Prevalence and predictors of vitamin D insufficiency in Brazilian children under 5 years of age: Brazilian National Survey on Child Nutrition (ENANI-2019).

To analyse the association of socio-demographic and health factors with vitamin D insufficiency and 25-hydroxyvitamin D (25(OH)D) concentration in Brazilian children aged 6-59 months. Data from 8145 children from the Brazilian National Survey on Child Nutrition (ENANI-2019) were analysed. The serum concentration of 25(OHD)D was measured using a chemiluminescent immunoassay. The prevalence of vitamin D insufficiency (25(OH)D < 50 nmol/l) and 95 % CI was calculated. Logistic and linear regression models were used to identify the variables associated with vitamin D insufficiency and serum 25(OH)D concentrations, respectively. The mean 25(OH)D concentration was 98·6 ± 36·0 nmol/l, and 4·3 % of the children presented vitamin D insufficiency. Children aged 6-23 months (OR = 2·23; 95 % CI 1·52, 3·26); belonging to Southeast (OR = 5·55; 95 % CI 2·34, 13·17) and South (OR = 4·57; 95 % CI 1·77, 11·84) regions; the second tertile of the National Wealth Score (OR = 2·14; 95 % CI 1·16, 3·91) and winter (OR = 5·82; 95 % CI 2·67, 12·71) and spring (OR = 4·84; 95 % CI 2·17, 10·80) seasons of blood collection were associated with a higher chance of vitamin D insufficiency. Female sex (ß = -5·66, 95 % CI - 7·81, -3·51), urban location (ß = -14·19, 95 % CI -21·0, -7·22) and no vitamin D supplement use (ß = -6·01, 95 % CI -9·64, -2·39) were inversely associated with serum 25(OH)D concentration. The age of children and the Brazilian geographical region of household location were the main predictors of vitamin D insufficiency. In Brazil, vitamin D insufficiency among children aged 6-59 months is low and is not a relevant public health problem.

Leptin gene polymorphism (rs7799039; G2548A) is associated with changes in serum lipid concentrations during pregnancy: a prospective cohort study.

PURPOSE: Little is known about the effects of leptin and leptin receptor polymorphisms on lipid changes during pregnancy. The aims of this study were to evaluate the associations between the single nucleotide polymorphisms (SNPs) of leptin and leptin receptor genes and the lipid concentrations during pregnancy; and to test whether dietary intake is a mediator in these associations. METHODS: A prospective cohort of 154 pregnant women was followed up in Rio de Janeiro, Brazil during the following gestational periods: 5-13th, 20-26th and 30-36th weeks. HDL-C, total cholesterol (TC) and triglyceride (TG) were measured by the enzymatic colorimetric method, and LDL-C was calculated. DNA was extracted by the phenol-chloroform method, and leptin (G2548A, rs7799039) and leptin receptor SNPs (Q223R; rs1137101 and K109R; rs1137100) were genotyped using real-time PCR. Statistical analyses included linear mixed-effect models. RESULTS: Women with the AA genotype of G2548A polymorphism reported a higher fat and total energy intake and had a higher increase in TG concentration during pregnancy than women with AG or GG genotype. The association between G2548A SNP and TG concentrations was not attenuated by adjusting for total lipid (g) and energy (kcal) intake. We did not observe significant associations between the Q223R and K109R SNPs and the lipid concentrations. CONCLUSIONS: Women homozygous for the A allele of the leptin SNP (G2548A) had a higher increase in TG concentrations per gestational week compared with women with the AG or GG genotype. This is an exploratory and hypothesis-generating study, and the results need confirmation in studies with larger sample sizes.'

Longitudinal association of 25-hydroxyvitamin D with adipokines and markers of glucose metabolism among Brazilian pregnant women.

This study aimed to evaluate the longitudinal association of vitamin D status with glycaemia, insulin, homoeostatic model assessment of insulin resistance, adiponectin and leptin. A prospective cohort with 181 healthy, pregnant Brazilian women was followed at the 5th-13th, 20th-26th and 30th-36th gestational weeks. In this cohort, 25-hydroxyvitamin D (25(OH)D) plasma concentrations were analysed using liquid chromatography-tandem MS. Vitamin D status was categorised as sufficient or insufficient using the Endocrine Society Practice Guidelines (≥75/<75 nmol/l) and the Institute of Medicine (≥50/<50 nmol/l) thresholds. Linear mixed-effect regression models were employed to evaluate the association between vitamin D status and each outcome, considering interaction terms between vitamin D status and gestational age (P<0·1). At baseline, 70·7 % of pregnant women had 25(OH)D levels <75 nmol/l and 16 % had levels <50 nmol/l. Women with sufficient vitamin D status at baseline, using both thresholds, presented lower glycaemia than those with insufficient 25(OH)D. Pregnant women with 25(OH)D concentrations <75 nmol/l showed lower insulin (ß=-0·12; 95 % CI -0·251, 0·009; P=0·069) and adiponectin (ß=-0·070; 95 % CI -0·150, 0·010; P=0·085) concentrations throughout pregnancy than those with 25(OH)D levels ≥75 nmol/l. Pregnant women with 25(OH)D <50 nmol/l at baseline presented significantly higher leptin concentrations than those with 25(OH)D levels ≥50 nmol/l (ß=-0·253; 95 % CI -0·044, 0·550; P=0·095). The baseline status of vitamin D influences the biomarkers involved in glucose metabolism. Vitamin D-sufficient women at baseline had higher increases in insulin and adiponectin changes throughout gestation than those who were insufficient.

Dietary intake variations from pre-conception to gestational period according to the degree of industrial processing: A Brazilian cohort.

OBJECTIVE: To estimate food intake changes from pre-conception to gestational period according to the degree of food processing. METHODS: Prospective cohort conducted in a public health care center in Rio de Janeiro with Brazilian pregnant women (n = 189). A food frequency questionnaire was applied at the first (5(th)-13(th)) and third (30(th)-36(th)) gestational trimesters. The food items were classified according to characteristics of food processing in four groups: unprocessed/minimally processed foods; sugar/fat; processed foods and ultra-processed foods. The variation of food intake according to the degree of processing between the pre-conception and gestational period was compared using paired Student's t-test. Linear regression models were performed to estimate the association of mother's characteristics on the variation of food group contribution to the total energy intake between periods. RESULTS: Total energy intake was 2415 (SD = 813) in the pre-conception and 2379 (750) kcal in the gestational period. We excluded women who had implausible total energy intake (<600 and >6000 kcal/day). The contribution of unprocessed/minimally processed food group to total energy intake during pregnancy when compared to the pre-conception period was higher [50.5 (14.1) vs. 48.8 (12.4), p-value = 0.048], while the caloric share of ultra-processed food group was lower [41.3 (14.6) vs. 43.1 (12.5), p-value = 0.032]. We observed a negative association of age (p-value = 0.009) and a positive association of pre-pregnancy BMI (p-value = 0.060) with the variation of ultra-processed food intake. CONCLUSIONS: Ultra-processed food intake decreased, while minimally/unprocessed food intake slightly increased from the pre-conception to gestational period. These results indicate potential for a larger improvement in the women's diet quality and that nutritional counseling interventions in pregnant women are still needed.

Association of pre-pregnancy maternal overweight/obesity and dietary intake during pregnancy with the concentrations of persistent organic pollutants in the human milk of women from Rio de Janeiro, Brazil.

Persistent organic pollutants (POPs) are toxic chemical compounds that can bioaccumulate, adhere to lipid matrices, and affect human health. This study aimed to investigate the association between maternal pre-pregnancy overweight/obesity and dietary intake during pregnancy and POP concentrations in the human milk of women from Rio de Janeiro, Brazil. One hundred and forty-seven women were followed from the third trimester of pregnancy until 119 days postpartum, and 77 human milk samples were analyzed between 2 and 119 days postpartum. POP concentrations were analyzed using gas chromatography-triple quadrupole mass spectrometry. Pregnancy dietary intake was estimated using a semi-quantitative food frequency questionnaire, and pre-pregnancy body mass index at baseline was classified as normal or overweight/obesity. Multiple logistic and linear regression models were performed to investigate the association between pre-pregnancy overweight/obesity, dietary intake during pregnancy, and POP concentrations in human milk. The models were adjusted for maternal age, maternal schooling, total cholesterol serum concentrations, and time postpartum. The analyses were corrected for multiple comparisons using the Benjamini-Hochberg test. Significant associations were observed between pre-pregnancy overweight/obesity and dichlorodiphenyldichloroethane (ppDDE), polychlorinated biphenyl (PCB)74, PCB138, PCB153, PCB170, PCB180, total PCBs, total 4PCBs, total 2 organochlorine pesticides (OCPs), and total POP concentrations. Higher daily lipid intake during pregnancy increased human milk hexachlorobenzene (HCB). This study showed that pre-pregnancy overweight/obesity and total lipid intake during pregnancy were associated with POP concentrations in the milk of women from Rio de Janeiro, Brazil. To promote adequate nutritional status since preconception and surveillance and control of POP in the environment could be essential to ensure binomial mother-infant health and biomonitoring studies and programs for these POPs should be stimulated.

Association between persistent organic pollutants in human milk and the infant growth and development throughout the first year postpartum in a cohort from Rio de Janeiro, Brazil.

Persistent organic pollutants (POPs) are compounds that are recalcitrant and ubiquitous that bioaccumulate in human milk (HM) and can impact infant growth and development. We explore the association between POP concentration in HM at 2-50 days postpartum and infant growth and development trajectory throughout the first year of life. A cohort of 68 healthy adult Brazilian women and their infants were followed from 28 to 35 gestational weeks to 12 months postpartum. HM samples were collected between 2 and 50 days postpartum, and POP concentrations were analyzed using gas chromatography with mass spectrometry. Concentrations of POPs >limit of quantification (LOQ) were defined as presence, and concentrations ≤LOQ as an absence. Growth z-scores were analyzed according to WHO growth charts and infant development scores according to Age & Stages Questionnaires at 1 (n = 66), 6 (n = 50), and 12 months (n = 45). Linear mixed effects (LME) models were used to investigate the association of POPs in HM with infant growth and development. Benjamini-Hochberg (BH) correction for multiple testing was performed to reduce the false discovery ratio. P < 0.1 was considered for models with the interaction between POPs and time/sex. After BH correction, adjusted LME models with time interaction showed (1) a positive association between the presence of ß hexachlorocyclohexane and an increase in head circumference-for-age z-score (ß = 0.003, P = 0.095); (2) negative associations between total POPs (ß = -0.000002, P = 0.10), total organochlorine pesticides (ß = -0.000002, P = 0.10), and dichlorodiphenyldichloroethylene concentrations in HM (ß = -0.000002, P = 0.10) and fine motor scores. No statistical difference between the sexes was observed. Postnatal exposure to organochlorine pesticides in HM shows a positive association with the trajectory of head circumference-for-age z-score and a negative association with the trajectories of fine motor skills scores. Future studies on POP variation in HM at different postpartum times and their effect on infant growth and development should be encouraged.

Characterization of micronutrient supplements use by Brazilian children 6-59 months of age: Brazilian National Survey on Child Nutrition (ENANI-2019).

This study aimed to characterize micronutrient supplements use among Brazilian children 6-59 months of age included in the Brazilian National Survey on Child Nutrition (ENANI-2019; n = 12,598). Micronutrient supplements use at the time of the interview and the 6 months prior to it was evaluated using a structured questionnaire. The following indicators were included: micronutrient supplement use; supplements containing a single micronutrient; supplements of the Brazilian National Iron Supplementation Program (PNSF); multivitamin supplements with or without minerals; multivitamin supplements with minerals; multivitamin supplements without minerals. The estimates and their respective 95% confidence intervals (95%CI) were calculated for Brazil and according to macroregion, educational level of the mother or caregiver, and type of health care service used, considering the sampling plan, weights, and calibration. In Brazil, the prevalence of micronutrient supplements use was 54.2% (95%CI: 50.5; 57.8), with the highest prevalence in the North Region (80.2%; 95%CI: 74.9; 85.6) and among children 6-23 months of age (69.5%; 95%CI: 65.7; 73.3). The prevalence of the use of supplements containing exclusively iron and exclusively vitamin A in Brazil was 14.6% (95%CI: 13.1; 16.1) and 23.3% (95%CI: 19.4; 27.1), respectively. The prevalence of the use of multivitamin with or without minerals in Brazilian children 6-59 months of age was 24.3% (95%CI: 21.4; 27.2). These results may help to understand the practice of supplements use among Brazilian children and support the proposal of national public policies for the prevention and control of micronutrient deficiencies.

Trends of height-for-age Z-scores according to age among Brazilian children under 5 years old from 2006 to 2019.

This study compared the distribution of stunting and height-for-age (HAZ) Z-scores among age groups in data from the Brazilian National Survey on Demography and Health of Women and Children (PNDS 2006) and the Brazilian National Survey on Child Nutrition (ENANI-2019). The final sample comprised 4,408 and 14,553 children < 59 months of age in the PNDS 2006 and ENANI-2019, respectively. Children with HAZ scores < -2 according to the World Health Organization (WHO) growth standard were classified as stunted. Prevalence, 95% confidence intervals (95%CI), means, and standard deviations were estimated for Brazil and according to age. The distribution of HAZ scores at each age (in months) was estimated using the svysmooth function of the R survey package. Analyses considered the complex sampling design of the studies. Statistical differences were determined by analyzing the 95%CI of the overlap of point estimates. From 2006 to 2019, the prevalence of stunting for children < 12 months of age increased from 4.7% to 9%. As expected, the smoothed curves showed a higher mean HAZ score for children < 24 months of age in 2006 than in 2019 with no overlap of 95%CI among children aged 6-12 months. For children ≥ 24 months of age, we observed a higher mean HAZ score in 2019. Although the prevalence of stunting among children < 59 months of age was similar between 2006 and 2019, mean HAZ scores among children ≥ 24 months of age increased, whereas the mean HAZ score among children < 24 months of age decreased. Considering the deterioration in living conditions and the potential impact of the COVID-19 pandemic, we expect a greater prevalence of stunting in Brazil in the near future.

The National Wealth Score in the Brazilian National Survey on Child Nutrition (ENANI-2019).

The National Wealth Score (IEN) is a synthetic household index that assesses socioeconomic conditions. This study aims to present the methods used to update the IEN using data from the Brazilian National Survey on Child Nutrition (ENANI-2019). The following items were included: the education level of the mother or caregiver of the child; the number of bedrooms and bathrooms, TV sets, and cars in the household; and the presence of a radio, refrigerator or freezer, washing machine, microwave oven, telephone line, computers, air conditioner, media player devices, cable or satellite TV, cell phone ownership and type of service, cell phone internet, and internet at the household. Principal component analysis (PCA) was used to estimate the IEN with and without incorporating the complex sampling design (CSD). Thus, the IEN validation considered proxy indicators of socioeconomic status and living conditions. The first component of the PCA explained 31% and 71% of the variation with and without incorporating the CSD, respectively. The coefficients of variation of the IEN were 53.4% and 2.6% with and without incorporating the CSD, respectively. The mean IEN score was lower in households without access to a sewage system, those that received benefits from Brazilian Income Transfer Program, those with some degree of food insecurity, and those with stunted children. Adding ENANI-2019 items to the calculation of IEN to capture technological advances resulted in a better fit of the model. Incorporating the CSD increased PCA performance and the IEN precision. The new IEN has an adequate performance in determining the socioeconomic status of households with children aged under five years.

Trends of breastfeeding indicators in Brazil from 1996 to 2019 and the gaps to achieve the WHO/UNICEF 2030 targets.

BACKGROUND: The comprehension of breastfeeding patterns and trends through comparable indicators is essential to plan and implement public health policies. OBJECTIVE: To evaluate the trends of breastfeeding indicators in Brazil from 1996 to 2019 and estimate the gap to achieve the WHO/UNICEF 2030 targets in children under 5 years. METHODS: Microdata from two National Surveys on Demography and Health of Women and Children (PNDS-1996 and PNDS-2006) and the Brazilian National Survey on Child Nutrition-2019 were used. The indicators of early initiation of breastfeeding (EIBF), exclusive breastfeeding of infants 0-5 months of age (EBF<6 mo), continued breastfeeding at 1 year of age (CBF1yr) and CBF at 2 years of age (CBF2yr) were analysed using prevalence and 95% CI. The average annual variation and years to achieve the WHO/UNICEF 2030 targets were calculated for Brazil and the macroregions. Statistical analyses considered the survey's complex sample design for each database. RESULTS: EIBF increased from 36.3% (95% CI 33.6% to 39.0%) in 1996 to 60.9% (95% CI 56.5% to 65.3%) in 2006 (statistically significant) and 62.5% (95% CI 58.3% to 66.6%) in 2019. EBF<6 mo increased from 26.9% (95% CI 21.3% to 31.9%) in 1996 to 39.0% (95% CI 31.0% to 47.1%) in 2006 and 45.8% (95% CI 40.9% to 50.7%) in 2019 (significant increases for 1996-2019 for Brazil, Northeast and Midwest regions). CBF1yr rose from 36.6% (95% CI 30.8% to 42.4%) in 1996 to 48.7% (95% CI 38.3% to 59.0%) in 2006, and 52.1% (95% CI 45.4% to 58.9%) in 2019. CBF2yr increased from 24.7% (95% CI 19.5% to 29.9%) in 1996 to 24.6% (95% CI 15.7% to 33.5%) in 2006 and 35.5% (95% CI 30.4% to 40.6%) in 2019 (significant increase for 1996-2019). The South and Southeast regions need to double the 2019 prevalence to reach the target for the CBF1yr and CBF2yr; the Northeast and North need to increase 60% the current prevalence for the indicator of EBF<6 mo. CONCLUSION: A substantial improvement in breastfeeding indicators occurred in Brazil from 1996 to 2019, although at an insufficient rate to achieve the WHO/UNICEF 2030 targets.

Minimum dietary diversity and consumption of ultra-processed foods among Brazilian children 6-23 months of age.

The study aimed to estimate the prevalence of minimum dietary diversity (MDD) and consumption of ultra-processed foods in children 6-23 months of age according to sociodemographic variables. Three indicators of complementary feeding of 4,354 children from the Brazilian National Survey on Child Nutrition (ENANI-2019) were built based on a questionnaire about food consumption on the day before the interview: MDD, consumption of ultra-processed foods, and MDD without the consumption of ultra-processed foods. The prevalence and 95%CI were calculated, stratified by macroregion; race/skin color, education and work status of the mother or caregiver; enrollment in the Brazilian Income Transfer Program; household food security; sanitation; and child enrollment in daycare/school. The overall prevalence of MDD was 63.4%, with lower prevalences among children who lived in the North Region (54.8%), whose mothers or caregivers had 0-7 years of education (50.6%), and lived under moderate or severe food insecurity (52.6%). Ultra-processed foods were consumed by 80.5% of the children, with the highest prevalence in the North Region (84.5%). The prevalence of MDD without ultra-processed foods was 8.4% and less prevalent among children with black mothers or caregivers (3.6%) and among those whose mother or caregiver had 8-10 years of education (3.6%). The most frequently consumed food groups from the MDD indicator were grains, roots and tubers (90.2%), dairy products (81%) and those from ultra-processed food were sweet or salty cookies/crackers (51.3%) and instant flours (41.4%). The ubiquitous presence of ultra-processed foods in the diets of Brazilian children and the low frequency of diversified foods, especially among the most vulnerable populations, indicate the need to strengthen policies and programs to ensure adequate and healthy infant nutrition.

Nutrition transition in Brazilian children under 5 years old from 2006 to 2019.

This manuscript aims to report the nutrition transition in Brazilian children under 5 years old from 2006 to 2019. Microdata from the Brazilian National Survey on Demography and Health of Women and Children (PNDS 2006) and the Brazilian National Survey on Child Nutrition (ENANI-2019) were analyzed. The indicators considered were: micronutrient status (anemia and vitamin A deficiency), anthropometric status (stunting and excessive weight), and breastfeeding practice (exclusive breastfeeding among children < 6 months and continued breastfeeding among children 12-23 months). We also analyzed minimum dietary diversity (MDD), consumption of ultra-processed foods, consumption of meat or eggs, and not consuming fruits or vegetables in children 6-59 months of age only for ENANI-2019. Equiplot charts were generated according to geographic region, maternal schooling level, and maternal race/skin color. From 2006 to 2019, the prevalence rates of anemia and vitamin A deficiency decreased from 20.5% to 10.1% and 17.2% to 6%, respectively. The prevalence of stunting remained at 7%, and excessive weight rates increased from 6% to 10.1%. The prevalence of exclusive breastfeeding among children < 6 months increased from 38.6% to 45.8%, and of continued breastfeeding among children 12-23 months from 34.6% to 43.6%. In 2019, 61.5% of children achieved the MDD, 88.8% consumed ultra-processed foods, 83.1% consumed meat or egg, and 25.7% did not consume fruits or vegetables the day before the survey. Trends of decreased micronutrient deficiencies, increased breastfeeding, and excessive weight rates, as well as reductions in disparities related to geographic region, maternal schooling level, and maternal race/skin color, were observed for most of the indicators.

Cross-breastfeeding and milk donation in Brazil.

The objective of this study was to describe the frequency of cross-breastfeeding, human milk donation to human milk banks and reception of human milk from human milk banks, and to investigate the intersection between cross-breastfeeding and breast milk donation practices. This study used data from the national household-based survey Brazilian National Survey on Child Nutrition (ENANI-2019), which collected information from 14,558 children < 5 years old between February 2019 and March 2020. The present study included data from 5,831 biological mothers who reported having breastfed their child < 2 years old at least once and replied questions about cross-breastfeeding, donation and recaption of human milk to human milk banks. Prevalence and 95% confidence intervals (95%CI) were estimated for each stratifier, considering the study complex sample design. Among mothers of children < 2 years old who breastfed their child at least once, 21.1% practiced cross-breastfeeding; breastfeeding another child was more frequent (15.6%) than allowing a child to be breastfed by another woman (11.2%). Among this population, 4.8% of women donated human milk to a human milk bank, and 3.6% reported that their children had received donated human milk. The donation of human milk is a practice recommended by the Brazilian Ministry of Health and has the potential to save thousands of newborns throughout Brazil. In contrast, cross-breastfeeding is contraindicated due to the potential risk of transmitting HIV. There is a need for a broad debate on these practices in Brazil and worldwide.

Malnutrition in mother-child dyads in the Brazilian National Survey on Child Nutrition (ENANI-2019).

Malnutrition affects billions of individuals worldwide and represents a global health challenge. This study aimed to determine the prevalence of malnutrition (undernutrition or overweight) among mother-child dyads in children under 5 years old in Brazil in 2019 and to estimate changes in this prevalence from 2006 to 2019. Individual-level data from the Brazilian National Survey on Child Nutrition (ENANI-2019) and the Brazilian National Survey of Demography and Health of Women and Children carried out in 2006 (PNDS 2006) were analyzed. Malnutrition outcomes in mother-child dyads included overweight mother and child, undernourished mother and child, and the double burden of malnutrition, i.e., overweight mother and child having any form of undernourishment (stunting, wasting, or underweight). Prevalence and 95% confidence intervals (95%CI) were estimated. Most women (58.2%) and 9.7% of the children were overweight, 6.9% were stunted, and 3.1% of mothers and 2.9% of the children were underweight. The prevalence of overweight in the mother-child dyad was 7.8% and was statistically higher in Southern Brazil (9.7%; 95%CI: 7.5; 11.9) than in the Central-West (5.4%; 95%CI: 4.3; 6.6). The prevalence of overweight mother and stunted child was 3.5%, with statistically significant difference between the extremes of the mother's education [0-7 vs. ≥ 12 years, 4.8% (95%CI: 3.2; 6.5) and 2.1%, (95%CI: 1.2; 3.0), respectively]. Overweight in the dyad increased from 5.2% to 7.8%, and the double burden of malnutrition increased from 2.7% to 5.2% since 2006. Malnutrition in Brazilian mother-child dyads seems to be a growing problem, and dyads with lower formal education, higher maternal age, and from the South Region of Brazil were more vulnerable.

Factors associated with anemia and vitamin A deficiency in Brazilian children under 5 years old: Brazilian National Survey on Child Nutrition (ENANI-2019).

Factors associated with anemia and vitamin A deficiency were investigated in 7,716 children 6-59 months of age studied in the Brazilian National Survey on Child Nutrition (ENANI-2019). We adopted a hierarchical approach based on a United Nations Children's Fund (UNICEF) theoretical model with three levels, stratifying by age (6-23; 24-59 months). Prevalence ratio (PR) and 95% confidence interval (95%CI) were estimated. Enabling determinants: a higher prevalence of anemia was observed in children 6-23 months whose mothers had ≤ 7 years of schooling (PR = 1.92; 95%CI: 1.10; 3.34), < 20 years old (PR = 2.47; 95%CI: 1.34; 4.56) or 20-30 years old (PR = 1.95; 95%CI: 1.11; 3.44), mixed-race (PR = 1.57; 95%CI: 1.06; 2.23); and in children 24-59 months in the North Region (PR = 3.11; 95%CI: 1.58; 6.13). A higher prevalence for vitamin A deficiency was observed in children 6-23 months from Central-West (PR = 2.32; 95%CI: 1.33; 4.05), and in children 24-59 months living in the North (PR = 1.96; 95%CI: 1.16; 3.30), South (PR = 3.07; 95%CI: 1.89; 5.01), and Central-West (PR = 1.91; 95%CI: 1.12; 3.25) and whose mothers were 20-34 years (PR = 1.62; 95%CI: 1.11; 2.35). Underlying determinants: the presence of more than one child < 5 years old in the household was associated with a higher prevalence of anemia (PR = 1.61; 95%CI: 1.15; 2.25) and vitamin A deficiency (PR = 1.82; 95%CI: 1.09; 3.05) in children 6-23 months. Immediate determinants: consumption of 1-2 groups of ultra-processed foods in children 24-59 months (PR = 0.44; 95%CI: 0.25; 0.81) and lack of breastfeeding in the day before in children 6-23 months (PR = 0.56; 95%CI: 0.36; 0.95) were associated with lower prevalence of anemia and vitamin A deficiency. Public policies focused on geographically and socially vulnerable groups are needed to promote equity.

Sampling plan of the Brazilian National Survey on Child Nutrition (ENANI-2019): a population-based household survey.

The article describes methodological aspects in defining the study population, sampling plan, and sample weigthing and calibration of effective sample of the Brazilian National Survey on Child Nutrition (ENANI-2019). This population-based household survey assessed breastfeeding and dietary intake, anthropometric assessment of nutritional status, and micronutrient deficiencies by blood biomarkers in children under five years of age. The data were obtained with a probability sample, with stratification by the five geographic regions in the country and clustering by census enumeration areas (CEAs). The sample was calculated at 15,000 households distributed in 1,500 CEAs, with 300 allocated in each of Brazil's five major geographic regions and 10 eligible households per CEA, sampled using inverse sampling. The required population parameters were thus estimated to reach the study's objectives. The basic sampling design weights were calculated as the inverse probabilities of the households' inclusion in the study. Imputation was used to compensate for non-response to items in the target variables, except for data on the blood biomarkers. Finally, calibration used population totals of children in 60 post-strata, defined by cross-classification of the following variables: major geographic region, sex, and age. The final sample included 14,558 children residing in 12,524 households, distributed in 1,382 CEAs in the 26 states of Brazil and the Federal District. The data from the ENANI-2019 survey will support strategies for the promotion and implementation of public policies for children under five years of age.

Methodological aspects of the anthropometric assessment in the Brazilian National Survey on Child Nutrition (ENANI-2019): a population-based household survey.

The article presents methodological aspects of anthropometric assessment of nutritional status in children under five years of age and their biological mothers. It discusses the strategies used for training and data collection in the Brazilian National Survey on Child Nutrition (ENANI-2019). ENANI-2019 is a population-based household survey conducted in 123 municipalities in Brazil's 26 states and the Federal District. The anthropometric measurements were body mass and length/stature. The equipment was purchased according to its measurement capacity and precision, portability, and cost-benefit ratio after an extensive market search. The study used internationally established procedures described in manuals, videos, and support material developed for the study by a group of experts. The interviewers were trained to perform the anthropometric measurements and were assessed according to technical measurement error, which was considered adequate (0.30cm) for the children's length/stature measurements. Measurement errors were identified, and the interviewers were retrained when necessary. Of the 14,558 children in the sample, body mass and length/stature measurements were taken in duplicate in 13,835 and 13,693 children, respectively. The standardized methodological aspects will be helpful in future population studies and were essential for obtaining greater reliability in the data for generating current evidence on the anthropometric assessment of the nutritional status of Brazilian children under five years of age, allowing new perspectives for public policy development.

General methodological aspects in the Brazilian National Survey on Child Nutrition (ENANI-2019): a population-based household survey.

This article aims to present general methodological aspects of the Brazilian National Survey on Child Nutrition (ENANI-2019), from the conception of the study design to details of the data collection. This is a household-based population survey with a sample calculated at 15,000 households to identify children under five years of age, conducted in 123 municipalities in Brazil's 26 states and the Federal District. ENANI-2019 includes data on breastfeeding and dietary intake; anthropometric nutritional status of all children and their biological mothers; and nutritional status concerning the following micronutrients: iron (hemoglobin and ferritin), zinc, selenium, and vitamins A, B1, B6, B12, D, E, and folic acid of children from 6 to 59 months of age. A total of 193,212 households were visited, of which 19,951 were eligible, and 12,524 were included in the study. A total of 14,558 children were studied, of whom 13,990 (96.1%) and 13,921 (95.6%) had their body mass and length/stature measured, respectively, and 14,541 (99.9%) underwent 24-hour dietary recalls (24HR). Of the 12,598 children eligible for blood sample collection, 8,739 (69.3%) had at least one laboratory parameter measured. Data were collected from February 2019 to March 2020, when the survey was interrupted due to the COVID-19 pandemic. The evidence produced by the ENANI-2019 survey can back the formulation, follow-up, and/or reorientation of food and nutrition policies such as the promotion of breastfeeding and healthy eating and the prevention and control of different forms of malnutrition.

Methodological aspects of the micronutrient assessment in the Brazilian National Survey on Child Nutrition (ENANI-2019): a population-based household survey.

This article aims to present methodological aspects on the collection, analyses, coverage, challenges, and the lessons learned from laboratory assessment of micronutrients on the Brazilian National Survey on Child Nutrition (ENANI-2019). This is a household survey on a probability sample of children under five years of age from 123 Brazilian municipalities in all 26 states and the Federal District. Blood samples were drawn by venipuncture at the homes of children 6 to 59 months of age. This procedure was performed by experienced phlebotomists from the laboratories located in the selected municipalities and scheduled in advance. Blood and serum levels were measured for biomarkers of nutritional status, using the services of a clinical test laboratory with nationwide coverage, for the following micronutrients: iron (hemoglobin and ferritin), zinc, selenium, folic acid, and vitamins A, B1, B6, B12, D, and E. C-reactive protein was analyzed as a marker of inflammation. A barcode identifier was used to track the blood samples and to link the biochemical test results to the other data collected in the survey. A total of 14,558 children were studied. Of the 12,598 eligible children, 8,829 (70.1%) had blood samples drawn. Of the total number of children who had samples drawn, 91.8% (n = 8,025) have results for at least nine of the 12 analyses performed. Coverage of the analysis varied from 95% (for vitamins A and E) to 84.2% (for folic acid). Aliquots of whole blood and serum were stored in a biorepository for future analyses. The results of this pioneering study in the country will back the formulation and, when necessary, the reorientation of public policies in food and nutrition.

Methodological aspects of the assessment of dietary intake in the Brazilian National Survey on Child Nutrition (ENANI-2019): a population-based household survey.

This manuscript aims to describe the methodological, operational, and quality control aspects of the assessment of dietary intake in children under five years of age participating in the Brazilian National Survey on Child Nutrition (ENANI-2019), a household survey in a probability sample of Brazilian households. Two instruments were developed to assess child feeding practices - a structured, current status-type questionnaire and a 24-hour dietary recall (24HR), both installed in a mobile data collection device used by previously trained interviewers. A Photographic Manual for Quantification of Children's Dietary Intake was specifically developed for and used in the survey as a support aid to identify and quantify foods reported in the 24HR. During the fieldwork, continuous quality control of the records was performed. Data errors or incomplete data in the system were corrected, and the fieldwork team was systematically contacted and informed on their performance, with reiterated orientation on data collection. All children in the sample were evaluated with the two instruments, but data were obtained from the structured questionnaire on all children in the sample (n = 14,558) and 24HR on 14,541 children. ENANI-2019 developed innovative methods and materials based on the Brazilian and international literature to address knowledge gaps on under-five children's dietary intake. Unprecedented results will be produced, which will allow updating food and nutrition guidelines for children under five years of age in Brazil.