutritional status (p = 0.004), and 1.8% by exclusive breastfeeding (p = 0.012). The proportion of participants with BMI <25 kg/m2 and who were breastfed for at least 6 months was higher in the Blautia profile (p < 0.05).ConclusionFindings in a Blautia-driven profile of healthy women reinforce that early-life events play a role in defining gut microbiota composition, confirming the importance of exclusive breastfeeding for infant gut colonization in establishing a protective profile against adiposity-related outcomes in adulthood.
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