Dietary iron intake over two post-fortification periods in Brazil: data from the National Dietary Surveys 2008-2009 and 2017-2018.

We aimed to assess the dietary Fe intake and the prevalence of inadequate Fe intake over two post-fortification periods in Brazil. The intake was analysed according to sex, life stage, geographic region and stratum of family income per capita. Excluding pregnant and lactating women, this population-based study included 32 749 and 44 744 participants aged ≥ 10 years from the National Dietary Survey-Brazilian Household Budget Surveys 2008-2009 and 2017-2018, respectively. The National Cancer Institute method was used to predict usual dietary Fe intakes. The prevalence of Fe intake inadequacy was estimated following a probabilistic approach for women of childbearing age or with the Estimated Average Requirement cut-off point method. Over an interval of 10 years, the mean Fe intake remained almost unchanged for most sex-age groups, except for women of childbearing age. In this specific group, the prevalence of Fe intake inadequacy was > 20 % in 2008-2009 and have increased to > 25 % in 2017-2018, with the highest reductions in mean Fe intake found in the highest income strata and richest Brazilian regions. Meanwhile, the highest prevalence of Fe intake inadequacy (> 40 %) occurred among the poorest women aged 31-50 years from the lowest family income stratum, irrespective of the study period. Beans were the main Fe source, while fortified breads, pastas, pizzas, cakes and cookies contributed approximately 40 % of the Fe intake. The results provide important insights into the long-standing dietary impacts of food fortification, which can guide future (re)formulation of effective public health strategies to combat Fe deficiency.

Prevalence of inadequate intake of folate after mandatory fortification: results from the first National Dietary Survey in Brazil.

PURPOSE: Our aim was to estimate the prevalence of folate inadequacy (POFI) according to life stage, socio-economic status, and geographical regions after the mandatory fortification of wheat and maize flour in Brazil. METHODS: This was a population-based study. Data from two non-consecutive food records from the National Dietary Survey/Household Budget Survey 2008-2009 were used to estimate the usual dietary folate intake in µg dietary folate equivalents (DFEs). The National Cancer Institute method was used to account for within-person variance and the Estimated Average Requirement (EAR) cut-point method was used to calculate the POFI. The survey included 32,749 individuals, 15,700 males and 17,049 females, over 10 years old. Pregnant women, lactating women, and individuals with unreliable energy intake data were excluded. RESULTS: Overall POFI was 31.5% and mean dietary folate intake was 411.1 µg DFE. The lowest POFI occurred in the youngest age group of 10-13 years in both sexes, while the highest POFI was observed in the group ≥ 71 years. In women of childbearing age, POFI was around 32%. The lowest income strata had the highest POFI. The most developed regions (South and Southeast) had the lowest POFI compared to less developed regions. CONCLUSIONS: Our data show that folate inadequacy is still prevalent in Brazil mainly in low-income groups and less developed regions. Actions need to be taken to ensure that women of childbearing age, who presented a high prevalence of inadequate folate intake, achieve the recommended daily intake of 400 µg DFEs.

Brazilians' experiences with iron fortification: evidence of effectiveness for reducing inadequate iron intakes with fortified flour policy.

OBJECTIVE: To assess Fe intake, calculate the prevalence of inadequate Fe intake and identify food contributors to Fe intake during 2003 and 2008 in a population-based study, reflecting before and after the mandatory fortification of flour with Fe. DESIGN: Two cross-sectional population-based studies conducted in 2003 and 2008. Dietary intake was evaluated by 24 h recall and the Software for Intake Distribution Estimation (PC-SIDE) was used to estimate within-person variance and prevalence of inadequate Fe intake. The statistical analysis was conducted considering the complex survey design. SETTING: São Paulo, Brazil. SUBJECTS: Adolescents, adults and elderly adults of both sexes, interviewed in 2003 (n 2386) and 2008 (n 1661). RESULTS: The Fe intake mean increased in all populations in the post-fortification period. A reduction of over 90 % was observed in the prevalence of inadequate Fe intake among men for all age groups analysed. When evaluating women, despite the substantial reduction (over 63 %), prevalence of inadequate Fe intake remained high (34 %) in those aged 19-50 years. Major food contributors to Fe intake before fortification were beans, beef, vegetables and dairy. There was an alteration in the contributors in the post-fortification period, with bread, beef, beans and biscuits as main contributors. CONCLUSIONS: The mandatory fortification with Fe significantly furthered the reduction in the prevalence of inadequacy, except among women of reproductive age, and changed the main contributors to this nutrient in the studied population. Therefore, monitoring of Fe addition in flour is essential to assess compliance to the fortified flour policy and to guarantee a safe Fe intake for all the population.

Performance of statistical methods to correct food intake distribution: comparison between observed and estimated usual intake.

There are statistical methods that remove the within-person random error and estimate the usual intake when there is a second 24-h recall (24HR) for at least a subsample of the study population. We aimed to compare the distribution of usual food intake estimated by statistical models with the distribution of observed usual intake. A total of 302 individuals from Rio de Janeiro (Brazil) answered twenty, non-consecutive 24HR; the average length of follow-up was 3 months. The usual food intake was considered as the average of the 20 collection days of food intake. Using data sets with a pair of 2 collection days, usual percentiles of intake of the selected foods using two methods were estimated (National Cancer Institute (NCI) method and Multiple Source Method (MSM)). These estimates were compared with the percentiles of the observed usual intake. Selected foods comprised a range of parameter distributions: skewness, percentage of zero intakes and within- and between-person intakes. Both methods performed well but failed in some situations. In most cases, NCI and MSM produced similar percentiles between each other and values very close to the true intake, and they better represented the usual intake compared with 2-d mean. The smallest precision was observed in the upper tail of the distribution. In spite of the underestimation and overestimation of percentiles of intake, from a public health standpoint, these biases appear not to be of major concern.

Inadequate nutrient intake among the Brazilian elderly: National Dietary Survey 2008-2009.

OBJECTIVE: To estimate the prevalence of inadequate nutrient intake in the Brazilian elderly. METHODS: This study was based on data from the National Dietary Survey, part of the Household Budget Survey 2008-2009. All individuals aged 60 and over, totaling 4,322 individuals, were included. Individual food intake was obtained from food records from two non-consecutive days. The habitual intake for each nutrient was estimated by the National Cancer Institute method, in which sex and region were included as covariates. The prevalence of inadequate nutrient intake was estimated stratified by sex and region using the EAR method to define cut-off points. RESULTS: A high prevalence of inadequate intake (> 50%) of vitamins E, D and A, calcium, magnesium and pyridoxine was observed for both sexes. In all regions, 100% inadequate vitamin E intake was observed. Vitamin D showed almost 100% inadequate intake except in the North region. The prevalence of inadequate vitamin A intake was higher than 70% in the North, Northeast, and Midwest regions. Among the minerals evaluated, calcium and magnesium showed the highest prevalence of inadequate intake (> 80%) in all regions. CONCLUSIONS: The present study found a high prevalence of inadequate intake of nutrients recognized as being protective against chronic diseases among the Brazilian elderly.

Prevalence and correlates of calcium and vitamin D status adequacy in adolescents, adults, and elderly from the Health Survey-São Paulo.

OBJECTIVE: In addition to the importance of adequate calcium and vitamin D status for health and prevention of several chronic diseases, a high prevalence of both nutrient inadequacy and 25-hydroxyvitamin D (25[OH]D) insufficiency has been observed. The aim of this study was to estimate calcium and vitamin D status correlates and adequacy from a population-based epidemiologic study. METHODS: This is a subsample of a cross-sectional study of a representative sample of individuals living in São Paulo that includes 636 participants. A 24-h dietary record and a blood sample were collected. Nutrient adequacy was estimated by adjusting for the within-person variance of the nutrient intake. Serum concentration of 25(OH)D was measured by high-performance liquid chromatography and considered adequate when ≥ 50 nmol/L. RESULTS: Calcium and vitamin D intake decrease according to life stages in both men and women, and increases with family income and educational level. The prevalence of calcium intake inadequacy is higher than 70% and almost 100% for vitamin D. The highest 25(OH)D concentration was observed in the fall-51.7 (20.4) nmol/L-and lowest in the summer-30.1 (8.8) nmol/L. Sex, body mass index, physical activity, alcohol and smoking habits, life stage, family income, skin color, waist circumference, and season of the year could explain 22% of the variability of 25(OH)D. CONCLUSIONS: The present study demonstrates important inadequacies regarding the nutritional status of calcium and vitamin D and indicates an urgent need not only for health professionals, but also for government and food industries to undertake new initiatives that could result in a real improvement in terms of calcium and vitamin D nutrition.

[Evaluation of the safety of different doses of folic acid supplements in women in Brazil]. / Avaliação da segurança de diferentes doses de suplementos de ácido fólico em mulheres do Brasil.

OBJECTIVE: To evaluate the distribution of folic acid intake and the safety of different doses of supplements in women of childbearing age. METHODS: Data were used from two non-consecutive days of food records of 6,837 women of childbearing age (19-40 years old) participants of the National Food Survey, a module of the Household Budget Survey 2008-2009. Means and percentiles of usual consumption of natural folate and folic acid were estimated using the National Cancer Institute method. Five scenarios were simulated by adding different daily doses of fortification (400 mcg, 500 mcg, 600 mcg, 700 mcg and 800 mcg) to folic acid derived from food consumed by the women. To define a safe dose of the supplement, the total folate (dietary + supplement) was compared with the tolerable upper intake level (UL = 1,000 mcg). RESULTS: Women with usual intake of folic acid above the tolerable upper intake levels were observed only for doses of supplement of 800 mcg (7.0% of women). Below this value, any dose of the supplement was safe. CONCLUSIONS: The use of supplements of up to 700 mcg of folic acid was shown to be safe.

Precision of usual food intake estimates according to the percentage of individuals with a second dietary measurement.

BACKGROUND: Statistical methods for estimating usual intake require at least two short-term dietary measurements in a subsample of the target population. However, the percentage of individuals with a second dietary measurement (replication rate) may influence the precision of estimates, such as percentiles and proportions of individuals below cut-offs of intake. OBJECTIVE: To investigate the precision of the usual food intake estimates using different replication rates and different sample sizes. PARTICIPANTS/SETTING: Adolescents participating in the continuous National Health and Nutrition Examination Survey 2007-2008 (n=1,304) who completed two 24-hour recalls. STATISTICAL ANALYSES PERFORMED: The National Cancer Institute method was used to estimate the usual intake of dark green vegetables in the original sample comprising 1,304 adolescents with a replication rate of 100%. A bootstrap with 100 replications was performed to estimate CIs for percentiles and proportions of individuals below cut-offs of intake. Using the same bootstrap replications, four sets of data sets were sampled with different replication rates (80%, 60%, 40%, and 20%). For each data set created, the National Cancer Institute method was performed and percentiles, CI, and proportions of individuals below cut-offs were calculated. Precision estimates were checked by comparing each CI obtained from data sets with different replication rates with the CI obtained from original data set. Further, we sampled 1,000, 750, 500, and 250 individuals from the original data set, and performed the same analytical procedures. RESULTS: Percentiles of intake and percentage of individuals below the cut-off points were similar throughout the replication rates and sample sizes, but the CI increased as the replication rate decreased. Wider CIs were observed at 40% and 20% of replication rate. CONCLUSIONS: The precision of the usual intake estimates decreased when low replication rates were used. However, even with different sample sizes, replication rates >40% may not lead to an important loss of precision.