Marginal vitamin and mineral intake of Costa Rican adolescents

Global Trends in the Availability of Dietary Data in Low and Middle-Income Countries

Individual-level quantitative dietary data can provide suitably disaggregated information to identify the needs of all population sub-groups, which can in turn inform agricultural, nutrition, food safety, and environmental policies and programs. The purpose of this discussion paper is to provide an overview of dietary surveys conducted in low- and middle-income countries (LMICs) from 1980 to 2019, analyzing their key characteristics to understand the trends in dietary data collection across time. The present study analyzes the information gathered by the Food and Agriculture Organization of the United Nations/World Health Organization Global Individual Food consumption data Tool (FAO/WHO GIFT). FAO/WHO GIFT is a growing repository of individual-level dietary data and contains information about dietary surveys from around the world, collected through published survey results, literature reviews, and direct contact with data owners. The analysis indicates an important increase in the number of dietary surveys conducted in LMICs in the past four decades and a notable increase in the number of national dietary surveys. It is hoped that this trend continues, together with associated efforts to validate and standardize the dietary methods used. The regular implementation of dietary surveys in LMICs is key to support evidence-based policies for improved nutrition.

Inadequacy of vitamins and minerals among high-school pupils in Ouarzazate, Morocco

OBJECTIVE

To assess micronutrient intakes and the prevalence of inadequacy in a sample of high-school pupils in Ouarzazate, Morocco.

DESIGN

Food records were compiled over three non-consecutive days by pre-trained pupils. Micronutrient intakes were estimated using the DIAL software, adapted to include foods commonly eaten in Morocco. The prevalence of inadequacy was estimated by the proportion of individuals with intakes below the Estimated Average Requirement (EAR) for vitamins B12, A and K, thiamin, riboflavin, niacin, pyridoxine, folate, ascorbic acid, iodine, Ca, Mg and P; below the Adequate Intake (AI) level for pantothenic acid, biotin, Na and K; and using the probability approach for Fe. Data were adjusted for intra-individual variation with exclusion of under-reporters.

SETTING

Ouarzazate, a semi-urban region situated on the southern slopes of the High Atlas with little industrial development but an important tourism sector.

SUBJECTS

A self-selected sample of 312 pupils aged 15-19 years from the five public high schools. After exclusion of under-reporters, 293 remained for analysis.

RESULTS

The highest proportions of below-EAR/AI intakes were seen for pantothenic acid (girls 85·1 %, boys 78·0 %), biotin (boys 83·1 %, girls 79·4 %), thiamin (boys 66·9 %), folate (girls 93·1 %, boys 74·6 %), iodine (boys 94·9 %, girls 88·0 %) and Ca (girls 83·4 %, boys 74·6 %). Na intake was generally in excess whereas K intake was below the AI level. In general, girls had better-quality diets than boys, who appeared to consume more 'empty calories'.

CONCLUSIONS

Our findings suggest that in this population of Moroccan adolescents, nutritional intervention and educational strategies are needed to promote healthy eating habits and correct micronutrient inadequacies. To provide reliable and precise estimates of nutrient intakes, an update of Moroccan food composition databases is urgently needed. We recommend that national authorities address these issues.

Application of the high-performance liquid chromatography method with coulometric detection for determination of vitamin B(6) in human plasma and serum

A reversed-phase high-performance liquid chromatography method (HPLC) with coulometric electrochemical detection has been developed and validated for the simultaneous analysis of pyridoxamine-5'-phosphate (PMP), pyridoxamine (PM), pyridoxal 5'-phosphate (PLP), pyridoxal (PL), pyridoxine (PN) and 4-pyridoxic acid (4-PA) in human plasma and serum. The isocratic separation was achieved on C(18) column (250mmx4.6mm, I.D., 5microm) with a mobile phase consisted of 35mM sodium phosphate containing 2.5mM heptanesulfonic acid, adjusted to pH 3.2 with 85% orthophosphoric acid and 12% methanol (v/v). Within-run and between-run precisions expressed by the relative standard deviations were less than 2.7% and 7.7% for all the analysed vitamins and 4-PA, respectively. The limits of detection (LOD) and quantification (LOQ) were: 0.8 and 2.6nM, 1.1 and 3.8nM, 1.5 and 4.5nM, 1.3 and 4.2nM, 1.1 and 3.7nM, 2.1 and 6.3nM for PMP, PM, PLP, PL, PN and 4-PA, respectively. The recoveries ranged from 90.4% to 98.4%. Stability of vitamins was checked under a variety of storage conditions. The developed application demonstrated acceptable sensitivity, precision, accuracy, stability, and linearity over the physiological concentration range. The major advantage of the proposed method is its great simplicity.

Vitamin B6 status assessment in relation to dietary intake in high school students aged 16-18 years

The vitamin B6 status of high school students and its relationship with dietary intake were investigated in this cross-sectional study by face-to-face interview. A total of 157 healthy students aged 16-18 years (eighty-three boys and seventy-four girls) were randomly recruited from two out of nineteen senior high schools in Tainan, Taiwan. Vitamin B6 intakes were calculated from three 24-h dietary records. Direct and indirect vitamin B6 status indicators were measured in plasma, erythrocytes and urine. The anthropometric data, being similar to those of the first Nutrition and Health Survey in Taiwan (1993-1996), showed the normal growth and development of these students. All students except one girl (28.7 nmol/l) had plasma pyridoxal-5'-phosphate (PLP) levels >35 nmol/l, indicating an adequate vitamin B6 status. The mean dietary vitamin B6 intakes of boys and girls were 1.04 (sd 0.29) and 0.96 (sd 0.27) mg/d, respectively. Vitamin B6 status indicators, including plasma PLP, erythrocyte alanine aminotransferase activity coefficient (EALT-AC), aspartate aminotransferase activity coefficient (EAST-AC) and urinary 4-pyridoxic acid (4-PA), were correlated with vitamin B6 intake. Students with adequate values of plasma PLP (>35 nmol/l), EALT-AC ( < 1.25), EAST-AC ( < 1.8) and urinary 4-PA (>3.0 micromol/d) had median intakes of 1.08 and 1.01 mg/d, respectively, for boys and girls. This study suggests that vitamin B6 requirements for boys and girls aged 16-18 years were approximately 1.1 and 1.0 mg/d, respectively.

A Monte Carlo simulation to validate the EAR cut-point method for assessing the prevalence of nutrient inadequacy at the population level

Objective:

The aim of this study was to validate the EAR cut-point method for assessing the prevalence of nutrient inadequacy at the population level.

Design and subjects:

Different methods for estimating the prevalence of inadequate intake were compared: the cut-off point method, with cut-off points at the Recommended Dietary Allowance (RDA), 0.66 RDA, 0.50 RDA and the Estimated Average Requirement (EAR); the probability approach; and a Monte Carlo simulation. In total, 591 men and 674 women, aged 20–55 years, were included in the analyses.

Results:

The prevalence of inadequate intake as estimated by the EAR cut-point method was similar to the prevalence of inadequacy estimated by both probabilistic methods. The cut-point method with RDA, 0.66 RDA and 0.50 RDA as cut-off limits induced an over- or an underestimation of the real prevalence of inadequacy.

Conclusions:

Probabilistic methods consider both the intake variability and the requirement variability, and, as a result, their estimation should be closer to the real prevalence of inadequacy. The use of the EAR cut-point method yields a good estimation of the prevalence of inadequate intake, comparable to the probability approach, and limits over- and underestimation of the prevalence induced by other cut-off points.

Development and validation of a questionnaire to test knowledge and practices of dietitians regarding dietary supplements

OBJECTIVE

We developed a questionnaire to evaluate dietitians' knowledge and practices about the use of dietary supplements in light of new draft regulations in South Africa that will allow dietitians to prescribe supplements for the management of nutrition-related diseases.

METHODS

A cross-sectional validation study was carried out in two phases: 1) questionnaire planning and development and 2) determination of reliability (internal consistency). The study sample comprised 48 nurses, 105 dietetic interns, and 367 registered dietitians. An expert academic group comprising nine dietitians with research and teaching experience rated the academic relevance and importance of knowledge questions in an item pool of 355 questions to ensure face and content validity. Criterion validity was measured by testing the knowledge questions (KQs) on 48 nurses and 105 dietetic interns. Thereafter questions were deleted based on their difficulty, discrimination, and Cronbach's alpha values. The final questionnaire, which at this point included a test of 50 KQs, was mailed to registered dietitians (n = 1450) in South Africa to determine internal consistency of the final KQs.

RESULTS

Criterion validity of the KQs was indicated by a significant difference (P = 0.000) in the mean test scores between nurses (36.9, 95% confidence interval 24.2 to 39.6) and dietetic interns (40.2, 95% confidence interval 38.8 to 41.7). Item discrimination was attained by the deletion of NQs having a minimum correlation of 0.20 with overall test score. Further, item difficulty was controlled for by removal of questions correctly answered by more than 80% (too easy) or fewer than 20% (too difficult). Internal consistency of the KQs, after completion by 367 dietitians, was 0.87 (Cronbach's alpha). The mean knowledge score of dietitians ranged from 56.5% to 62.5%, with the oldest group (> or =40 y) having the highest score (P = 0.018). Thirty-eight percent of dietitians recommended dietary supplements at least 3 times a week; 51% consumed dietary supplements themselves; and 17% sold them to clients.

CONCLUSIONS

A valid and reliable questionnaire that tests knowledge and practices of dietary supplements was developed for dietitians. This tool can be used by academic institutions to evaluate the knowledge and practices of final-year students. It can also be used on a representative sample of dietitians in South Africa and possibly elsewhere within the profession.

Barriers to and motivators for healthful eating as perceived by rural and urban Costa Rican adolescents

OBJECTIVE

To assess the perceptions of rural and urban Costa Rican adolescents about their diet and the factors they consider significant to healthful eating.

DESIGN

Data were collected in focus group discussions.

PARTICIPANTS

The study sample included 108 male and female adolescents aged 12 to 18 years. Adolescents were recruited among 7th to 11th grade students interested in taking part in the study.

SETTING

Two urban and one rural high school in San José, Costa Rica.

PHENOMENA OF INTEREST

Diet perceptions and barriers to and motivators for healthful eating.

ANALYSIS

Data were reviewed for emerging themes, and themes were coded applying content analysis procedures. The conceptual model for understanding adolescent eating behavior, proposed by Story and colleagues, served as the framework for this study.

RESULTS

Factors perceived as barriers to adopting healthful eating practices included unavailability of healthful food in the school environment, inadequate food choices within the family diet, and the peer-group notion among males and females that healthful eating by males is effeminate. Factors perceived as motivators included improving the nutritional quality of foods available at school, adoption of healthful eating practices by the entire family, and healthful eating becoming a peer-group social norm.

CONCLUSIONS AND IMPLICATIONS

This study suggests that the family, peer group, and school environment are potential targets for nutrition interventions for Costa Rican adolescents, but further studies are needed to confirm this conclusion. Future studies should explore in depth the factors associated with the family's eating pattern and the influence of adolescent socialization patterns (particularly male) in the establishment of a healthful diet.

Assessment of Vitamin B-6 Estimated Average Requirement and Recommended Dietary Allowance for Adolescents Aged 13–15 Years Using Vitamin B-6 Intake, Nutritional Status and Anthropometry

Because of limited available information, the Estimated Average Requirement (EAR) and Recommended Dietary Allowance (RDA) of vitamin B-6 for adolescents were recently estimated by extrapolation from adult values. To determine vitamin B-6 requirements and to provide recommendations for intakes, vitamin B-6 intake, nutritional status and anthropometry were studied in 134 healthy adolescents (63 boys and 71 girls) aged 13-15 y in Tainan, Taiwan. Direct and indirect vitamin B-6 indicators were measured in plasma, erythrocytes and urine. The anthropometric data of the adolescents in this study were similar to those of the first Nutrition and Health Survey in Taiwan (NAHSIT), conducted from 1993 to 1996, showing the normal growth and development of this adolescent group. All subjects had plasma pyridoxal-5'-phosphate (PLP) concentrations > or = 20 nmol/L, indicating an adequate vitamin B-6 status. The mean dietary vitamin B-6 intakes of boys and girls were 1.04 +/- 0.24 and 0.83 +/- 0.26 mg/d, respectively. Vitamin B-6 status indicators, including plasma PLP, erythrocyte alanine activity coefficient (EALT-AC), aspartate aminotransferase activity coefficient (EAST-AC) and urinary 4-pyridoxic acid (4-PA), were correlated with vitamin B-6 intake (r = 0.84, -0.84, -0.77 and 0.86, respectively, P < 0.01). Adequate values of plasma PLP (> or = 20 nmol/L), EALT-AC (<1.25), EAST-AC (<1.8) and urinary 4-PA (>3.0 micromol/d) were used to determine the EAR according to the Dietary Reference Intake committee methodology. The present study suggests that vitamin B-6 EAR (RDA) for adolescent boys and girls aged 13-15 y are 1.07 (1.28) and 0.90 (1.08) mg/d, respectively.

Diarrhea caused by enterotoxigenic Escherichia coli infection of humans is inhibited by dietary calcium

BACKGROUND & AIMS

In several rat infection experiments, we have shown that dietary calcium inhibits intestinal colonization and translocation of invasive salmonella. The aim of the present study was to find out whether calcium is also protective against enterotoxigenic Escherichia coli (ETEC) infection. This was first tested in our rat model and subsequently verified in a human infection study.

METHODS

Rats were fed a purified diet with either a low or a high amount of calcium phosphate and orally infected with ETEC. In addition, a parallel, double-blind, placebo-controlled intervention study of 3 weeks was performed with 32 healthy men. Subjects largely maintained their habitual diet and consumed either regular milk products (calcium supply, 1100 mg/day) or placebo milk products (calcium supply, 60 mg/day). On day 10, subjects ingested a live but attenuated ETEC strain (strain E1392/75-2A), able to induce mild although short-lived symptoms. Primary outcomes studied were infection-induced diarrhea (total fecal output and relative fecal dry weight) and fecal mucin excretion.

RESULTS

In humans, ETEC induced diarrhea in both groups, in that total fecal output doubled and mean relative fecal dry weight dropped from 25% to 20%. Additionally, fecal mucin excretion was increased in both groups. All these fecal parameters were completely normalized in the calcium group on the second infection day, in contrast to the placebo group, which recovered on the third infection day. Likewise, supplemental calcium inhibited ETEC colonization and diarrhea in rats.

CONCLUSIONS

Calcium in milk products improves human resistance to ETEC infection as it inhibits infectious diarrhea.

B vitamins and plasma homocysteine concentrations in an urban and rural area of Costa Rica

OBJECTIVE

We studied the association between total plasma homocysteine (tHcy) concentrations and folate, B(12), and B(6) status in the urban and rural areas of Costa Rica.

SUBJECTS AND METHODS

We determined plasma tHcy concentrations and assessed dietary folate, B(12) and B(6) intake by a food frequency questionnaire in 462 subjects selected by stratified random sampling in the urban and rural areas of Puriscal, Costa Rica. Plasma folate and vitamin B(12) concentrations were measured in women.

RESULTS

THcy concentrations were higher (p < 0.01) in the rural compared with the urban area: 12.0 micro mol/L vs. 8.9 micro mol/L in men, and women 7.3 micro mol/L vs. 5.5 micro mol/L in women, respectively. The prevalence of hyperhomocysteinemia (greater than 15.0 micro mol/L) was twice as high in rural compared with urban men (19.8% vs. 10.8%, p = 0.06) and women (6.6% vs. 3.4%, p = 0.26). Most study subjects (98%) had folate intakes that were less than the recommended 400 micro g/day. In women, 31% of those living in the urban area and 40% of those in the rural area had plasma folate concentrations of less than 6.8 nmol/L, an indicator of folate deficiency. In women, age-adjusted mean tHcy concentrations ( micro mol/L) were higher in the lowest compared with highest quintiles for dietary vitamin B(6) (9.9 vs. 5.4, p < 0.05), B(12) (9.2 vs. 4.9, p < 0.01), and folate (7.0 vs. 5.7, p = 0.87). Similar results were found for plasma B(12) (9.9 vs. 5.4, p < 0.01) and folate (10.5 vs. 5.0, p < 0.0001).

CONCLUSIONS

Residents of the rural area in Puriscal, Costa Rica have higher plasma concentrations of tHcy and lower intake of B vitamins, particularly in women. Because these characteristics are associated with high risk of cardiovascular disease, the efficacy of food fortification program in rural areas should be carefully addressed.

Intake of trans fatty acids and low-density lipoprotein size in a Costa Rican population

Intervention studies show that dietary composition altered low-density lipoprotein (LDL) particle size, but population studies are scarce, and the potential effects of trans fatty acids (FA) on LDL size are unknown. Trans FA intake has been associated with a more atherogenic lipid profile and increased coronary heart disease (CHD). We examined the association between dietary intake, including trans FA and LDL size, in 414 randomly selected subjects living in Puriscal, Costa Rica. Dietary intake was assessed by a validated food frequency questionnaire (FFQ). Women had larger LDL size (A) compared with men (263 v 261), and large LDL particles were correlated with increased intake (% energy) of protein (P =.005), animal fat (P =.041), trans FA (P <.0001), and decreased intake of carbohydrate (P =.052) in sex-, age-, and total energy intake-adjusted models. The correlation between trans FA intake and large LDL was significant in multivariate models that included dietary and nondietary factors; a 1% difference in trans FA was associated with a 2.44 A increase in LDL size (P =.004). In sum, it is possible that the effects of dietary factors, such as intake of trans FA on CHD are mediated through their effects on LDL size.

Frequent intake of tropical fruits that are rich in beta-cryptoxanthin is associated with higher plasma beta-cryptoxanthin concentrations in Costa Rican adolescents

Dietary tocopherols and carotenoids may play a role in preventing cancer and cardiovascular diseases. Because these may begin to develop during adolescence, dietary patterns during this period could influence long-term risk. The objective of this study was to examine the intake and plasma concentrations of the major carotenoids and tocopherols in 159 adolescents (mean +/- SD, 15.5 +/- 2.5 y old) living in Costa Rica. All participants completed a 135-item food-frequency questionnaire and provided a fasting blood sample. Carotenoid and tocopherol intakes were adjusted for total energy and plasma concentrations for total cholesterol. The relative abundance of carotenoids in the diet was similar to their distribution in plasma; lycopene was the most abundant, followed by beta-carotene and lutein + zeaxanthin. gamma-Tocopherol was more abundant than alpha-tocopherol in the diet, but alpha-tocopherol was approximately sevenfold higher in plasma. The highest diet-plasma correlations (adjusted for age, sex and body mass index) were 0.38 for beta-cryptoxanthin, 0.33 for gamma-tocopherol and 0.17 for lutein + zeaxanthin (all P < 0.05). All other correlations were r < 0.15. Papaya intake was the best food predictor of plasma beta-cryptoxanthin concentrations (r = 0.41). Subjects that frequently (> or =3/d) consumed tropical fruits with at least 50 micro g/100 g beta-cryptoxanthin (papaya, tangerine, orange and watermelon) had twofold the plasma beta-cryptoxanthin concentrations of those with intakes of <4/wk (P for trend = 0.0009). In sum, the diet-plasma carotenoid and tocopherol correlations were generally low in Costa Rican adolescents. Intakes of beta-cryptoxanthin and papaya, a tropical fruit frequently consumed in Latin America, were the best predictors of beta-cryptoxanthin concentrations in plasma.