Role of micronutrient elements in the metabolism of higher plants. I. Changes in oxidative enzyme constitution of tomato leaves deficient in micronutrient elements.
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OBJECTIVE: To examine associations between breakfast cereal consumption and the dietary habits, nutrient intakes and nutritional status of young people, considering both nutrient adequacy and safety issues (fortification). METHODS: Using archived data from 1688 children in the (British) National Diet and Nutrition Survey of Young People aged 4 to 18 years, nutrient intakes and status were compared across thirds of breakfast cereal consumption (T1 to T3), adjusted for age and energy intake. Cereals provided on average 2%, 6% and 12% of energy in T1, T2 and T3, respectively, for boys; 1%, 4% and 10%, respectively, for girls. RESULTS: Intakes of iron, B vitamins and vitamin D were around 20-60% higher in T3 compared with T1, with significant linear relationships observed for iron, thiamin, riboflavin and folate (T1<T2<T3). After excluding low energy reporters and the unwell, 14% of girls had iron intakes below the Lower Reference Nutrient Intake and this varied fivefold between T1 and T3 (27%, 12% and 5%; P=0.0001). High consumers of breakfast cereals (T3) had better folate, vitamin B12 and riboflavin status and lower total and low-density lipoprotein cholesterol. There was also an association with thiamin and vitamin B6 status in girls. However, iron status (haemoglobin, ferritin and transferrin saturation) was not significantly different between groups, possibly due to lower meat intakes in T3. Total iron intakes were within tolerable levels (maximum of 32 mg day(-1) in one girl taking supplements). CONCLUSIONS: The nutritional benefits of breakfast cereals are demonstrated in status measurements as well as in nutrient intakes in this study. Concerns about excessive iron intakes from fortification appear unjustified.
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Serum antioxidant vitamins A (retinol) and E (alpha-tocopherol), beta-carotene, zinc and selenium for 418 children with newly diagnosed malignancy were compared with those of 632 cancer-free controls. Incident cancer cases and controls were 1-16 years old and recruited in 1986-1989. Age- and sex-adjusted serum concentrations of retinol, beta-carotene and alpha-tocopherol were significantly inversely associated with cancer. In similar models, the odds ratio (OR) comparing the highest with the lowest quintile was 2.06 (95% confidence interval [CI] 1.40-3.02) for retinol, 3.87 (95% CI: 2.54-5.90) for beta-carotene, 2.15 (95% CI: 1.48-3.10) for alpha-tocopherol, 1.29 (95% CI: 0.75-2.23) for selenium, and 1.94 (95% CI: 1.17-2.23) for zinc. The cancer sites that were associated with serum beta-carotene were, in general, leukaemia, lymphoma, central nervous system, bone and renal tumours. Moreover, leukaemia was associated with low mean serum levels of retinol, selenium and zinc. Subjects with lymphoma, bone and renal tumours also had lower mean retinol and alpha-tocopherol levels than controls. Brain tumour patients had low vitamin E levels. Low serum values of antioxidant vitamins were associated with childhood neoplasm occurrence. Some site-specific effect was reported. Low peripheral nutrient levels are not considered as cancer promoters but rather as an impairment of the body's defence mechanism occurring during the cancer-related metabolic and nutritional disturbances and inflammation processes.
BACKGROUND: Multiple-micronutrient deficiencies often coexist in low- to middle-income countries. They are exacerbated in pregnancy due to the increased demands, leading to potentially adverse effects on the mother. Substantive evidence regarding the effectiveness of multiple-micronutrient supplements (MMS) during pregnancy is not available. OBJECTIVES: To evaluate the benefits to mother and infant of multiple-micronutrient supplements in pregnancy and assess the risk of excess supplementation and potential adverse interactions between micronutrients. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 December 2005). SELECTION CRITERIA: All prospective randomised controlled trials evaluating micronutrient supplementation during pregnancy and its effects on the pregnancy outcome. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trial quality and extracted the data. MAIN RESULTS: Nine trials (15,378 women) are included. When compared with supplementation of two or less micronutrients or no supplementation or a placebo, multiple-micronutrient supplementation resulted in a statistically significant decrease in the number of low birthweight babies (relative risk (RR) 0.83; 95% confidence interval (CI) 0.76 to 0.91), small-for-gestational-age babies (RR 0.92; 95% CI 0.86 to 0.99) and in maternal anaemia (RR 0.61; CI 0.52 to 0.71). However, these differences lost statistical significance when multiple-micronutrient supplementation was compared with iron folic acid supplementation alone. No statistically significant differences were shown for the outcomes of preterm births and perinatal mortality in any of the comparisons. A number of prespecified clinically important outcomes could not be assessed due to insufficient or non-available data from the included trials. These include placental abruption, congenital anomalies including neural tube defects, premature rupture of membranes, pre-eclampsia, miscarriage, maternal mortality, neurodevelopmental delay, very preterm births, cost of supplementation, side-effects of supplements, maternal wellbeing or satisfaction and nutritional status of children. AUTHORS' CONCLUSIONS: The evidence provided in this review is insufficient to suggest replacement of iron and folate supplementation with a multiple-micronutrient supplement. A reduction in the number of low birthweight and small-for-gestational-age babies and maternal anaemia has been found with a multiple-micronutrient supplement against supplementation with two or less micronutrients or none or a placebo, but analyses revealed no added benefit of multiple-micronutrient supplements compared with iron folic acid supplementation. These results are limited by the small number of studies available. There is also insufficient evidence to identify adverse effects and to say that excess multiple-micronutrient supplementation during pregnancy is harmful to the mother or the fetus. Further research is needed to find out the beneficial maternal or fetal effects and to assess the risk of excess supplementation and potential adverse interactions between the micronutrients.
UNLABELLED: Deficiencies of micronutrients (zinc, iron, folic acid and iodine) during pregnancy are known causes of Low Birth Weight (LBW). Studies have documented status of one or two micronutrients amongst pregnant women (PW). However, no attempt has been made to concurrently assess the prevalence of multiple micronutrient deficiencies and the factors associated with them amongst PW. OBJECTIVE: The present study was undertaken to assess the prevalence of multiple micronutrient deficiencies amongst PW in a rural area. METHODS: A community based cross sectional survey was conducted in six villages of a rural area of district Faridabad in Haryana state, India during November 2000 and October 2001. All PW aged 18 years or more, with pregnancy duration of more than 28 weeks were enrolled. Data were collected on socio-economic status and other demographic parameters. Serum zinc, copper and magnesium levels were estimated by utilizing the Atomic absorption spectrophotometry (AAS); serum ferritin and folate was estimated by Enzyme Linked Immuno Sorbent Assay (ELISA) method and the Radio-Immuno Assay (RIA) method, respectively and serum thyroid stimulating hormone (TSH) level was estimated by the Abbot AxSYM System. Serum zinc, copper, magnesium, ferritin, and folate levels less than 70.0 microg/dl, 80.0 microg/dl, 1.80 mg/dl, 15 ng/ml, and 3 ng/ml, respectively were considered as indicative of deficiency for respective micronutrients. The TSH levels of 4.670 and more indicated iodine deficiency status. Dietary intake of micronutrients was assessed utilizing 1-day 24-hour dietary recall methodology. Food consumption pattern was assessed utilizing the food frequency questionnaire methodology. RESULTS: Nearly 73.5, 2.7, 43.6, 73.4, 26.3, and 6.4 percent PW were deficient in zinc, copper, magnesium, iron, folic acid and iodine, respectively. The highest concurrent prevalence of two, three, four and five micronutrient deficiency was of zinc and iron (54.9%); zinc, magnesium and iron (25.6%); zinc, magnesium, iron and folic acid (9.3%) and zinc, magnesium, iron, folic acid and iodine (0.8%), respectively. No pregnant woman was found to have concomitant deficiencies of all the six micronutrients. Dietary intake data revealed an inadequate nutrient intake. Over 19% PW were consuming less than 50% of the recommended calories. Similarly, 99, 86.2, 75.4, 23.6, 3.9 percent of the PW were consuming less than 50% of the recommended folic acid, zinc, iron, copper, and magnesium. The consumption of food groups rich in micronutrients (pulses, vegetables, fruits, nuts and oil seeds, animal foods) was infrequent. Univariate and Multivariate logistic regression analysis revealed that low dietary intake of nutrients, low frequency of consumption of food groups rich in micronutrients and increased reproductive cycles with short interpregnancy intervals were important factors leading to micronutrient deficiencies. CONCLUSION: There was a high prevalence of micronutrient deficiencies amongst the PW of the area, possibly due to the poor dietary intake of food and low frequency of consumption of food groups rich in micronutrients. The concurrent prevalence of two, three, four and five micronutrient deficiencies were common.
BACKGROUND: Low body mass index (BMI) and micronutrient deficiencies are associated with increased morbidity and mortality rates in old age. Whether adverse patterns of dietary variety predict both low BMI and low micronutrient intakes in older adults was investigated. METHODS: A cross-sectional analysis of national survey data was conducted in 1174 healthy adult men and women (ages 21 to 90 years) who provided physiologically plausible dietary data in the 1994-1996 Continuing Survey of Food Intakes by Individuals. Measurements included reported energy intake, protein intake (percentage meeting Recommended Dietary Allowance), micronutrient intakes (percentage meeting Estimated Average Requirements for 14 micronutrients), and BMI. RESULTS: Adults who were 61 years or older consumed a greater total variety of foods, chose foods from a wider range of food groups, had a greater variety of micronutrient-dense foods and energy-weak foods, and had a lower variety of micronutrient-weak foods compared with adults ages 21 to 60 years (p < .05 to.001). However, older adults with low BMIs (< 22 kg/m2) consumed a lower variety of energy-dense foods compared with older adults with higher BMIs (p < .05). The variety of energy-dense foods predicted both energy intake and BMI at all ages in multiple regression models controlling for confounding variables (R2 = .124 for energy, R2 = .574 for BMI, p < .001). A higher percentage of older persons had inadequate micronutrient intakes compared with younger persons (p < .05), especially vitamin E, calcium, and magnesium, but consumption of a particularly wide variety of micronutrient-rich foods helped counterbalance these trends (p < .05). Older adults who had a low BMI and consumed a low variety of micronutrient-dense foods were particularly at nutritional risk, with only 65.4% consuming the Recommended Dietary Allowance for protein and none meeting the Estimated Average Requirements for all 14 micronutrients. CONCLUSIONS: In contrast to previous suggestions that older persons consume a monotonous diet, this study showed that adults who were 61 years or older consumed a greater total food variety, and a greater variety of micronutrient-dense and energy-weak foods, compared with adults who were 60 years or younger. Although consumption of a low variety of energy-dense foods may contribute to reduced energy intake and body weight at any age, the variety of micronutrient-dense foods consumed needs to increase in old age to prevent micronutrient deficiencies. These findings suggest that all adults need advice on the changing needs for dietary variety with aging to maintain health, and that older persons with low BMI are particularly vulnerable to dietary shortfalls.
Cigarette smoke is a significant source of oxidative stress, one potential mechanism for its untoward health effects. The antioxidant defense system is partly comprised of antioxidant micronutrients, making it important to understand the relationship between cigarette smoking and circulating concentrations of antioxidant micronutrients. A synthesis of the literature shows that compared with nonsmokers, on average, active smokers have greater than 25% lower circulating concentrations of ascorbic acid, alpha-carotene, beta-carotene, and cryptoxanthin. The differences in blood concentrations of these micronutrients in former smokers is intermediate between never and current smokers, but average circulating concentrations of alpha-carotene, beta-carotene, and cryptoxanthin were 16-22% lower in former smokers compared with never smokers. Differences in dietary habits between smokers and nonsmokers could potentially account for these associations. Dietary micronutrient intake is associated with blood micronutrient concentrations. Furthermore, patterns of micronutrient consumption by smoking status mimic the pattern of associations observed for blood concentrations. For example, when pooled across studies intake of vitamin C was 16% lower in current smokers and 2% lower in former smokers than in never smokers; the corresponding figures for beta-carotene were 17 and 4%, respectively. Despite the strong potential for confounding, the differences observed between current smokers and nonsmokers seem to be due to an acute effect of smoking based on results of studies of smoking and antioxidant micronutrient concentrations that have either adjusted for dietary antioxidant micronutrient intake and other potential confounding factors or documented short term changes in circulating antioxidant micronutrient concentrations in smokers before and after smoking cigarettes. The associations observed with active smoking also appear to hold true for passive smoking, implying that even low-dose exposures to tobacco smoke can result in lowered circulating antioxidant micronutrient concentrations. Smoking was more weakly associated with circulating concentrations of vitamin E and the nonprovitamin A carotenoids lutein/zeaxanthin and lycopene. The combined evidence supports the conclusion that cigarette smoking is independently associated with lowered circulating concentrations of ascorbic acid and provitamin A carotenoids. These associations have implications for the design and interpretation of epidemiologic studies of antioxidant micronutrients in relation to health and disease. To the extent that these micronutrients are associated with health and longevity, this evidence documents yet another deleterious consequence of cigarette smoking on human health.
Whilst clinical deficiency of micronutrients is uncommon in the developed world, a suboptimal intake of certain micronutrients has been linked with an increased risk of chronic diseases such as CVD and cancer. Attention has therefore focused on increasing micronutrient status in order to theoretically reduce chronic disease risk. Increasing micronutrient status can involve a number of approaches: increasing dietary intake of micronutrient-rich foods; food fortification; use of supplements. Observational cohort studies have demonstrated an association between high intakes of micronutrients such as vitamin E, vitamin C, folic acid and beta-carotene, and lower risk of CHD, stroke and cancer at various sites. However, randomised intervention trials of micronutrient supplements have, to date, largely failed to show an improvement in clinical end points. The discordance between data from cohort studies and the results so far available from clinical trials remains to be explained. One reason may be that the complex mixture of micronutrients found, for example, in a diet high in fruit and vegetables may be more effective than large doses of a small number of micronutrients, and therefore that intervention studies that use single micronutrient supplements are unlikely to produce a lowering of disease risk. Studies concentrating on whole foods (e.g. fruit and vegetables) or diet pattern (e.g. Mediterranean diet pattern) may be more effective in demonstrating an effect on clinical end points. The present review will consider the clinical trial evidence for a beneficial effect of micronutrient supplements on health, and review the alternative approaches to the study of dietary intake of micronutrients.
Vitamins and minerals serve essential roles in cellular metabolism, maintenance and growth throughout life. They are also central components of many enzymes and transcription factors. However, the need for optimum amounts of key micronutrients at critical stages during the periovulatory period and subsequent embryonic and fetal life has become the focus of sustained research activity only recently. In addition to folic acid, the minerals zinc, iron and copper and the antioxidant vitamins A and E are of particular importance during pregnancy. Both excesses and deficiencies of these micronutrients can have profound and sometimes persistent effects on many fetal tissues and organs in the absence of clinical signs of deficiency in the mother. The consequences of micronutrient imbalance on the developing conceptus may not be apparent at the time of the nutritional insult, but may be manifest later in development. However, supplementary micronutrients provided later in gestation or during postnatal life cannot completely reverse the detrimental effects of earlier micronutrient imbalance. Importantly, deficiency of a specific micronutrient, such as zinc, during pregnancy can result in a greater incidence of fetal malformation and resorptions than general undernutrition. Given the range of micronutrients that affect development, the number of developmental stages susceptible to inappropriate micronutrient status and the diverse biochemical systems and types of tissue affected, it is challenging to propose a unifying hypothesis that could explain the effects of micronutrient imbalance on programming throughout gestation. Micronutrient imbalance can affect pregnancy outcome through alterations in maternal and conceptus metabolism, as a consequence of their essential role in enzymes and transcription factors and through their involvement in signal transduction pathways that regulate development. Micronutrient-induced disturbances in the balance between the generation of free oxygen radicals and the production of antioxidants that scavenge free radicals may provide an additional mechanistic explanation. The detrimental effects of many micronutrient deficiencies, particularly zinc and copper, can be alleviated by supplementary antioxidants, whereas deficiencies of antioxidant vitamins A and E are likely to reduce defence against free radical damage.
The present literature review examines the following questions: (a) What is the evidence that micronutrient requirements are increased in physically active people? (b) Is there an association between physical activity and micronutrient intake? (c) Are there any significant differences between indices of micronutrient status between physically active and inactive people? The available data suggest that micronutrient requirements are increased in physically active people because of increased losses through sweat, urine and faeces, and an increased need for defence against free radicals. However the evidence is controversial, and it is not possible to make any quantitative estimations. Micronutrient requirements in moderately active people are not likely to be very much above the levels recommended for the general population. The intake of micronutrients increases with increasing energy intake. Therefore, physically highly active people (athletes) have higher micronutrient intakes than untrained subjects. However, moderate physical activity does not necessarily affect daily micronutrient intake. The available indices of micronutrient status do not support the belief that micronutrient status is compromised in highly trained athletes, even without use of dietary supplements. Hence, there are no reasons to believe that the situation would be different in people who are only moderately active. The results suggest that micronutrient status is adequate for health and functional performance in physically active people who follow a normal, mixed Western diet.
In seeking to improve the micronutrient contents of a food supplement used in a major community-based nutrition project in Bangladesh, operations research was conducted to compare the provision of needed micronutrients through additional food sources (fresh or dried fruits or vegetables), a micronutrient multi-mix, and a combination of the two. Micronutrient gaps (the difference between micronutrient requirements and actual micronutrient intake) were estimated for four groups of project beneficiaries, with target intakes defined as requirements for iron, calcium, zinc, vitamin A, vitamin C, riboflavin, niacin, and vitamin B12 recommended by the Food and Agriculture Organization/World Health Organization. Primary focus was placed on iron and vitamin A. Cost and bulk constraint analyses, based on cost of supplement, feasibility of delivery, and serving volume needed to achieve micronutrient targets, were used for comparing the supplement options. In terms of these analyses, the micronutrient multimix proved, by far, to be the most advantageous. Food options, however, are arguably desirable in that they provide dietary benefits additional to that of known micronutrients and may increase demand to boost production of domestic fruits and vegetables for the population as a whole. The study concludes that it is cost-effective to use powdered micronutrient mixes for such specific purposes as enrichment of supplementary food and food fortification, but encourages production and consumption of micronutrient-rich foods through programme messages and activities.
Over three billion people are currently micronutrient (i.e. micronutrient elements and vitamins) malnourished, resulting in egregious societal costs including learning disabilities among children, increased morbidity and mortality rates, lower worker productivity, and high healthcare costs, all factors diminishing human potential, felicity, and national economic development. Nutritional deficiencies (e.g. iron, zinc, vitamin A) account for almost two-thirds of the childhood death worldwide. Most of those afflicted are dependent on staple crops for their sustenance. Importantly, these crops can be enriched (i.e. 'biofortified') with micronutrients using plant breeding and/or transgenic strategies, because micronutrient enrichment traits exist within their genomes that can to used for substantially increasing micronutrient levels in these foods without negatively impacting crop productivity. Furthermore, 'proof of concept' studies have been published using transgenic approaches to biofortify staple crops (e.g. high beta-carotene 'golden rice' grain, high ferritin-Fe rice grain, etc). In addition, micronutrient element enrichment of seeds can increase crop yields when sowed to micronutrient-poor soils, assuring their adoption by farmers. Bioavailability issues must be addressed when employing plant breeding and/or transgenic approaches to reduce micronutrient malnutrition. Enhancing substances (e.g. ascorbic acid, S-containing amino acids, etc) that promote micronutrient bioavailability or decreasing antinutrient substances (e.g. phytate, polyphenolics, etc) that inhibit micronutrient bioavailability, are both options that could be pursued, but the latter approach should be used with caution. The world's agricultural community should adopt plant breeding and other genetic technologies to improve human health, and the world's nutrition and health communities should support these efforts. Sustainable solutions to this enormous global problem of 'hidden hunger' will not come without employing agricultural approaches.
OBJECTIVE: To examine the immunologic, metabolic, and clinical effects of broad spectrum micronutrient supplementation in HIV-infected patients taking highly active antiretroviral therapy (HAART). DESIGN: A prospective, randomized, double-blinded, placebo-controlled trial. METHODS: Forty HIV-infected patients taking a stavudine and/or didanosine-based HAART regimen were prospectively randomized to receive micronutrients or placebo twice daily for 12 weeks. Data were collected at 4-week intervals including immunologic, metabolic, and clinical measurements. The study examined the effect of micronutrient supplementation on immunologic parameters as the primary end point. The secondary end points were metabolic and clinical effects and distal symmetrical polyneuropathy. RESULTS: The mean absolute CD4 count increased by an average of 65 cells in the micronutrient group versus a 6-cell decline in the placebo group at 12 weeks (P = 0.029). The absolute CD4 count increased by an average of 24% in the micronutrient group versus a 0% change in the placebo group (P = 0.01). The mean HIV-1 RNA decreased in the micronutrient supplementation group, although not significantly. Neuropathy scores improved in the micronutrient group by 42% compared with a 33% improvement in the placebo arm. This difference did not reach statistical significance. Fasting serum glucose, insulin, and lipids were not adversely affected in the patients taking the micronutrients. CONCLUSIONS: Micronutrient supplementation can significantly improve CD4 cell count reconstitution in HIV-infected patients taking HAART. The micronutrient supplement tested was well tolerated and may hold promise as an adjuvant therapy in the treatment of HIV. Further investigation is warranted.
Due to control of florid and severe cases of protein-energy malnutrition, deficiencies of micronutrients in children have assumed public health importance. According to National Nutrition Monitoring Bureau of India, over 50% of apparently healthy looking children have subclinical or biochemical deficiencies of vitamin A, vitamins B2, B6, folate and vitamin C. Over two-third of children have clinical evidences of iron deficiency while deficiency of trace minerals like iodine and zinc is quite common in certain populations. Children have food preferences and they are quite fussy to take green leafy vegetables and fruits thus compromising their intake of micronutrients from dietary sources. The full genetic potential of the child for physical growth and mental development may be compromised due to subclinical deficiencies of micronutrients which are commonly referred to as "hidden hunger". Micronutrients are required for the integrity and optimal functioning of immune system. Children with subclinical deficiency of micronutrients are more vulnerable to develop frequent and more severe common day-to-day infections thus triggering a vicious cycle of undernutrition and recurrent infections. A number of micronutrients are required for optimal physical growth and neuromotor development. Isolated deficiencies of micronutrients are rare in clinical practice and usually deficiencies of multiple micronutrients co-exist. The first 3 years of life are most crucial and vulnerable to the hazards of undernutrition. All efforts should be made so that preschool children are given a balanced and nutritious home-based diet. However, it has been shown that it is not possible to meet 100% requirements of recommended dietary allowances (RDA's) of micronutrients from dietary sources alone and most preschool children need administration of nutritional supplements to optimize their genetic potential for physical growth and mental development.
Deficiencies in intake of essential vitamins and minerals (commonly referred to as micronutrients) that are essential for efficient energy metabolism and other functions of the human body (commonly termed as micronutrients) are severe and widespread in many parts of the world. They cause an immeasurable burden on individuals, on health services, education systems and families caring for children who are disabled or mentally impaired. Studies by World Bank have shown that countries whose populations suffer from micronutrient deficiencies encounter economic losses as high as 5% of gross domestic product (GDP). The solution to control and prevent micronutrient deficiencies is available and affordable. At a national level, micronutrient malnutrition can be addressed by implementing programmes designed to educate people to diversify their diets (where appropriate foods are available), or by fortifying commonly eaten foods with the missing micronutrients or providing nutrient supplements through targeted distribution programmes. Food fortification is increasingly recognized as an effective means of delivering micronutrients. Fortification of foods can provide meaningful amounts of the nutrient at normal consumption of the food vehicle. Proper choice of fortificant and processing methods could ensure the stability and bioavailability of the nutrient. The level of fortification should take into account variations in food consumption to ensure safety for those at the higher end of the scale and impact for those at the lower end. Fortification needs to be supported by adequate food regulations and labeling, quality assurance and monitoring to ensure compliance and desired impact. In industrialized countries food fortification has played a major role in the substantial reduction and elimination of a number of micronutrient deficiencies. Although a growing number of large scale fortification programmes in different parts of the world are beginning to demonstrate impact at the biochemical level and are leading to the elimination of several nutrient deficiencies, food fortification remains an underutilized opportunity in many developing countries where micronutrient malnutrition remains a public health problem.
The purpose of the present paper is to review the evidence in favour of food-based strategies to meet the challenges of micronutrient malnutrition in the developing world. Increasing dietary diversification is the most important factor in providing a wide range of micronutrients, and to achieve this objective in a development context requires an adequate supply, access and consumption of a variety of foods. Diets in developing countries generally lack many nutrients, including energy (inadequate amounts of food), so that strategies need to also emphasize an increase in total food intake, in addition to a greater variety. Agricultural and food policies tend to be oriented to primary agricultural productions, but they could also be formulated to promote and support home gardens and small livestock production for the explicit purpose of increasing the household consumption of micronutrient-rich foods. The adoption of 'desirable' dietary patterns for nutrition improvement, e.g. appropriately formulated to meet micronutrient needs, could be used in the formulation of agricultural policies and programmes. This process could be achieved through support for integrated farming systems oriented to assuring household food security, but also based on a variety of foods that will meet total dietary (including micronutrient) needs. Thus, availability of energy-rich staples, animal and/or fish as major sources of protein, and vitamin-, mineral- and phytonutrient-rich fruit and vegetables could constitute the types of production envisaged. The cultivation of edible indigenous plants as additional sources of micronutrients could also be added. The low bioavailability of some key micronutrients from foods, such as Fe, are substantially enhanced with the right food combinations and with appropriate food processing and preparation techniques. Simple appropriate technology for the preservation of micronutrient-rich foods would need further development and promotion for their year-round availability. Linking community development policies to national programmes for the alleviation of hunger and malnutrition, with an emphasis on increasing the variety of foods consumed, is probably the best strategy for improving micronutrient malnutrition sustainably.