There is a need to address cultural beliefs and parenting practices regarding childhood obesity to design effective weight-control programmes for overweight/obese US Latino children. The purpose of the current study was to explore cultural beliefs about children’s weight, understand parent perceptions on feeding their children, and explore barriers that interfere with a healthy lifestyle.

Four focus groups were conducted in Spanish with forty-one Latino mothers of elementary school-age children from San Diego County, California between April and May 2011. Cultural viewpoints about overweight status among children and barriers to leading a healthy lifestyle were explored. Focus group discussions were analysed based on a priori and emergent themes.

Three themes were identified: (i) mothers’ cultural beliefs about health that are barriers to family health; (ii) mothers as primary caretakers of their family’s health; and (iii) attitudes about targeting children’s weight. Mothers acknowledged the idea that ‘chubby is better’ is a misperception, yet having a ‘chubby’ child was preferred and even accepted. Mothers described fatalistic beliefs that contradicted existing knowledge of chronic disease and daily demands of Western culture as barriers to practising healthy behaviours in the home as the family caretaker.

These findings may be used to inform more culturally appropriate research to address US Latino health. Increasing awareness of cultural beliefs and daily circumstance could help to address obesity more directly and thereby overcome some of the potential underlying barriers that might exist when involving the Latino immigrant families in obesity treatment and prevention.

Owing to modern lifestyles, individuals are dependent on out-of-home eating. The catering sector can have a pivotal role in influencing our food choices. The objective of the present study was to examine the impact of a structured catering initiative on food choices in a public sector workplace setting.

A cross-sectional comparison study in two hospitals, one of which had implemented a catering initiative designed to provide nutritious food while reducing sugar, fat and salt intakes.

Two public sector hospitals in Cork, Ireland.

A total of 100 random participants aged 18–64 years (fifty intervention, fifty non-intervention) who consumed at least one main meal in the hospital staff canteen daily. Each respondent was asked to complete one anonymous 24 h dietary recall and questionnaire. Food and nutrient analysis was conducted using WISP (Weighed Intake Software Program).

Reported mean intakes of total sugars (P < 0·001), total fat (P < 0·000), saturated fat (P < 0·000) and salt (P < 0·046) were significantly lower in the intervention hospital when adjusted for age and gender. In the intervention hospital, 72 % of respondents, compared with 42 % in the non-intervention hospital, complied with the recommended under-3 daily servings of food high in fat and sugar (P < 0·005). In the intervention hospital, 43 % of respondents exceeded the recommended salt intake of 4–6 g/d, compared with 57 % in the non-intervention hospital.

Structured catering initiatives in the workplace are a potentially important option in the promotion of healthy food choices. Targeted public health programmes and health policy changes are needed to motivate caterers in the public sector and other industries to develop interventions that promote a healthy diet.

To study the associations between home food availability and dietary patterns among pre-school children.

Cross-sectional study in which parents of the participating children filled in an FFQ and reported how often they had certain foods in their homes. We derived dietary pattern scores using principal component analysis, and composite scores describing the availability of fruits and vegetables as well as sugar-enriched foods in the home were created for each participant. We used multilevel models to investigate the associations between availability and dietary pattern scores.

The DAGIS study, Finland.

The participants were 864 Finnish 3–6-year-old children recruited from sixty-six pre-schools. The analyses included 711 children with sufficient data.

We identified three dietary patterns explaining 16·7 % of the variance. The patterns were named ‘sweets-and-treats’ (high loadings of e.g. sweet biscuits, chocolate, ice cream), ‘health-conscious’ (high loadings of e.g. nuts, natural yoghurt, berries) and ‘vegetables-and-processed meats’ (high loadings of e.g. vegetables, cold cuts, fruit). In multivariate models, the availability of fruits and vegetables was inversely associated with the sweets-and-treats pattern (β=−0·05, P<0·01) and positively associated with the health-conscious (β=0·07, P<0·01) and vegetables-and-processed meats patterns (β=0·06, P<0·01). The availability of sugar-enriched foods was positively associated with the sweets-and-treats pattern (β=0·10, P<0·01) and inversely associated with the health-conscious pattern (β=−0·03, P<0·01).

Considering dietary patterns, the availability of sugar-enriched foods in the home seems to have a stronger role than that of fruits and vegetables. Parents should restrict the availability of unhealthy foods in the home.

To explore multiple methods of calculating diet diversity scores (DDS) to maximize associations with predicted dietary micronutrient adequacy among schoolchildren in rural Kenya.

Up to three 24 h recall interviews were administered for each child for a total of 1544 d of intake from all schoolchildren. Daily amounts of food consumed were assigned to one of eight food groups. Five DDS were developed based on various minimum intake amounts from each food group: (i) 1 g; (ii) 15 g; (iii) a variable minimum based on the content of a target nutrient for each group; (iv) the median intake level for each group; and (v) the 90th percentile intake level for each group. A diet was assigned 1 point towards the daily DDS if the food group intake was above the defined minimum level. Five scores were calculated for each child, and bivariate longitudinal random-effects models were used to assess the correlation between each DDS and the mean probability of adequacy for fourteen nutrients.

Embu District, Kenya.

Schoolchildren (n 529), mean age 7·00 (sd 1·41) years.

Only DDS based on a 15 g minimum and DDS based on nutrient content were significantly associated with mean probability of adequacy after adjusting for energy intake (0·21 and 0·41, respectively).

A DDS using minimum intakes based on nutrients contributed by a food group best predicted nutrient adequacy in this population. These analyses contribute to the continued search for simpler and more valid dietary quality indicators among low-income nations.

To explore if and how female adolescents engage in shared eating and joint food choices with best friends within the context of living in urban Soweto, South Africa.

A qualitative, exploratory, multiple case study was conducted using semi-structured duo interviews of best friend pairs to ascertain their eating patterns, friendship and social interactions around dietary habits.

Participants were recruited from three high schools in the urban township of Soweto, South Africa.

Fifty-eight female adolescents (twenty-nine friend pairs) still in high school (mean age of 18 years) were enrolled.

Although overweight rates were high, no association between friends was found; neither did friends share dieting behaviours. Both at school and during visits to the shopping mall, foods were commonly shared and money pooled together by friends to make joint purchases. Some friends carefully planned expenditures together. Foods often bought at school were mostly unhealthy. Availability, price and quality were reported to affect choice of foods purchased at school. Preference shaped joint choices within the shopping mall environment.

Food sharing practices should be investigated in other settings so as to identify specific behaviours and contexts for targeted and tailored obesity prevention interventions. School-based interventions focusing on price and portion size should be considered. In the Sowetan context, larger portions of healthy food may improve dietary intake of fruit and vegetables where friends are likely to share portions.

The objective of the present study was to test the effectiveness of financial incentives and traffic-light labels to reduce purchases of sugar-sweetened beverages in a community supermarket.

In this randomized controlled trial, after a 2-month baseline period (February–March 2014), in-store traffic-light labels were posted to indicate healthy (green), less healthy (yellow) or unhealthy (red) beverages. During the subsequent five months (April–August 2014), participants in the intervention arm were eligible to earn a $US 25 in-store gift card each month they refrained from purchasing red-labelled beverages.

Urban supermarket in Chelsea, MA, USA, a low-income Latino community.

Participants were customers of this supermarket who had at least one child living at home. A total of 148 customers (n 77 in the intervention group and n 71 in the control group) were included in the final analyses.

Outcomes were monthly in-store purchases tracked using a store loyalty card and self-reported consumption of red-labelled beverages. Compared with control participants, the proportion of intervention participants who purchased any red-labelled beverages decreased by 9 % more per month (P=0·002). More intervention than control participants reduced their consumption of red-labelled beverages (−23 % v. −2 % for consuming ≥1 red beverage/week, P=0·01).

Overall, financial incentives paired with in-store traffic-light labels modestly reduced purchase and consumption of sugar-sweetened beverages by customers of a community supermarket.

To assess the effect of the incorporation of amylase in maize-based flours prepared as gruels on the energy intake and growth of Congolese infants.

A randomised controlled trial. At 18 weeks of age, infants were randomised into either an intervention group, where they were provided with a maize/soya-based flour that contained amylase, or a control group, where they were provided with a similar flour that did not contain amylase.

Urban borough of Poto-Poto in Brazzaville, The Congo.

Eighty infants (40 in each group) were randomised into intervention and control groups. Three infants in the intervention group and two controls subsequently dropped out.

At 24 weeks, the addition of amylase resulted in a significant increase in energy intake (in kJ kg-1 day-1) from gruels (P=0.02) without affecting breast milk consumption. In contrast, total energy intake (in kJ kg-1 day-1) did not differ significantly between groups (P=0.08). After adjustment for morbidity and previous growth, infants in the intervention group showed better growth in length during the trial (+0.22 cm month-1; P=0.04), especially between 24 and 31 weeks of age (+0.51 cm month-1; P>0.01). There were no differences in weight velocity between groups.

The findings of this study suggest that the consumption of amylase-treated gruels allows an increase in energy intake from these gruels without affecting breast milk consumption but has no impact on total daily energy intake. However, if started after 6 months, it could be effective in preventing faltering of infant linear growth.

A 5-year nationwide mass media campaign aimed at prevention of overweight was organised from 2002 onwards. The present study evaluates the first campaign, which was aimed primarily at increasing awareness of weight gain.

Data were collected by telephone interview in four independent cross-sectional surveys among non-obese Dutch adults aged 25–35 years (total n = 1949) for statistical analyses. Awareness of personal body-weight status, overweight-related risk perceptions, attitudes towards weight-gain prevention, motivation to prevent weight gain and self-reported body mass index (BMI) were measured in each survey. Campaign exposure was assessed in the post-intervention surveys. To identify intervention effects over time multiple linear and logistic regression analyses were used, adjusted for secular time effects and age.

After the campaign about 65% of the respondents knew about the campaign. The campaign was associated with more positive attitudes towards the prevention of weight gain (β = 0.16; P ≤ 0.01) and higher self-reported BMI (β = 0.14; P ≤ 0.01).

The results suggest that the first campaign reached a large proportion of the population and initiated some positive change in attitudes, but did not achieve significant improvements in other determinants of weight-gain prevention among non-obese young adults.

To (i) determine differences in the availability of variety of fruits and vegetables (F&V) at home by food security status; and (ii) examine the inter-associations between food security status, availability of variety of F&V at home and frequency of F&V intake, among low-income pregnant women.

Participants were interviewed to collect food security status, home availability of variety of F&V and frequency of F&V intake. Bivariate analyses, multivariate regression and exploratory mediation analyses were conducted using IBM SPSS Statistics version 23.0 and the PROCESS macro.

Low-income pregnant women (n 198) were interviewed if they were ≥18 years of age, in the second trimester of pregnancy, and spoke English or Spanish.

Low/very low food security was found among 43 % of participants. Compared with fully food-secure participants, very low food-secure participants reported a lower variety of fruits (P=0·028) and vegetables (P=0·058) available at home. Mediation analyses indicated that through home availability of variety of fresh F&V, food security status was associated with the daily intake of F&V (indirect effect (95 % CI): fresh fruits, −0·039 (−0·074, −0·013); fresh vegetables, −0·048 (−0·083, −0·023)). As food security worsened, the available variety of fresh F&V decreased, which was associated with lower intake.

The study highlights the interlink between food security, home food environment and diet quality, and the importance of nutrition education intervention to promote a healthy home food environment and improved pregnancy outcomes among low-income women.

Maximising synergies and minimising conflicts (i.e. building policy coherence) between trade and nutrition policy is an important objective. One understudied driver of policy coherence is the alignment in the frames, discourses and values of actors involved in the respective sectors. In the present analysis, we aim to understand how such actors interpret (i.e. ‘frame’) nutrition and the implications for building trade–nutrition policy coherence.

We adopted a qualitative single case study design, drawing on key informant interviews with those involved in trade policy.

We focused on the Australian trade policy sub-system, which has historically emphasised achieving market growth and export opportunities for Australian food producers.

Nineteen key informants involved in trade policy spanning the government, civil society, business and academic sectors.

Nutrition had low ‘salience’ in Australian trade policy for several reasons. First, it was not a domestic political priority in Australia nor among its trading partners; few advocacy groups were advocating for nutrition in trade policy. Second, a ‘productivist’ policy paradigm in the food and trade policy sectors strongly emphasised market growth, export opportunities and deregulation over nutrition and other social objectives. Third, few opportunities existed for health advocates to influence trade policy, largely because of limited consultation processes. Fourth, the complexity of nutrition and its inter-linkages with trade presented difficulties for developing a ‘broader discourse’ for engaging the public and political leaders on the topic.

Overcoming these ‘ideational challenges’ is likely to be important to building greater coherence between trade and nutrition policy going forward.

Current indices of diet quality generally include intakes of specific foods or nutrients. We sought to develop an index that discriminates healthy and unhealthy eating choices for use in large surveys as a short questionnaire and as a measure in existing studies with adequate dietary data.

The Eating Choices Index (ECI) score included four components: (i) consumption of breakfast, (ii) consumption of two portions of fruit per day, (iii) type of milk consumed and (iv) type of bread consumed, each providing a score from 1 to 5. In analysis of 5 d food records, the ECI score was examined in relation to macronutrients, fibre, vitamin C, Fe, Ca and folate using Pearson correlations. Variation with sex, BMI, socio-economic status, marital status, smoking status and physical activity were also investigated.

Medical Research Council National Survey of Health and Development.

Individuals (n 2256) aged 43 years.

The ECI score (mean 12·3 (sd 3·5)) was significantly positively associated with protein, carbohydrate, fibre, vitamin C, Fe, Ca and folate (r = 0·2–0·5; P < 0·001) and significantly negatively associated with fat intake (r = –0·2; P < 0·001); ECI scores were not correlated with total energy intake. Individuals with a lower ECI score were more likely to be men (P < 0·001), overweight or obese (P < 0·001), have lower socio-economic status (P < 0·001), smoke more (P < 0·001) and be less physically active (P < 0·001).

ECI scores correlated with nutrient profiles consistent with a healthy diet. It provides a simple method to rank diet healthiness in large observational studies.

We evaluated the association of nutrient intake with Fe deficiency with regard to lifestyle factors and health condition in young Japanese women. Uniquely among developed countries, dietary habits render Japanese populations vulnerable to Fe deficiency, owing to their relatively low intake of Fe and high intake of Fe absorption inhibitors, such as green tea and soyabeans.

A cross-sectional study.

The subjects were 1019 female Japanese dietetic students aged 18–25 years. Dietary habits during the preceding month were assessed using a previously validated, self-administered, diet history questionnaire. Blood analysis was performed to assess body Fe status. Subjects were categorized with Fe deficiency when their serum ferritin levels were <12 ng/ml. Twenty-nine dietary variables, i.e. intakes of energy, sixteen nutrients including Fe and twelve food groups, were analysed using multivariate logistic regression models adjusted for possible confounders.

Of the subjects, 24·5 % were categorized with Fe deficiency. However, no dietary factors assessed were significantly associated with Fe deficiency. The risk of Fe deficiency was significantly lower in women with infrequent or no menstrual cycles than in those with regular cycles (OR = 0·58; 95 % CI 0·34, 1·00) and significantly higher in women with heavy menstrual flow than in women with average flow, albeit that these were self-reported (OR = 1·83; 95 % CI 1·35, 2·48).

These results suggest that dietary habits, including Fe intake, do not significantly correlate with Fe deficiency among young Japanese women.

This systematic review aimed to summarise the level of quality and accuracy of nutrition-related information on websites and social media and determine if quality and accuracy varied between websites and social media or publishers of information.

This systematic review was registered with PROSPERO (CRD42021224277). CINAHL, MEDLINE, Embase, Global Health and Academic Search Complete were systematically searched on 15 January 2021 to identify content analysis studies, published in English after 1989, that evaluated the quality and/or accuracy of nutrition-related information published on websites or social media. A coding framework was used to classify studies’ findings about information quality and/or accuracy as poor, good, moderate or varied. The Academy of Nutrition and Dietetics Quality Criteria Checklist was used to assess the risk of bias.

N/A.

N/A.

From 10 482 articles retrieved, sixty-four were included. Most studies evaluated information from websites (n 53, 82·8 %). Similar numbers of studies assessed quality (n 41, 64·1 %) and accuracy (n 47, 73·4 %). Almost half of the studies reported that quality (n 20, 48·8 %) or accuracy (n 23, 48·9 %) was low. Quality and accuracy of information were similar on social media and websites, however, varied between information publishers. High risk of bias in sample selection and quality or accuracy evaluations was a common limitation.

Online nutrition-related information is often inaccurate and of low quality. Consumers seeking information online are at risk of being misinformed. More action is needed to improve the public’s eHealth and media literacy and the reliability of online nutrition-related information.

The current study aimed to examine the impact of sociodemographic and health-service factors on breast-feeding in sub-Saharan African (SSA) countries with high diarrhoea mortality.

The study used the most recent and pooled Demographic and Health Survey data sets collected in nine SSA countries with high diarrhoea mortality. Multivariate logistic regression models that adjusted for cluster and sampling weights were used to investigate the association between sociodemographic and health-service factors and breast-feeding in SSA countries.

Sub-Saharan Africa with high diarrhoea mortality.

Children (n 50 975) under 24 months old (Burkina Faso (2010, N 5710); Demographic Republic of Congo (2013, N 6797); Ethiopia (2013, N 4193); Kenya (2014, N 7024); Mali (2013, N 3802); Niger (2013, N 4930); Nigeria (2013, N 11 712); Tanzania (2015, N 3894); and Uganda (2010, N 2913)).

Overall prevalence of exclusive breast-feeding (EBF) and early initiation of breast-feeding (EIBF) was 35 and 44 %, respectively. Uganda, Ethiopia and Tanzania had higher EBF prevalence compared with Nigeria and Niger. Prevalence of EIBF was highest in Mali and lowest in Kenya. Higher educational attainment and frequent health-service visits of mothers (i.e. antenatal care, postnatal care and delivery at a health facility) were associated with EBF and EIBF.

Breast-feeding practices in SSA countries with high diarrhoea mortality varied across geographical regions. To improve breast-feeding behaviours among mothers in SSA countries with high diarrhoea mortality, breast-feeding initiatives and policies should be context-specific, measurable and culturally appropriate, and should focus on all women, particularly mothers from low socio-economic groups with limited health-service access.

To compare the dietary habits of Japanese women in Japan with those of Japanese and Caucasian women living in Hawaii.

Data from two previous cross-sectional studies conducted within two years in Hawaii and Gifu, Japan were pooled and analysed. Dietary intakes were assessed with validated food-frequency questionnaires and urine samples were collected for isoflavone measurement.

Participants were recruited through mammography clinics in both locations.

In Hawaii, 164 Caucasian and 146 Japanese women; in Japan, 206 women.

Dietary habits differed considerably by ethnicity and location. In comparison to the Caucasian diet, the diet in Japan was relatively low in fat and high in carbohydrates and protein, whereas the Japanese women in Hawaii reported intermediate intakes. Japanese women in Gifu consumed a diet that was relatively high in fish, soy, eggs and vegetables, and low in fruits, dairy products and meat. In contrast, the Caucasian women consumed the most dairy products and fruits and the Japanese women in Hawaii reported the highest grain and meat intakes.

The diet of Japanese women in Hawaii appeared to be a combination of foods eaten in Japan and the dietary habits of Caucasian women in Hawaii, but eating habits in Japan are also different from traditional nutritional patterns. This study illustrates several problems related to dietary comparisons across populations and provides information for future investigations on chronic disease risk.

The purpose of this evaluation study was to identify strengths and opportunities for improvement in programme functioning and common aspects of patients’ experiences at a hospital-based food pantry.

Semi-structured, in-depth interviews with patients and a cross-sectional survey for providers were used. Interview transcripts were coded using both inductive and deductive approaches and assessed for inter-rater reliability. Descriptive statistics were produced from quantitative data.

An academic urban safety-net hospital in the Northeastern US offering inpatient and outpatient services.

Thirty patients and 89 providers.

Patients expressed feeling comfortable, trusting the food, high satisfaction with food quality, convenience, and lack of stigma at the hospital-based pantry. Patients mentioned the pantry helped them eat more fruits and vegetables, but expressed concerns about the healthfulness of other foods distributed. Providers believed they should discuss food insecurity (FI) with patients (99 %) and that the pantry improves the health of patients (97 %), but faced barriers to consistently screening for FI and referring patients to the pantry, such as insufficient training on FI (53 %) and time constraints (35 %).

Findings suggest hospital-based food pantries may have several advantages. Hospitals with onsite food pantries must work to eliminate barriers to FI screening and pantry referral. To optimize their impact, such pantries should develop nutritional guidelines for food donations and connect patients with nutrition education resources. Future research should examine health outcomes for patients using hospital-based food pantries.

To describe trends of childhood stunting among under-5s in Uganda and to assess the impact of maternal education, wealth and residence on stunting.

Serial and pooled cross-sectional analyses of data from Uganda Demographic and Health Surveys (UDHS) of 1995, 2001, 2006 and 2011. Prevalence of stunting and mean height-for-age Z-score were computed by maternal education, wealth index, region and other sociodemographic characteristics. Multivariable logistic and linear regression models were fitted to survey-specific and pooled data to estimate independent associations between covariates and stunting or Z-score. Sampling weights were applied in all analyses.

Uganda.

Children aged <5 years.

Weighted sample size was 14 747 children. Stunting prevalence decreased from 44·8% in 1995 to 33·2% in 2011. UDHS reported stunting as 38% in 1995, underestimating the decline because of transitioning from National Center for Health Statistics/Centers for Disease Control and Prevention standards to WHO standards. Nevertheless, one in three Ugandan children was still stunted by 2011. South Western, Mid Western, Kampala and East Central regions had highest odds of stunting. Being born in a poor or middle-income household, of a teen mother, without secondary education were associated with stunting. Other persistent stunting predictors included small birth size, male gender and age 2–3 years.

Sustained decrease in stunting suggests that child nutrition interventions have been successful; however, current prevalence does not meet Millennium Development Goals. Stunting remains a public health concern and must be addressed. Customizing established measures such as female education and wealth creation while targeting the most vulnerable groups may further reduce childhood stunting.

To verify the association between perceived social support and household food insecurity (HFI).

A cross-sectional survey.

A population-based study with a representative sample of households from a metropolitan area of Rio de Janeiro, Brazil, conducted in 2010. HFI was estimated with the Brazilian Food Insecurity Scale (EBIA). Social support was assessed using the adapted and validated Brazilian version of the Medical Outcomes Study Social Support Survey. Multinomial logistic regression was used to evaluate the association between social support and HFI, adjusting for potential confounders.

Adults (n 1022) aged 19–60 years old (27 % men, 73 % women) who were responsible for feeding the household.

Individuals with high scores of social support were less likely to experience moderate HFI (OR=0·96; 95 % CI 0·94, 0·99) and severe HFI (OR=0·96; 95 % CI 0·94, 0·98).

These findings indicate that social support may contribute to reducing HFI in populations vulnerable to poverty. Strategies to increase social relationships should be encouraged in this group to enhance their perceived social support.

To identify the factors associated with food insecurity among Quilombolas communities in Brazil.

An analysis of secondary data assessed in the 2011 Quilombolas Census was performed. The Brazilian Food Insecurity Measurement Scale (Escala Brasileira de Insegurança Alimentar, EBIA) was used to assess household food security status. Sociodemographic conditions and access to social programmes and benefits were also evaluated.

National survey census from recognized Quilombolas Brazilian territories.

Quilombolas households (n 8846).

About half (47·8 %) of the Quilombolas lived in severely food-insecure households, with the North and Northeast regions facing the most critical situation. Households located in North Brazil, whose head of the family had less than 4 years of education, with a monthly per capita income below $US 44, without adequate sanitation and without adequate water supply had the greatest chance of experiencing moderate or severe food insecurity. Households that had access to a water supply programme for dry regions (Programa Cisternas) and an agricultural harvest subsidy programme (Programa Garantia Safra) had less chance of experiencing moderate and severe food insecurity. Households that did not have access to health care (Programa Saúde da Família) had greater chance of suffering from moderate or severe food insecurity.

Interventions are urgently needed to strengthen and promote public policies aimed to improve living conditions and food security in Quilombolas communities.

To evaluate the prevalence of vitamin D deficiency and predictors for low vitamin D status in Korean adolescents living between latitudes 33° and 39°N.

A descriptive cross-sectional study.

Korea National Health and Nutrition Examination Survey (KNHANES) 2008–2009.

A total of 1510 healthy adolescents aged 12–18 years (806 male, mean age 14·7 years) participated. Possible predictors for low vitamin D status (log-transformed 25-hydroxyvitamin D (25(OH)D) concentrations) were evaluated.

The prevalence of vitamin D deficiency (25(OH)D<20 ng/ml) was 89·1 % in spring, 53·7 % in summer, 63·9 % in autumn and 90·5 % in winter. Winter season, older age, higher education level reached, being female, being obese, a lack of vitamin D supplementation, lower milk consumption (0–<200 ml/d) and a lack of physical activity were unadjusted predictors (all P < 0·05). Multiple linear regression analysis showed that winter season (P < 0·001), higher education level (P < 0·001) and a lack of vitamin D supplementation (P = 0·012) were independent predictors for low vitamin D status. The modifying effect of season on the association between vitamin D supplement use and vitamin D status was significant (P < 0·001).

Vitamin D deficiency was highly prevalent in Korean adolescents, especially those in higher school grades. Vitamin D supplementation may contribute to maintain a better vitamin D status with lower seasonal variation. Further studies are required to determine optimal vitamin D intakes to maintain sufficient vitamin D status for Korean adolescents.