The World Health Organisation describes micronutrient deficiencies, or hidden hunger, as a form of malnutrition that occurs due to low intake and/or absorption of minerals and vitamins, putting human development and health at risk. In many cases, emphasis, effort, and even policy, revolves around the prevention of deficiency of one particular micronutrient in isolation. This is understandable as that micronutrient may be among a group of nutrients of public health concern. Vitamin D is a good exemplar. This review will highlight how the actions taken to tackle low vitamin D status have been highly dependent on the generation of new data and/or new approaches to analysis of existing data, to help develop the evidence-base, inform advice/guidelines, and in some cases, translate into policy. Beyond focus on individual micronutrients, there has also been increasing international attention around hidden hunger, or deficiencies of a range of micronutrients, which can exist unaccompanied by obvious clinical signs but can adversely affect human development and health. A widely quoted estimate of the global prevalence of hidden hunger is a staggering two billion people, but this is now over 30 years old. This review will outline how strategic data sharing and generation is seeking to address this key knowledge gap in relation to the true prevalence of hidden hunger in Europe, a key starting point towards defining sustainable and cost-effective, food-based strategies for its prevention. The availability of data on prevalence and food-based strategies can help inform public policy to eradicate micronutrient deficiency in Europe.

To analyse the association of socio-demographic and health factors with vitamin D insufficiency and 25-hydroxyvitamin D (25(OH)D) concentration in Brazilian children aged 6–59 months. Data from 8145 children from the Brazilian National Survey on Child Nutrition (ENANI-2019) were analysed. The serum concentration of 25(OHD)D was measured using a chemiluminescent immunoassay. The prevalence of vitamin D insufficiency (25(OH)D < 50 nmol/l) and 95 % CI was calculated. Logistic and linear regression models were used to identify the variables associated with vitamin D insufficiency and serum 25(OH)D concentrations, respectively. The mean 25(OH)D concentration was 98·6 ± 36·0 nmol/l, and 4·3 % of the children presented vitamin D insufficiency. Children aged 6–23 months (OR = 2·23; 95 % CI 1·52, 3·26); belonging to Southeast (OR = 5·55; 95 % CI 2·34, 13·17) and South (OR = 4·57; 95 % CI 1·77, 11·84) regions; the second tertile of the National Wealth Score (OR = 2·14; 95 % CI 1·16, 3·91) and winter (OR = 5·82; 95 % CI 2·67, 12·71) and spring (OR = 4·84; 95 % CI 2·17, 10·80) seasons of blood collection were associated with a higher chance of vitamin D insufficiency. Female sex (β = −5·66, 95 % CI − 7·81, −3·51), urban location (β = −14·19, 95 % CI −21·0, −7·22) and no vitamin D supplement use (β = −6·01, 95 % CI −9·64, −2·39) were inversely associated with serum 25(OH)D concentration. The age of children and the Brazilian geographical region of household location were the main predictors of vitamin D insufficiency. In Brazil, vitamin D insufficiency among children aged 6–59 months is low and is not a relevant public health problem.

Although micronutrient deficiencies affect 2 billion people worldwide, no index focuses on measuring the risk of overt nutrient deficiency. We aimed to develop an index that could capture the nutrient dimension of nutritional security, a nutrient security index (named SecDiet), and evaluate its apparent validity. The SecDiet (range: 0–1) is based on the square-weighted average of the probabilities that the intake of twelve critical nutrients exceeds the threshold value associated with a risk of overt deficiency. Using adult populations from a French representative survey (INCA3, n 1774) and a large cohort (NutriNet-Santé, n 104 382), the content and construct validity of the SecDiet was evaluated by estimating associations of the SecDiet with its components and with relevant socio-demographic characteristics. The SecDiet was high in the overall population (0·93 (SD 0·09) in INCA3) and markedly skewed towards 1 (i.e. lower risk of insufficient intake). It correlated positively with its twelve components (r 0·17–0·78, all P < 0·001). The SecDiet was associated with monthly income (P = 0·002), perception of financial situation, professional situation, food insufficiency and security statuses (all P < 0·001) in the INCA3 population and with monthly income, professional situation and level of education (all P < 0·001) in the NutriNet-Santé population. Unlike a broader nutrient-based quality index taken as comparison, the SecDiet mean decreased and the tail of its distribution notably extended downwards in at-risk sub-populations, thus revealing its specific sensitivity. The SecDiet could be used to screen sub-groups or study the determinants of nutrient insecurity in large population surveys.

Psychosis increases the risk of CVD, obesity and type 2 diabetes and reduces life expectancy. There are limited data comparing the dietary habits of community-dwelling first-episode psychosis sufferers – with autonomy over diet – and the general population. The data represent the retrospective evaluation of nutritional data collected between 2007 and 2013 from 143 individuals from the UK population receiving treatment for first-episode psychosis. Differences in mean nutrient intakes between the study cohort and the national sample were tested for statistical significance using independent t tests, incorporating Satterthwaite's correction where required. Mean total energy intake was lower for males (P = 0·049) and higher for females (P = 0·016) in the cohort than in the corresponding subgroups of the national sample. Females in the study cohort consumed 12·9 (95 % CI 4·3, 21·5) g more total fat per d, whilst males consumed 7·7 (95 % CI 0·5, 14·9) g less protein per d than the national sample. Males in the study also showed significantly lower mean intakes than nationally of folate, Fe, Se, vitamin D and Zn, but not vitamin C. The proportion of individuals not meeting the lower reference nutrient intakes, particularly for Se (males 54·0 % and females 57·1 %) and for Fe amongst females (29·6 %), is cause for concern regarding potentially severe deficiencies. Further exploration of dietary habits within first-episode psychosis is warranted to assess whether individuals make beneficial dietary changes for their physical and mental health and wellbeing following dietary change intervention. It would also be pertinent to assess any correlation between diet and mental health symptomology.

A population-based cross-sectional study was carried out in the northern neighbourhoods of Ouagadougou (Burkina Faso), to examine the relationship of nutritional deficiencies and cardiometabolic risk factors (CMRF) with lifestyle in adults. We randomly selected 330 households stratified by income tertile. In each income stratum, 110 individuals aged 25–60 years and having lived in Ouagadougou for at least 6 months were randomly selected. We performed anthropometric, dietary intake and physical activity measurements, and blood sample collection. Cluster analysis of dietary intake identified two dietary patterns: ‘urban’ (29 % of subjects) and ‘traditional’ (71 %). The ‘urban’ cluster exhibited a higher intake of fat and sugar, whereas a higher intake of plant protein, complex carbohydrate and fibre was observed in the ‘traditional’ pattern. Female sex, low income and lack of education were associated with the ‘traditional’ cluster, as well as Fe and vitamin A deficiency. CMRF prevalence (abdominal obesity, hypertension, hyperglycaemia, dyslipidaemia) was similar in both clusters. Subjects in the ‘traditional’ cluster spent more time in physical activity and had less sedentary time than those in the ‘urban’ cluster. ‘Traditional’ dietary pattern, low income, female sex and sedentary time were significant contributing factors to the double burden of malnutrition. The rapid nutrition transition is reflected in this co-occurrence of CMRF and nutritional deficiencies. This stresses the need for prevention strategies addressing both ends of the nutrition spectrum.

Indonesia is currently facing the double burden of malnutrition. While undernutrition is still a major public health problem, the prevalence of overnutrition is increasing. The objective of the South East Asian Nutrition Survey (SEANUTS) was to provide up-to-date data on nutritional status, food consumption and biochemical parameters related to nutrition for children aged 0·5–12 years. The SEANUTS study in Indonesia was conducted in a nationwide representative sample of 7·211 children using multistage cluster sampling based on probability proportional to size, stratified for geographical location, in forty-eight out of 440 districts/cities. The results show that the growth (weight for age, height for age, weight for height and BMI for age) of Indonesian pre-school- and school-aged children is below the WHO standards. The older the children, the more the deviation from the WHO standard curves. Underweight was more prevalent in rural areas (28·9 v. 19·2 %) and overweight/obesity was observed to be more widespread in urban areas (5·6 v. 3·2 %). The prevalence varied with age groups and sexes. The overall prevalence of stunting was 25·2 and 39·2 % in urban and rural areas, respectively. The prevalence of anaemia was nearly 55 % in children aged 0·5–1·9 years and ranged from 10·6 to 15·5 % in children aged 2–12 years. Fe deficiency was observed in 4·1–8·8 % of the children. The percentage of children with dietary intakes of energy, protein, and vitamins A and C below the Indonesian RDA was high and differed across urban and rural areas and age groups.

In the present study, we investigated nutritional status and health-related factors in a multistage cluster sample of 3119 Thai urban and rural children aged 0·5–12·9 years. In a subsample, blood samples were collected for the measurement of Hb, transferrin receptor, vitamin A and vitamin D concentrations. The prevalence of stunting and underweight was higher in rural children than in urban children, whereas the wasting rate was similar in both rural and urban areas. Among children aged 3·0–5·9 years, the prevalence of overweight was significantly higher in urban areas than in rural areas and so was the obesity rate in children aged 6·0–12·9 years. Protein intakes of all age groups were relatively high in both the areas. Intakes of Ca, Fe, Zn and vitamin C were significantly higher in urban areas than in rural areas. The prevalence of anaemia in rural areas was twice as high as that in urban areas, particularly in infants and young children. However, the prevalence of Fe-deficiency anaemia was similar in both urban and rural areas. While the prevalence of vitamin A deficiency (by serum retinol cut-off < 0·7 μmol/l) seemed to be very low, vitamin A insufficiency (by serum retinol cut-off < 1·05 μmol/l) was more prevalent (29·4–31·7 %) in both the areas. The prevalence of vitamin D insufficiency ranged between 27·7 and 45·6 % among the children. The present study indicates that the double burden of malnutrition is still a major public health problem in Thailand. Further studies need to explore the associated risk factors for these nutrient deficiencies. Effective strategies and actions are needed to tackle the nutritional problems in Thai children.

Increasing evidence suggests that high-sensitivity C-reactive protein (hs-CRP) is associated with cardiometabolic risk factors (CMRF) while being also related to micronutrient deficiencies. As part of a project on the double burden of under- and overnutrition in sub-Saharan Africa, we assessed the relationship between hs-CRP and both CMRF and micronutrient deficiencies in a population-based cross-sectional study carried out in the Northern district of Ouagadougou, the capital city of Burkina Faso. We randomly selected 330 households stratified by income tertile. In each income stratum, 110 individuals aged 25–60 years and having lived in Ouagadougou for at least 6 months were randomly selected, and underwent anthropometric measurements and blood sample collection. The prevalence of high hs-CRP was 39·4 %, with no sex difference. Vitamin A-deficient subjects (12·7 %) exhibited significant risk of elevated hs-CRP (OR 2·5; P= 0·015). Serum ferritin was positively correlated with log hs-CRP (r 0·194; P= 0·002). The risk of elevated hs-CRP was significant in subjects with BMI ≥ 25 kg/m2 (OR 6·9; 95 % CI 3·6, 13·3), abdominal obesity (OR 4·6; 95 % CI 2·2, 7·3) and high body fat (OR 10·2; 95 % CI 5·1, 20·3) (P< 0·001, respectively). Independent predictors of hs-CRP in linear regression models were waist circumference (β = 0·306; P= 0·018) and serum TAG (β = 0·158; P= 0·027). In this sub-Saharan population, hs-CRP was consistently associated with adiposity. Assuming that plasma hs-CRP reflects future risk of cardiovascular events, intervention which reduces CRP, or chronic and acute nutrition conditions associated with it, could be effective in preventing their occurrence particularly in sub-Saharan Africa.

Almost anything that is swallowed in pill or potion form that is not a licensed medicine is, by default, legally classified as a dietary supplement. The present paper is an overview of supplement use and is intended to provide a logical framework for their discussion. Five major supplement categories are identified: essential micronutrients; other metabolites that have vitamin-like roles; natural oils; natural plant or animal extracts; antioxidants, which span the other categories. Supplement usage is also classified into broad categories. Examples of each supplement category and usage are briefly discussed. Some potential hazards of supplement use are also outlined; many substances in supplements are either not found in normal UK diets or consumed in much greater amounts than would be found in food. Many supplements are used for pharmaceutical purposes and sold as supplements to avoid the expense of acquiring a medicinal licence and to avoid the stricter quality-control regulations that apply to medicines. The use of supplements to ensure nutritional adequacy and as possible conditionally-essential nutrients is briefly discussed, as is their essentially pharmaceutical use for the prevention and alleviation of disease. There is critical discussion of whether the use of antioxidant supplements is justified or even if it is reasonable to promote a particular food on the basis of antioxidant content alone. Much of the research on supplements is reductionist, commercially sponsored or has other weaknesses; so, despite decades of use and research there is still uncertainty about their efficacy in many cases.

Major advances have occurred in food production during the last 30 years as a result of the adoption of ‘green revolution’ technology. The price of rice and wheat is 40 % lower than it was in the 1950s. This lower price has helped the poorer sections of society, who spend 50–60 % of their income on food. The proportion of the population in the developing world that is malnourished fell from 46·5 % in the early 1960s to 31 % in 1995. However, there are still 1·3 billion of the population who go to bed hungry every day. Deficiencies of micronutrients such as Fe, Zn and vitamin A affect millions of the population in the developing world. The world population is increasing at the rate of 1·4 %, or an increase of eighty million per year. It is estimated that we will have to produce 50 % more food grains by 2025. Various strategies for meeting this challenge exist, including the development of cereal varieties with a higher yield potential and yield stability, and farmer-friendly public policies. In order to tackle hidden hunger, efforts are underway to develop crop varieties with higher concentrations of Fe and Zn. Recently, a breakthrough has occurred in the introduction of the genes for the pathway leading to the biosynthesis of β-carotene, a precursor of vitamin A, in rice. Various conventional approaches and modern tools of biotechnology are being employed in the development of crop varieties with higher yields and higher levels of micronutrients.

Since the last century, fortified and enriched foods are products whose original composition has been modified–through addition of essential nutrients–to satisfy specific population needs. For the fortification of foods to have a positive impact on nutritional status, the micronutrients added must be well absorbed and utilized by the organism (bioavailability). Diverse factors affect bioavailability, such as the nutritional status of individuals, the presence in the diet of substances which facilitate or inhibit its absorption, interactions among micronutrients, illnesses, and chemical characteristics of the compound used for fortification. In countries such as Chile, Venezuela and Mexico, important effects have been demonstrated in reducing iron deficiency anaemia in children under 5 years of age. In less than a decade, the salt iodization programme has also proven its effectiveness. Other programmes have fortified foods with Zn, vitamin A and folic acid, which are deficient in infants and children of many populations. In summary, food fortification is a low-cost, relatively simple strategy that may reach a wide range of people, and contribute to reducing the high prevalence of micronutrient deficiencies affecting children, especially in poor countries. The costs due to losses of human capital and their repercussions on health and future development are very high. Building links among academic researchers, politicians, food manufacturers and consumers is essential in order for food fortification to be efficacious and effective, and therefore should be considered as part of an integral strategy to combat micronutrient deficiencies.