Influence of vitamin D supplementation on bone mineral content, bone turnover markers, and fracture risk in South African schoolchildren: multicenter double-blind randomized placebo-controlled trial (ViDiKids).

Randomized controlled trials (RCTs) to determine the influence of vitamin D on BMC and fracture risk in children of Black African ancestry are lacking. We conducted a sub-study (n = 450) nested within a phase 3 RCT of weekly oral supplementation with 10 000 IU vitamin D3 vs placebo for 3 yr in HIV-uninfected Cape Town schoolchildren aged 6-11 yr. Outcomes were BMC at the whole body less head (WBLH) and LS and serum 25-hydroxyvitamin D3 (25(OH)D3), PTH, alkaline phosphatase, C-terminal telopeptide, and PINP. Incidence of fractures was a secondary outcome of the main trial (n = 1682). At baseline, mean serum 25(OH)D3 concentration was 70.0 nmol/L (SD 13.5), and 5.8% of participants had serum 25(OH)D3 concentrations <50 nmol/L. Among sub-study participants, end-trial serum 25(OH)D3 concentrations were higher for participants allocated to vitamin D vs placebo (adjusted mean difference [aMD] 39.9 nmol/L, 95% CI, 36.1 to 43.6) and serum PTH concentrations were lower (aMD -0.55 pmol/L, 95% CI, -0.94 to -0.17). However, no interarm differences were seen for WBLH BMC (aMD -8.0 g, 95% CI, -30.7 to 14.7) or LS BMC (aMD -0.3 g, 95% CI, -1.3 to 0.8) or serum concentrations of bone turnover markers. Fractures were rare among participants in the main trial randomized to vitamin D vs placebo (7/755 vs 10/758 attending at least 1 follow-up; adjusted odds ratio 0.70, 95% CI, 0.27 to 1.85). In conclusion, a 3-yr course of weekly oral vitamin D supplementation elevated serum 25(OH)D3 concentrations and suppressed serum PTH concentrations in HIV-uninfected South African schoolchildren of Black African ancestry but did not influence BMC or serum concentrations of bone turnover markers. Fracture incidence was low, limiting power to detect an effect of vitamin D on this outcome.

Vitamin D­the "sunshine vitamin"­is essential for helping the body to absorb calcium from the diet, which is laid down in bone to improve its strength. There is a lack of clinical trials testing whether vitamin D supplements can improve bone content of calcium and other minerals, or reduce risk of bone fractures (broken bones) in children of Black African ancestry. We therefore conducted such a study, recruiting 1682 schoolchildren aged 6­11 yr living in Cape Town, South Africa. We found that a weekly dose of 10 000 international units (250 micrograms) of vitamin D3, given by mouth for 3 yr, was effective in boosting vitamin D levels in trial participants who received it. However, this did not have any effect on bone content of calcium and other minerals. Relatively few children experienced a broken bone during the study, so we were unable to say with confidence whether or not vitamin D supplements might affect this outcome.

Determining classes of food items for health requirements and nutrition guidelines using Gaussian mixture models.

Introduction: The identification of classes of nutritionally similar food items is important for creating food exchange lists to meet health requirements and for informing nutrition guidelines and campaigns. Cluster analysis methods can assign food items into classes based on the similarity in their nutrient contents. Finite mixture models use probabilistic classification with the advantage of taking into account the uncertainty of class thresholds. Methods: This paper uses univariate Gaussian mixture models to determine the probabilistic classification of food items in the South African Food Composition Database (SAFCDB) based on nutrient content. Results: Classifying food items by animal protein, fatty acid, available carbohydrate, total fibre, sodium, iron, vitamin A, thiamin and riboflavin contents produced data-driven classes with differing means and estimates of variability and could be clearly ranked on a low to high nutrient contents scale. Classifying food items by their sodium content resulted in five classes with the class means ranging from 1.57 to 706.27 mg per 100 g. Four classes were identified based on available carbohydrate content with the highest carbohydrate class having a mean content of 59.15 g per 100 g. Food items clustered into two classes when examining their fatty acid content. Foods with a high iron content had a mean of 1.46 mg per 100 g and was one of three classes identified for iron. Classes containing nutrient-rich food items that exhibited extreme nutrient values were also identified for several vitamins and minerals. Discussion: The overlap between classes was evident and supports the use of probabilistic classification methods. Food items in each of the identified classes were comparable to allowed food lists developed for therapeutic diets. This data-driven ranking of nutritionally similar classes could be considered for diet planning for medical conditions and individuals with dietary restrictions.

Systematic Review of the Literature to Inform the Development of a South African Dietary Polyphenol Composition Database.

Comprehensively compiled dietary polyphenol data is required to compare polyphenol content between foods, calculate polyphenol intake and study its association with health and disease. The purpose of this review was to identify data on the presence and content of polyphenolic components in South African foods, with the aim of compiling the data into a database. An electronic literature search was conducted up until January 2020 using multiple databases. Additional literature was sourced from South African university repositories. A total of 7051 potentially eligible references were identified, of which 384 met the inclusion criteria. These studies provided information on food item name, geographical distribution, polyphenol type, quantity, and quantification method. Data for 1070 foods were identified, amounting to 4994 polyphenols. Spectrophotometry was the main method used for quantification of gross phenolic content in various assays such as total phenolic content (Folin-Ciocalteu assay), total flavonoid content (AlCl3 assay) and condensed tannin content (vanillin-HCl assay). Phenolic acids and flavonoids were the main polyphenol classes identified. This review highlights that South Africa has abundant information on the polyphenol content of foods, which could be utilised within a food composition database for the estimation of polyphenol intake for South Africa.

The Efficacy of Fish as an Early Complementary Food on the Linear Growth of Infants Aged 6-7 Months: A Randomised Controlled Trial.

Fish is a good animal-source protein for growth and development. The main objective of the study was to assess the efficacy of fish during the early complementary feeding period on infants' linear growth in the Samfya district of the Luapula Province of Zambia in 6 months randomised controlled trial. The study was conducted from April 2019 to January 2020. Infants aged 6-7 months (N = 238) were assigned to either the intervention (treatment) group or control (placebo) group to receive fish powder or sorghum powder, respectively. Participants were followed on a weekly basis to distribute the powder and record compliance/usage and any morbidities. Anthropometric measurements were taken monthly. A linear mixed-effects model showed that fish powder improved linear growth among infants over all the 6 months of the intervention period. The fish powder increased length-for-age z scores by 1.26 (95% CI: 0.94-1.57) and weight-for-age z score by 0.95 (95% CI 0.6-1.23). The addition of fish powder to the infant's usual food during the early complementary feeding improves the infant's linear growth outcome.

Statistical Methods for the Analysis of Food Composition Databases: A Review.

Evidence-based knowledge of the relationship between foods and nutrients is needed to inform dietary-based guidelines and policy. Proper and tailored statistical methods to analyse food composition databases (FCDBs) could assist in this regard. This review aims to collate the existing literature that used any statistical method to analyse FCDBs, to identify key trends and research gaps. The search strategy yielded 4238 references from electronic databases of which 24 fulfilled our inclusion criteria. Information on the objectives, statistical methods, and results was extracted. Statistical methods were mostly applied to group similar food items (37.5%). Other aims and objectives included determining associations between the nutrient content and known food characteristics (25.0%), determining nutrient co-occurrence (20.8%), evaluating nutrient changes over time (16.7%), and addressing the accuracy and completeness of databases (16.7%). Standard statistical tests (33.3%) were the most utilised followed by clustering (29.1%), other methods (16.7%), regression methods (12.5%), and dimension reduction techniques (8.3%). Nutrient data has unique characteristics such as correlated components, natural groupings, and a compositional nature. Statistical methods used for analysis need to account for this data structure. Our summary of the literature provides a reference for researchers looking to expand into this area.

Identifying Nutrient Patterns in South African Foods to Support National Nutrition Guidelines and Policies.

Food composition databases (FCDBs) provide the nutritional content of foods and are essential for developing nutrition guidance and effective intervention programs to improve nutrition of a population. In public and nutritional health research studies, FCDBs are used in the estimation of nutrient intake profiles at the population levels. However, such studies investigating nutrient co-occurrence and profile patterns within the African context are very rare. This study aimed to identify nutrient co-occurrence patterns within the South African FCDB (SAFCDB). A principal component analysis (PCA) was applied to 28 nutrients and 971 foods in the South African FCDB to determine compositionally similar food items. A second principal component analysis was applied to the food items for validation. Eight nutrient patterns (NPs) explaining 73.4% of the nutrient variation among foods were identified: (1) high magnesium and manganese; (2) high copper and vitamin B12; (3) high animal protein, niacin, and vitamin B6; (4) high fatty acids and vitamin E; (5) high calcium, phosphorous and sodium; (6) low moisture and high available carbohydrate; (7) high cholesterol and vitamin D; and (8) low zinc and high vitamin C. Similar food patterns (FPs) were identified from a PCA on food items, yielding subgroups such as dark-green, leafy vegetables and, orange-coloured fruit and vegetables. One food pattern was associated with high sodium levels and contained bread, processed meat and seafood, canned vegetables, and sauces. The data-driven nutrient and food patterns found in this study were consistent with and support the South African food-based dietary guidelines and the national salt regulations.

Prevalence of glutamine deficiency in ICU patients: a cross-sectional analytical study.

BACKGROUND: Not only is glutamine deficiency an independent predictor of mortality in intensive care unit (ICU) patients, but glutamine supplementation is also recommended for its proven outcome benefits. However, recent data suggest that early glutamine supplementation in certain patient groups increase mortality. The aim of this study was to investigate plasma glutamine levels of adult ICU patients in the South African setting and to determine relationships between glutamine levels, gender, diagnostic categories and selected inflammatory markers. The data from this study will be used as baseline measurement to support a large scale study that will be undertaken in the South African ICU population. METHODS: This cross-sectional, analytical study included 60 mixed adult ICU patients within 24 h post ICU admission. Plasma glutamine levels were determined on admission. The relationship between glutamine levels, Interleukin-6 (IL-6) and C-reactive protein (CRP); as well as gender- and diagnosis-related differences in glutamine levels were also investigated. A non-parametric ROC curve was computed to determine the CRP concentration cut-off point above which glutamine becomes deficient. RESULTS: The median plasma glutamine level (497 µmol/L) was in the normal range; however, 38.3 % (n = 23) of patients had deficient (<420 µmol/L) and 6.7 % (n = 4) had supra-normal glutamine levels (>930 µmol/L). No significant difference could be detected between glutamine levels and gender or diagnosis categories as a group. When only the medical and surgical categories were compared, the median plasma glutamine level of the medical patients were significantly lower than that of the surgical patients (p = 0.042). Glutamine showed inverse associations with CRP levels (r = -0.44, p < 0.05) and IL-6 concentrations (r = -0.23, p = 0.08). A CRP cut-off value of 95.5 mg/L was determined above which glutamine levels became deficient. CONCLUSIONS: About a third of patients (38 %) were glutamine deficient on admission to ICU, whereas some presented with supra-normal levels. While glutamine levels correlated inversely with inflammatory markers, and a CRP value of above 95.5 mg/L indicated potential glutamine deficiency, the clinical application of this finding needs further investigation.

Effects of a multi-micronutrient-fortified beverage, with and without sugar, on growth and cognition in South African schoolchildren: a randomised, double-blind, controlled intervention.

Little is known about the effects of combined micronutrient and sugar consumption on growth and cognition. In the present study, we investigated the effects of micronutrients and sugar, alone and in combination, in a beverage on growth and cognition in schoolchildren. In a 2 × 2 factorial design, children (n 414, 6-11 years) were randomly allocated to consume beverages containing (1) micronutrients with sugar, (2) micronutrients with a non-nutritive sweetener, (3) no micronutrients with sugar or (4) no micronutrients with a non-nutritive sweetener for 8.5 months. Growth was assessed and cognition was tested using the Kaufman Assessment Battery for Children version II (KABC-II) subtests and the Hopkins Verbal Learning Test (HVLT). Micronutrients decreased the OR for Fe deficiency at the endpoint (OR 0.19; 95% CI 0.07, 0.53). Micronutrients increased KABC Atlantis (intervention effect: 0.76; 95% CI 0.10, 1.42) and HVLT Discrimination Index (1.00; 95% CI 0.01, 2.00) scores. Sugar increased KABC Atlantis (0.71; 95% CI 0.05, 1.37) and Rover (0.72; 95% CI 0.08, 1.35) scores and HVLT Recall 3 (0.94; 95% CI 0.15, 1.72). Significant micronutrient × sugar interaction effects on the Atlantis, Number recall, Rover and Discrimination Index scores indicated that micronutrients and sugar in combination attenuated the beneficial effects of micronutrients or sugar alone. Micronutrients or sugar alone had a lowering effect on weight-for-age z-scores relative to controls (micronutrients - 0.08; 95% CI - 0.15, - 0.01; sugar - 0.07; 95% CI - 0.14, - 0.002), but in combination, this effect was attenuated. The beverages with micronutrients or added sugar alone had a beneficial effect on cognition, which was attenuated when provided in combination.

Field-testing of guidance on the appropriate labelling of processed complementary foods for infants and young children in South Africa.

There is a lack of formal guidance from international normative bodies on the appropriate marketing of processed complementary foods. Such guidance is necessary to protect and promote optimal infant and young child feeding practices. The aim of this study was to field-test, in South Africa, the interim guidance provided by the Maternal, Infant and Young Child Nutrition Working Group's Draft Guide for Marketing Complementary Foods as a potential tool for use by manufacturers and national governments for guiding the appropriate labelling (as a subset of appropriate marketing practices) of complementary foods. This guidance was used to develop a checklist of questions and criteria for each possible answer, which was tested using a comprehensive database of labels from products purchased in South Africa from June to August 2011. One hundred and sixty product labels of 35 manufacturers were analysed, none of which complied with all checklist criteria. Fifty-six (35%) labels did not provide an appropriate age of introduction while 37 (23%) used images of infants appearing younger than 6 months. Nineteen (12%) labels suggested a daily ration too large for a breastfed child, and 32 (20%) potentially promote the manufacturer's infant formula. Only 58 (36%) labels were easy to read. The majority (69% and 92%) of labels provided instructions for safe and appropriate preparation/use and storage, respectively. The Draft Guide for Marketing Complementary Foods was found to be a useful tool for guiding the appropriate labelling of complementary foods, although some changes and additions are recommended to improve understanding, ease of use and to minimise the subjective interpretation of the guidance.

Association between iron status and white blood cell counts in African schoolchildren of the North-West Province, South Africa.

Iron deficiency with or without anemia is associated with increased susceptibility to infection owing to impaired immune function; this study aimed to examine the associations between markers of iron status and white blood cell counts in African schoolchildren. This cross-sectional study is part of the larger BeForMi study done in the North-West province of South Africa. A total of 556 African schoolchildren (aged 7-10 years) were recruited from the three schools participating in the BeForMi multiple micronutrient intervention study. Demographic information of the children was obtained from their parents/caregivers/guardians in the language of choice using validated questionnaires. Anthropometric indices (weight and height), iron status parameters, hematological parameters (hemoglobin (Hb), red blood cell count (RBC), total and differential white blood cell counts) were measured using standard procedures. No significant gender differences were observed in most of the iron markers and hematological parameters except in C-reactive protein (CRP) (p=0.004) and eosinophils (p=0.042) which were higher in boys while RBC (p=0.018) and Hb (p=0.023) levels were higher in girls. No relationships were observed between the different iron markers and differential white blood cell counts. A positive correlation was observed between serum ferritin (SF) and CRP in girls only (r=0.336, p<0.01), and a positive correlation between SF and mean cell volume (MCV) in boys only (r=0.197, p<0.01). In both genders, no correlations were observed between the different iron markers and the differential white blood cell counts. The study revealed no associations between iron status and differential white blood cell counts in children that participated in the BeForMi study calling for more studies to be done in the area of the significance of iron supplementation in healthy children.

Polyunsaturated fatty acid intake is adversely related to liver function in HIV-infected subjects: the THUSA study.

BACKGROUND: Dietary fat intake in the South African population is increasing. This population also has a high prevalence of HIV infection. However, information about metabolic effects of dietary fatty acids on HIV-infected subjects is lacking. OBJECTIVE: Our objective was to investigate the relation between dietary fatty acid intake and liver function in HIV-infected compared with HIV-uninfected subjects. DESIGN: This cross-sectional epidemiologic survey included a representative sample of 1854 apparently healthy black volunteers aged > or =15 y, who were recruited from 37 randomly selected sites throughout the North West province of South Africa. Data from 216 asymptomatic HIV-infected and 1604 HIV-uninfected subjects were used. RESULTS: Intakes of polyunsaturated fatty acids (PUFAs), linoleic acid (n-6), and the ratio of PUFAs to saturated fatty acids (SFAs) were positively associated with all the liver enzymes measured in HIV-infected subjects (R = 0.16-0.65). Most of these R values differed significantly from the R values for HIV-uninfected subjects. No associations were seen between liver enzymes and intakes of SFAs and monounsaturated fatty acids. Vitamin E intake was positively associated with serum gamma-glutamyl transpeptidase (R = 0.23), alanine aminotransferase (R = 0.37), and aspartate aminotransferase (R = 0.58) in HIV-infected subjects; these correlations differed significantly from those of the HIV-uninfected subjects because PUFA sources are the main carriers of vitamin E. CONCLUSIONS: The results suggest that n-6 PUFA intakes may be related to liver damage in these HIV-infected asymptomatic subjects. The reasons or mechanisms responsible are not clear, and further research is necessary to determine the optimal safe amounts for intake of n-6 PUFAs by HIV-infected subjects, especially in countries with traditionally high intakes of n-6 PUFA-rich vegetable oils.