There is increasing interest in vitamin D and its possible health effects. The aims of the present overview are to summarise the research on common diseases for which there is substantial evidence on vitamin D, identify diseases where vitamin D may be beneficial and discuss the public health implications of these findings.

Literature search of PubMed for the years 2000 to 2010 to identify cohort studies with baseline measures of 25-hydroxyvitamin D (25(OH)D) and randomised controlled trials (RCT) of vitamin D supplementation in relation to fractures, colorectal cancer, CVD and all-cause mortality. Risk ratios of disease from comparisons between 25(OH)D quantiles in these studies were summarised using RevMan software version 5·1 (The Nordic Cochrane Centre, Copenhagen).

Community-based samples recruited into cohort studies from many countries.

Older men and women, mostly above 50 years of age.

When comparing the lowest 25(OH)D category with the highest (or reference), the pooled risk ratio (95 % CI) was: 1·34 (1·13, 1·59) for fractures from nine studies; 1·59 (1·30, 1·95) for colorectal cancer from nine studies; 1·35 (1·17, 1·56) for CVD from twelve studies; and 1·42 (1·23, 1·63) for all-cause mortality from twelve studies.

Cohort studies show that baseline 25(OH)D levels predict increased risk of fractures, colorectal cancer, CVD and all-cause mortality. These associations are weak and could be explained by confounding variables such as obesity and physical activity. Because of their potential public health significance, RCT using vitamin D doses ≥50 μg/d are required to determine whether vitamin D protects against these diseases.

To determine the impact of facility-based semi-intensive and home-based intensive counselling in improving exclusive breast-feeding (EBF) in a low-resource urban setting in Kenya.

A cluster randomized controlled trial in which nine villages were assigned on a 1:1:1 ratio, by computer, to two intervention groups and a control group. The home-based intensive counselling group (HBICG) received seven counselling sessions at home by trained peers, one prenatally and six postnatally. The facility-based semi-intensive counselling group (FBSICG) received only one counselling session prenatally. The control group (CG) received no counselling from the research team. Information on infant feeding practices was collected monthly for 6 months after delivery. The data-gathering team was blinded to the intervention allocation. The outcome was EBF prevalence at 6 months.

Kibera slum, Nairobi.

A total of 360 HIV-negative women, 34–36 weeks pregnant, were selected from an antenatal clinic in Kibera; 120 per study group.

Of the 360 women enrolled, 265 completed the study and were included in the analysis (CG n 89; FBSICG n 87; HBICG n 89). Analysis was by intention to treat. The prevalence of EBF at 6 months was 23·6 % in HBICG, 9·2 % in FBSICG and 5·6 % in CG. HBICG mothers had four times increased likelihood to practise EBF compared with those in the CG (adjusted relative risk = 4·01; 95 % CI 2·30, 7·01; P = 0·001). There was no significant difference between EBF rates in FBSICG and CG.

EBF can be promoted in low socio-economic conditions using home-based intensive counselling. One session of facility-based counselling is not sufficient to sustain EBF.

To study consumer knowledge and use of food labels.

A cross-sectional study employing both quantitative and qualitative methods. Intercept interviews were conducted with 1832 consumers at supermarket sites selected using a stratified random sampling procedure. This information was triangulated with twenty-one focus group discussions.

New Delhi and Hyderabad, two metro-cities from north and south India.

Adolescent (10–19 years), adult (20–59 years) and elderly (≥60 years) consumers.

While the national urban literacy rate is 84 %, about 99 % of the study participants were educated. About 45 % reported that they buy pre-packaged foods once weekly and about a fifth buy them every day. Taste, quality, convenience and ease of use are the main reasons for buying pre-packaged foods. Although 90 % of consumers across the age groups read food labels, the majority (81 %) looked only for the manufacturing date or expiry/best before date. Of those who read labels, only a third checked nutrition information and ingredients. Nutrient information on labels was not often read because most consumers either lacked nutrition knowledge or found the information too technical to understand. About 60 % read quality symbols. A positive association was found between education level and checking various aspects of food labels. Women and girls concerned about ‘fat’ and ‘sugar’ intake read the nutrition facts panel.

The intention of promoting healthy food choices through use of food labels is not being completely met. Since a majority of people found it difficult to comprehend nutrition information, there is a need to take up educational activities and/or introduce new forms of labelling.

The present study aimed to investigate the determinants of overweight and obesity among 6- to 11-year-old schoolchildren in Rasht, Iran.

Cross-sectional survey. Data on age, weekly frequency of skipping breakfast, physical activity and hours of television viewing were collected. Information on birth weight, parental age, parental educational levels, parental weight and height, and mother’s employment status were gathered through self-administrated questionnaires given to the parents.

Elementary schools in Rasht.

A total of 6635 children (3551 boys and 3084 girls) attending elementary schools in Rasht were studied.

The overall prevalence of overweight was 11·5 % and 15·0 % for boys and girls, respectively; while the overall prevalence of obesity was 5·0 % and 5·9 %, respectively. Children with more educated mothers had a higher prevalence of overweight than children with less educated mothers. Logistic regression analysis showed that children with overweight/obese parents, children with more educated mothers and children who often skipped breakfast were more prone to overweight and obesity.

These data suggest that overweight and obesity is a public health concern in this age group in Rasht. The observed sex and social differences in the prevalence of overweight and obesity call for policy makers’ attention.

To explore knowledge, attitudes and behaviours regarding caloric soft drinks in a group of young adults attending university and to identify opportunities for a health promotion intervention aimed at reducing consumption.

In-depth, semi-structured focus groups segmented by gender.

Sydney, Australia.

Undergraduate University of Sydney students aged 18–30 years (n 35).

Social and environmental cues, intrinsic qualities of beverages and personal health beliefs were identified as important influences on consumption. Social cues included settings in which alcohol is usually consumed, socialising with friends, and family influences. Environmental cues included purchasing of fast foods, and ready availability, preferential pricing and promotion of caloric beverages. Reinforcing intrinsic qualities of caloric soft drinks included taste, sugar and caffeine content, and their association with treats and rewards. Major gender differences as well as variations in individual readiness for behaviour change were observed. Raising awareness of the sugar content of various beverages and the potential health impacts associated with their consumption was considered important.

The findings provide new insights with important implications for policy and practice, and suggest that there is considerable scope for promoting awareness in this group. Carefully designed social marketing campaigns highlighting the health issues and addressing social and environmental cues relating to caloric soft drink consumption are required. There is a need for gender-differentiated intervention programmes which are both informational and appealing to young adults. Further research is warranted, particularly to investigate beverage consumption relating to fast-food meal deals and young adults’ consumption patterns in more depth.

To determine the prevalence of vitamin A deficiency, infection and adequacy of vitamin A intakes among Zambian children, and the contribution of dietary vitamin A and infection to vitamin A status.

A cross-sectional survey of vitamin A intakes by the 24 h recall method, vitamin A status by plasma retinol and the modified relative dose-response test, and infection by acute-phase proteins.

Rural communities in Central and Eastern Provinces of Zambia.

Children 2–5 years of age.

The prevalence of vitamin A deficiency was 56 % by plasma retinol, 48 % with infection-adjusted plasma retinol and 22 % by the modified relative dose-response test. The majority of children (61 %) had a current infection. Vitamin A intakes were relatively high (331 to 585 μg retinol activity equivalents/d in the harvest/early post-harvest and late post-harvest seasons, respectively) and the prevalence of inadequate intakes was <1 % when compared with the Estimated Average Requirement (210 and 275 μg retinol activity equivalents/d for children aged 1–3 and 4–8 years, respectively). Elevated α-1-acid glycoprotein was negatively associated with plasma retinol (P < 0·0 0 1) and vitamin A intake was positively associated with plasma retinol (P < 0·05), but only when estimated assuming a 26:1 retinol equivalence for provitamin A from green and yellow vegetables.

Infection and vitamin A intakes were significant determinants of plasma retinol. We cannot conclude which indicator more accurately represents the true vitamin A status of the population. Reasons for the persistent high prevalence of vitamin A deficiency in the presence of adequate vitamin A intakes are unclear, but the high rates of infection may play a role.

To examine associations of biomarkers of nutrient intake with overall diet quality.

A convenience sample of 102 healthy postmenopausal women in Seattle, Washington (USA).

Participants attended a study centre where they provided fasting blood specimens and completed a 122-item validated food-frequency questionnaire (FFQ). Data from the FFQ were used to calculate Diet Quality Index (DQI) scores and categorise women as having diets of excellent, good, fair or poor quality. The blood specimens were analysed for nine phospholipid fatty acids (as percentage of total) and serum concentrations of vitamin C, α-tocopherol, γ-tocopherol, vitamin B12, folate and six carotenoids. Multivariate linear regression was used to model associations of the nutrient biomarkers with DQI scores.

Compared with women with poor-quality diets, women with excellent diets, as measured by the DQI, had higher plasma concentrations of vitamin C (P for trend = 0.01), α-tocopherol (P for trend = 0.02) and β-cryptoxanthin (P for trend = 0.03). Women with excellent diets also had lower proportions of plasma phospholipid fatty acids of two potentially atherogenic fatty acids: stearic acid (P for trend = 0.01) and behenic acid (P for trend = 0.03). A group of six biomarkers explained a moderate proportion of the total variability in DQI scores (36%).

These objective measures of dietary intake support the use of the DQI as a useful tool to measure dietary patterns.

To better understand low-income adults’ attitudes towards participating in farmers’ markets, community-supported agriculture (CSA) and nutrition education programming.

Focus groups were held with a diverse sample of adults. Interviews were transcribed verbatim and analysed using thematic analysis.

Three affordable housing communities in Washington, DC, USA.

Participants included twenty-eight residents of the three affordable housing communities.

Four major themes emerged across groups, along with several sub-themes within each theme. These included: (i) perceptions of farmers’ markets (benefits, barriers, current participation and knowledge); (ii) perceptions of CSA (benefits, barriers and questions/concerns); (iii) need/interest in additional programming (nutrition education, non-nutrition education, qualities of programming and perceived barriers); and (iv) current health knowledge and behaviours (dietary behaviours, health recommendations and health concerns).

Adults living in urban, affordable housing communities desire access to healthy foods, but are limited by cost. Programmes could have a higher likelihood of success if they accept benefits like SNAP (the Supplemental Nutrition Assistance Program), are heavily marketed and incorporate culturally relevant nutrition education components.

To systematically review prospective cohort studies about the association between dietary patterns and type 2 diabetes mellitus (T2DM) incidence, and to quantify the effects using a meta-analysis.

Databases such as PubMed, ISI Web of Science, SCOPUS and Google Scholar were searched up to 15 January 2015. Cohort studies which tried to examine the association between empirically derived dietary patterns and incident T2DM were selected. The relative risks (RR) and their 95 % confidence intervals for diabetes among participants with highest v. lowest adherence to derived dietary patterns were incorporated into meta-analysis using random-effects models.

Ten studies (n 404 528) were enrolled in the systematic review and meta-analysis; our analysis revealed that adherence to the ‘healthy’ dietary patterns significantly reduced the risk of T2DM (RR=0·86; 95 % CI 0·82, 0·90), while the ‘unhealthy’ dietary patterns adversely affected diabetes risk (RR=1·30; 95 % CI 1·18, 1·43). Subgroup analysis showed that unhealthy dietary patterns in which foods with high phytochemical content were also loaded did not significantly increase T2DM risk (RR=1·06; 95 % CI 0·87, 1·30).

‘Healthy’ dietary patterns containing vegetables, fruits and whole grains can lower diabetes risk by 14 %. Consuming higher amounts of red and processed meats, high-fat dairy and refined grains in the context of ‘unhealthy’ dietary patterns will increase diabetes risk by 30 %; while including foods with high phytochemical content in these patterns can modify this effect.

To analyse the association between food store type and the consumption of ultra-processed products in Brazil.

Data from the 2008–2009 Household Budget Survey involving a probabilistic sample of 55 970 Brazilian households. Food stores were grouped into nine categories. Foods and drinks were grouped according to characteristics of food processing. The contribution of each food store type to the total energy acquired from each food processing group, and according to quintiles of consumption of ultra-processed products, was estimated. Exploratory factor analysis was conducted to identify a pattern of food store usage. Linear regression models were performed to estimate the relationship between the purchase pattern and the consumption of ultra-processed products.

In line with their larger market share, supermarkets accounted for 59 % of total energy and participated most in acquisition for three food groups, with emphasis on ultra-processed products (60·4 % of energy). The participation of supermarkets in total purchase tended to increase in populations with higher consumption of ultra-processed products, while the participation of small markets and small producers tended to decrease. The purchase pattern characterized by use of traditional retail (street fairs and vendors, small markets, small farmers, butcheries) was associated with a smaller consumption of ultra-processed products.

Food policies and interventions aiming to reduce the consumption of ultra-processed products should consider the influence of supermarkets on the consumption of these products. A purchase pattern based on traditional retail constitutes an important tool for promoting healthy eating in Brazil.

The present study examined the association between unemployment and household food insecurity during the 2007–2009 economic recession in the USA.

Longitudinal survey of the Survey of Income and Program Participation (SIPP; 2008–2011). Food insecurity was measured by five questions excerpted from an eighteen-item Food Security Scale. Unemployment was measured by a dichotomous indicator, the number of job losses and the total duration of all episodes in the observation period.

As nationally representative data, the SIPP interviewed respondents in multiple waves with a time interval of four months.

The study created two analytic samples including working-age household heads employed at the beginning of the observation period. The size of the two samples was 14 417 and 13 080.

Unemployment was positively associated with food insecurity (OR=1·55; 95 % CI 1·32, 1·83; P<0·001). Similar results were obtained when the analysis controlled for food insecurity status measured before unemployment (OR=1·54; 95 % CI 1·27, 1·88; P<0·001). For households with the same duration of unemployment, one more episode of unemployment increased the odds of food insecurity by 8 % (OR=1·08; 95 % CI 1·00, 1·18; P<0·001).

More in-depth understanding of the relationship between unemployment and food insecurity is useful to better identify and serve the at-risk population. Connecting unemployment assistance closely to nutrition assistance could lower the prevalence of food insecurity among unemployed households. Public policy should better account for both episodes and duration of unemployment to reduce food insecurity.

To assess the nutritional status of Tunisian adolescents and associated factors.

A cross-sectional study based on a national stratified random cluster sample.

In all, 1295 boys and 1577 girls aged 15–19 years, of whom 28·4 % had already left school. Socio-economic characteristics of the parents, anthropometric measurements, food behaviours and physical activity of the adolescents were recorded during home visits.

Prevalence of underweight, overweight and obesity (WHO/National Center for Health Statistics reference) were, respectively, 8·1 %, 17·4 % and 4·1 % among boys and 1·3 %, 20·7 % and 4·4 % among girls; abdominal obesity was highly prevalent among both sexes. Prevalence of overweight differed by region (from 11·5 % to 22·2 %) and was higher in urban v. rural areas for males (21·7 % v. 10·4 %) but not for females (21·7 % v. 19·2 %). These differences were partially mediated by socio-economic and lifestyle factors for males. For females, influence of cultural factors is hypothesised. In rural areas, overweight was more prevalent among boys of higher economic level households, having a working mother or a sedentary lifestyle; for girls, prevalence increased with the level of education of the mother. In urban areas, prevalence of overweight was related to eating habits: it was higher for boys with irregular snacking habits and for girls skipping daily meals. Urban girls having left school were also more overweight.

Overweight and abdominal obesity in late adolescence have become a true public health problem in Tunisia with the combined effects of cultural tradition for girls in rural areas, and of rapid economic development for boys and girls in cities.

To examine intakes and variety of fruit and vegetables consumed by Australian young adults, also assessing differences by meal occasion and sociodemographic characteristics.

Secondary analysis of cross-sectional 24 h recall data collected through the 2011–12 National Nutrition and Physical Activity Survey. Crude means and proportions consuming fruits and vegetables were calculated. Pearson χ2 tests, Kruskal–Wallis analyses and linear regression models were used to assess differences in mean intakes by age, BMI and sociodemographic variables. The variety eaten was determined based on the number of fruit and vegetable subgroups consumed.

Representative sample of metropolitan and rural areas across Australia.

Respondents aged 18–34 years were included (n 2397).

Mean daily intake of fruit (128 g/0·9 servings) and vegetables (205 g/2·7 servings) was lower than the minimum recommended intake set at 2 and 5 servings, respectively. Age was positively associated with fruit and vegetable intake (P=0·002, P<0·001), with 18–24-year-olds reporting the poorest vegetable variety compared with 25–29- and 30–34-year-olds (P=0·002). When controlling for total energy, males consumed less vegetables than females (P=0·002). A large proportion of the 15 % of respondents who consumed adequate amounts of fruits and vegetables on the day prior to the survey reported intake across all meal occasions (P<0·001).

Fruit and vegetable intake is suboptimal among Australian young adults. An age-appropriate campaign is recommended to target increased consumption, particularly for those aged 18–24 years, with opportunity to promote increased variety and consumption across the day.

Most research on diet and exercise has focused on these health behaviours as proximate causes of disease, rather than examine the context of how diet and exercise are developed and maintained. This study examined religion and social support in relationship to fat intake and physical activity.

Data from surveys of 546 adults aged 17–91 years, residing in one upstate New York county, were analysed.

Most relationships between the multiple facets of religion, fat intake and physical activity were not statistically significant. After controlling for demographics and social support, Conservative Protestant women and women specifying an ‘Other’ religious affiliation reported higher fat intakes than did Catholic women. There were no relationships between religion and fat intake in men. In women, religious commitment was associated with greater moderate and vigorous physical activity, whereas in men, divine social support was associated with greater moderate physical activity. Social support did not substantially change the magnitude of the relationships between religion, diet and physical activity.

Overall, there were few relationships between religion, fat intake and physical activity, suggesting that in contemporary US society religion may play a small role in the context of how diet and exercise are developed and maintained. The limited range of religiosity in the sample, however, may have underestimated the role of religion. Significant relationships between religion and physical activity in women suggest that further research is needed to more clearly delineate religion's relationship with health behaviours.

To simultaneously identify consumer segments based on individual-level consumption and community-level food retail environment data and to investigate whether the segments are associated with BMI and dietary knowledge in China.

A multilevel latent class cluster model was applied to identify consumer segments based not only on their individual preferences for fast food, salty snack foods, and soft drinks and sugared fruit drinks, but also on the food retail environment at the community level.

The data came from the China Health and Nutrition Survey (CHNS) conducted in 2006 and two questionnaires for adults and communities were used.

A total sample of 9788 adults living in 218 communities participated in the CHNS.

We successfully identified four consumer segments. These four segments were embedded in two types of food retail environment: the saturated food retail environment and the deprived food retail environment. A three-factor solution was found for consumers’ dietary knowledge. The four consumer segments were highly associated with consumers’ dietary knowledge and a number of sociodemographic variables.

The widespread discussion about the relationships between fast-food consumption and overweight/obesity is irrelevant for Chinese segments that do not have access to fast food. Factors that are most associated with segments with a higher BMI are consumers’ (incorrect) dietary knowledge, the food retail environment and sociodemographics. The results provide valuable insight for policy interventions on reducing overweight/obesity in China. This study also indicates that despite the breathtaking changes in modern China, the impact of ‘obesogenic’ environments should not be assessed too strictly from a ‘Western’ perspective.

Obesity is considered a major public health issue in most developed countries nowadays. This paper provides an overview of current population data available in Spain and the approach to develop preventive strategies in the country.

Review of population data available is based on individually measured weight and height as well as determinants. On this basis, the approach used in the country to develop preventive strategies is discussed.

According to the DORICA study, the prevalence of obesity (BMI ≥30 kg m−2) is 15.5% in Spanish adults aged 25–60 years (13.2% in men and 17.5% in women). Obesity rates are higher among women aged 45 years and older, low social class, living in semi-urban places. Population estimates for the prevalence of obesity in Spanish children and young people based on the enKid study are 13.9% for the whole group. In this study, overweight and obesity is related to absence of breastfeeding, low consumption of fruit and vegetables, high consumption of cakes, buns, softdrinks and butchery products, low physical activity levels and a positive association with time spent watching TV.

In 2005, the Spanish Ministry of Health jointly with the Spanish Agency for Food Safety and Nutrition launched the multifaceted NAOS strategy for nutrition, physical activity and the prevention of obesity. The important role of the family and the school setting as well as the responsibility of the Health Administration and Pediatric Care in the prevention of obesity is highlighted in the document. The need for environmental actions is recognised. The PERSEO programme, a multicomponent school-based intervention project is part of the strategy currently in place.

Obesity is a public health issue in Spain. A national multifaceted strategy was launched to counteract the problem. Environmental and policy actions are a priority. Young children and their families are among the main target groups.

To document the scale-up of India's Adolescent Girls’ Anaemia Control Programme following a knowledge-centred framework for scaling up nutrition interventions and to identify the critical elements of and lessons learned from a decade of programme experience for the control of anaemia in adolescent girls.

We reviewed all articles, programme and project reports, and baseline and endline assessments published between 1995 and 2012 regarding the control of anaemia through intermittent iron and folic acid supplementation; key programme specialists and managers were interviewed to complete or verify information wherever needed.

India.

Adolescent girls.

The scale-up of India's Adolescent Girls’ Anaemia Control Programme followed a knowledge-centred programme cycle comprising five phases: Evidence, Innovation, Evaluation, Replication and Universalization. By the end of 2011, the programme was being rolled out in thirteen states and was reaching 27·6 million adolescent girls of whom 16·3 million were school-going girls and 11·3 million were out-of-school girls. Building on the critical elements of and lessons learned from the programme, the Government of India launched in 2012 the national Weekly Iron and Folic Acid Supplementation (WIFS) programme to universalize the benefits of anaemia control to the overall population of Indian adolescents.

The Adolescent Girls’ Anaemia Control Programme in India provides a good example of how a knowledge-centred approach can successfully guide the scaling up of public health nutrition interventions and facilitate intersectoral convergence among different government departments and development partners to break the inter-generational cycle of undernutrition and deprivation.