Iron deficiency and risk factors for lower iron stores in 6-24-month-old New Zealanders.

OBJECTIVES: To determine the prevalence of biochemical iron deficiency and identify factors associated with ferritin levels among 6-24-month-old urban South Island New Zealand children. DESIGN: Cross-sectional survey conducted from May 1998 to March 1999. SETTING: The cities of Christchurch, Dunedin and Invercargill. SUBJECTS: A total of 323 randomly selected 6-24-month-old children participated (response rate 61%) of which 263 provided a blood sample. METHODS: A complete blood cell count, zinc protoporphyrin, serum ferritin and C-reactive protein were measured on nonfasting venipuncture blood samples, 3-day weighed food records and general questionnaire data were collected. RESULTS: Among children with C-reactive protein<10 mg/l (n=231), 4.3% had iron deficiency anaemia, 5.6% had iron deficiency without anaemia, and 18.6% had depleted iron stores, when a ferritin cutoff of < or =12 g/l was used. Age (negative), sex (girls>boys), ethnicity (Caucasian>non-Caucasian), weight-for-age percentiles (negative) and birth weight (positive) were associated with ferritin after adjusting for infection and socioeconomic status. When current consumption of iron fortified formula and >500 ml of cows' milk per day were included, these were associated with a 22% increase and 25% decrease in ferritin, respectively (R2=0.28). CONCLUSIONS: The presence of suboptimal iron status (29%) among young New Zealand children is cause for concern, even though severe iron deficiency is rare, because children with marginal iron status are at risk of developing severe iron deficiency if exposed to a physiological challenge.

Risk of suboptimal iron and zinc nutriture among adolescent girls in Australia and New Zealand: causes, consequences, and solutions.

Surveys in Australia, New Zealand and other industrialised countries report that many adolescent girls have dietary intakes of iron and zinc that fail to meet their high physiological requirements for growing body tissues, expanding red cell mass, and onset of menarche. Such dietary inadequacies can be attributed to poor food selection patterns, and low energy intakes. Additional exacerbating non-dietary factors may include high menstrual losses, strenuous exercise, pregnancy, low socioeconomic status and ethnicity. These findings are cause for concern because iron and zinc play essential roles in numerous metabolic functions and are required for optimal growth, immune and cognitive function, work capacity, sexual maturation, and bone mineralization. Moreover, if adolescents enter pregnancy with a compromised iron and zinc status, and continue to receive intakes of iron and zinc that do not meet their increased needs, their poor iron and zinc status could adversely affect the pregnancy outcome. Clearly, intervention strategies may be needed to improve the iron and zinc status of high risk adolescent subgroups in Australia and New Zealand. The recommended treatment for iron deficiency anaemia and moderate zinc deficiency is supplementation. Although dietary intervention is often recommended for treating non-anaemic iron deficiency and mild zinc deficiency, it is probably more effective and appropriate for prevention than for the treatment of suboptimal iron and zinc status. Many of the strategies for enhancing the content and bioavailability of dietary iron are also appropriate for zinc.

Selenium and zinc status are suboptimal in a sample of older New Zealand women in a community-based study.

The importance of selenium and zinc in the immune functioning of the aged is widely recognized. Seniors in New Zealand are at particularly high risk of low selenium status because of the low selenium soil environment. The zinc status of the New Zealand elderly has never been assessed. In this cross-sectional study, the biochemical selenium, zinc and lipid levels, physical functional capacity and dietary intakes of 103 randomly selected free-living New Zealand women (mean age +/- SD, 75 +/- 3 y) were assessed. Among nonusers of selenium supplements (n = 80), 80% [95% confidence interval (CI): 70; 88%] had plasma selenium levels (0.85 +/- 0.23 micromol/L) below 1.00 micromol/L [ approximately 10% below mean plasma selenium necessary for full expression of glutathione peroxidase (GPx) activity in New Zealand subjects]. Plasma selenium was strongly correlated with GPx: r = 0.56; P < 0.0001. For nonusers of zinc supplements (n = 88), serum zinc concentrations were 12.4 +/- 1.4 micromol/L, with 12% (95% CI: 6; 21%) having levels below the cut-off value (10.7 micromol/L). Estimated mean daily selenium and zinc intakes were 34 +/- 10 microg and 8.7 +/- 2.0 mg, respectively. Subjects in the highest tertile of a functional capacity index had higher biochemical zinc and selenium values than those in the lowest tertile (P < 0.05). The correlation between plasma selenium and GPx indicates that selenium intake in these women is still insufficient for full expression of GPx activity. Lower serum zinc levels also appear to be prevalent. Because a suboptimal trace element status may be more common among those with a poor physical functioning, promotion of the consumption of nutrient dense foods or supplements to improve selenium and zinc status of elderly women in New Zealand may be beneficial.

Complementary foods for infant feeding in developing countries: their nutrient adequacy and improvement.

OBJECTIVE: To assess the energy and nutrient adequacy of a variety of complementary foods used in parts of Africa, India, Papua New Guinea, the Philippines and Thailand. METHOD: The energy, nutrient and anti-nutrient (dietary fibre and phytic acid) content (per 100 g as eaten, per 100 kcal, and per day) of twenty-three plant-based complementary foods consumed in developing countries was calculated from food composition values based on chemical analysis for the trace minerals, non-starch polysaccharide and phytic acid, and the literature. Results were compared with the estimated nutrient needs (per day; per 100 kcal) from complementary foods for infants 9-11 months, assuming a breast milk intake of average volume and composition and three complementary feedings per day, each of 250 g. RESULTS: Complementary foods should provide approximately 25-50% of total daily requirements for protein, riboflavin and copper; 50-75% for thiamin, calcium and manganese; and 75-100% for phosphorus, zinc and iron. Most or all appear to meet the estimated daily nutrient needs (per day; per 100 kcal) from complementary foods for protein, thiamin and copper (per day), but not for calcium, iron, and in some cases zinc, even if moderate bioavailability for iron and zinc is assumed. Some of those based on rice are also inadequate in riboflavin (per day; per 100 kcal). CONCLUSIONS: Even if strategies to improve the bioavailability of iron and zinc are employed, they are probably insufficient to overcome the deficits in calcium, iron and zinc. Therefore, research on the feasibility of fortifying plant-based complementary foods in developing countries with calcium, iron and zinc is urgently required.

PIP: At about age 6 months, the supply of energy and some nutrients from breast milk no longer fully meets an infant's nutritional needs. Complementary foods must therefore be provided. In many developing countries, cereals or starchy roots and tubers are used as a basis for such additional foods. Findings are presented from a study conducted to assess the energy and nutrient adequacy of a variety of complementary foods used in parts of Africa, India, Papua New Guinea, the Philippines, and Thailand. The energy, nutrient, and anti-nutrient content of 23 plant-based complementary foods consumed in developing countries was calculated from food composition values based upon chemical analysis for trace minerals, non-starch polysaccharide and phytic acid, and the literature. Results were compared with the estimated nutrient needs from complementary foods for infants aged 9-11 months, assuming a breast milk intake of average volume and composition and 3 complementary feedings per day, each of 250 g. Complementary foods should provide approximately 25-50% of total daily requirements for protein, riboflavin, and copper; 50-75% for thiamin, calcium, and manganese; and 75-100% for phosphorous, zinc, and iron. While most or all of the foods appear to meet the estimated daily nutrient requirements of complementary foods for protein, thiamin, and copper, they do not for calcium, iron, and, in some cases, zinc, even if moderate bioavailability for iron and zinc is assumed. Some of the foods based upon rice are also inadequate in riboflavin.

Nutrition intervention strategies to combat zinc deficiency in developing countries.

Widespread zinc deficiency is likely to exist in developing countries where staple diets are predominantly plant based and intakes of animal tissues are low. The severe negative consequences of zinc deficiency on human health in developing countries, however, have only recently been recognized. An integrated approach employing targeted supplementation, fortification and dietary strategies must be used to maximize the likelihood of eliminating zinc deficiency at a national level in developing countries. Supplementation is appropriate only for populations whose zinc status must be improved over a relatively short time period, and when requirements cannot be met from habitual dietary sources. As well, the health system must be capable of providing consistent supply, distribution, delivery and consumption of the zinc supplement to the targeted groups. Uncertainties still exist about the type, frequency, and level of supplemental zinc required for prevention and treatment of zinc deficiency. Salts that are readily absorbed and at levels that will not induce antagonistic nutrient interactions must be used. At a national level, fortification with multiple micronutrients could be a cost effective method for improving micronutrient status, including zinc, provided that a suitable food vehicle which is centrally processed is available. Alternatively, fortification could be targeted for certain high risk groups (e.g. complementary foods for infants). Efforts should be made to develop protected fortificants for zinc, so that potent inhibitors of zinc absorption (e.g. phytate) present either in the food vehicle and/or indigenous meals do not compromise zinc absorption. Fortification does not require any changes in the existing food beliefs and practices for the consumer and, unlike supplementation, does not impose a burden on the health sector. A quality assurance programme is required, however, to ensure the quality of the fortified food product from production to consumption. In the future, dietary modification/diversification, although long term, may be the preferred strategy because it is more sustainable, economically feasible, culturally acceptable, and equitable, and can be used to alleviate several micronutrient deficiencies simultaneously, without danger of inducing antagonistic micronutrient interactions. Appropriate dietary strategies include consumption of zinc-dense foods and those known to enhance zinc absorption, reducing the phytic acid content of plant based staples via enzymic hydrolysis induced by germination/fermentation or nonenzymic hydrolysis by soaking or thermal processing. All the strategies outlined above should be integrated with ongoing national food, nutrition and health education programmes, to enhance their effectiveness and sustainability, and implemented using nutrition education and social marketing techniques. Ultimately the success of any approach for combating zinc deficiency depends on strong advocacy, top level commitment, a stable infrastructure, long term financial support and the capacity to control quality and monitor and enforce compliance at the national or regional level. To be cost effective, costs for these strategies must be shared by industry, government, donors and consumers.

The zinc nutriture of preschool children living in two African countries.

The zinc nutrition of rural Malawian children (24 females, 33 males; age 62 +/- 10 mo) consuming cereal-based diets was compared with that of rural Ghanaian children (43 females, 33 males; age 59 +/- 10 mo) consuming cereals or starchy staples, using hair zinc concentrations, growth and body composition indices, and dietary intakes. Intakes of energy, protein, Ca, Zn, dietary fiber and phytate at two seasons of the year were estimated from 3-d weighed food records, using analyzed and literature food composition values. The mean annual intakes of energy (5419 +/- 1081 vs. 4698 +/- 885 kJ), protein (31.8 +/- 7.0 vs. 24.1 +/- 6.8 g), Zn (7.4 +/- 1.9 vs. 5.1 +/- 1.1 mg) and phytate (1899 +/- 590 vs. 604 +/- 151 mg), and the mean molar ratios of [phytate]/[Zn] and [Ca] x [phytate]/[Zn] mmol per MJ (25 +/- 4 vs. 12 +/- 2 and 44 +/- 13 vs 20 +/- 8 mmol/MJ), were higher for Malawian than for Ghanaian children. More Malawian than Ghanaian children had [phytate]/[Zn] > or = 15 (72% vs. 0%) and were severely stunted (57 vs. 28%). Ninety-four percent of children in Malawi and 83% in the Ghanaian village of Slepor had low hair Zn concentrations (< 1.68 mumol/g) compared with 39% in Gidantuba, Ghana. In Gidantuba, children with low hair Zn concentrations had low upper-arm-muscle-area-for-age and upper-arm-muscle-area-for-height Z-scores. The high intakes of phytic acid relative to zinc in Malawi suggest that these children were at greater risk for inadequate zinc nutriture than their Ghanaian counterparts.

PIP: A study of 57 children aged 44-78 months living in Chilunga village in Zomba District, Malawi, and of 76 children aged 42-80 months living in the villages of Slepor and Gidantuba in Greater Accra in Ghana aimed to determine intakes of zinc and other dietary components influencing zinc bioavailability. Children from Malawi had higher mean annual intakes of energy (5419 kJ vs. 4698 kJ; p .05), and phytate (1899 mg vs. 604 mg; p .05) and higher mean molar rations of [phytate]/[zinc] and [calcium] x [phytate]/[zinc] mmol per megajoule (25 mmol/MJ vs. 12 mmol/MJ and 44 mmol/MJ vs. 20 mmol/MJ, respectively; p .05) than the children from Ghana. A higher proportion of children from Malawi had a molar ratio of [phytate]/[zinc] of at least 15 (72% vs. 0; p .05). Malawian children were more likely to be severely stunted than the Ghanaian children (57% vs. 28%; p .05). The median hair zinc concentration of children living in Gidantuba was significantly higher than that of children living in Slepor and in Malawi (1.99 mcmol/g vs. 1.42 mcmol/g, respectively; p .05). Further, a higher percentage of children in Slepor and Malawi had lower hair zinc concentrations than those in Gidantuba (83% and 94%, respectively vs. 39%; p .05). The children in GIdantuba with low hair zinc concentrations exhibited low upper-arm-muscle-area-for-age (-0.71) and upper-arm-muscle-are-for-height Z scores (-0.10). The diets in Malawi were cereal-based while those in Ghana consisted of starch staples with relatively low nutrient and phytate densities and fermented cereals with relatively low densities of phytate relative to zinc. The high intakes of phytic acid relative to zinc in Malawian children indicated that they faced a greater risk for insufficient zinc nutrition status than Ghanaian children. The researchers called for a study to determine whether zinc supplementation would improve zinc nutrition status in children in Ghana and Malawi

Cognitive style and perception: the relationship between category width and speech perception, categorization, and discrimination.

Category width, as defined by Pettigrew's (1958) Category Width Scale, is a cognitive variable that purportedly reveals individual differences in categorization strategy. Subjects differ in terms of broadness and narrowness of judgments of category width--to what extent they will accept exemplars as good instances of a category. We tested the hypothesis that category width would be related to how subjects behave in different speech perception tasks. Differences found between extremely broad and narrow categorizers on such tasks would be helpful in understanding the nature of the perceptual and cognitive processes underlying the category width distinction. No effects attributable to category width were found when results were analyzed in terms of subjects' (a) discrimination and feature evaluation of auditory and visual information in speech events, (b) integration of these sources of information, (c) the process of decision, and (d) subjective preference for a two-choice versus a nine-choice response method. The results from both male and female and broad and narrow categorizers supported the predictions made by a fuzzy logical model of perception (FLMP). In the FLMP, people have access to continuous information about each feature of a stimulus, they make independent evaluations of each feature based on this information, the various features are integrated, and a decision is made based on the relative support for the viable alternatives. Given the common processes involved in speech and other pattern perceptual-recognition tasks, we conclude that fundamental processes involved in pattern recognition are unlikely to vary with personality measures, such as category width.

Selenium intakes of children from Malawi and Papua New Guinea consuming plant-based diets.

Dietary selenium intakes were determined over three seasons for 66 children aged 4-6 y in rural Malawi, and at one season for 67 children aged 6-10 y in rural Papua New Guinea. The selenium content of the foods consumed was assessed using instrumental neutron activation analysis. Median intakes of selenium for the Malawian children were 20 micrograms per day, 21 micrograms per day, and 15 micrograms per day at harvest, postharvest, and preharvest seasons, respectively. More than 43% of the Malawian intakes were below the U.S. Recommended Dietary Allowances for 4-6 y olds (20 micrograms per day). Median intake of Se for the Papua New Guinean children was 20 micrograms per day, with 87% of the intakes below the recommended level for 7-10 y olds (30 micrograms per day). Statistical comparisons of selenium intakes over three seasons for the 51 children present in all survey periods revealed that mean intakes were not significantly different in survey periods one and two, but decreased significantly in survey period three, when expressed per day (p less than 0.002), per MJ (p less than 0.003), or per kg (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)