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European Journal of Clinical Nutrition (1999) 53, 189±194 ß 1999 Stockton Press. All rights reserved 0954±3007/99 $12.00 http://www.stockton-press.co.uk/ejcn Nutrient intake and iron status of Australian male vegetarians AK Wilson1 and MJ Ball1* School of Nutrition and Public Health, Deakin University, Melbourne, Australia Objective: The study was designed to investigate the iron intake and status of Australian, male vegetarians aged between 20 and 50 y. Design: Cross-sectional comparison of male vegetarians and age=sex matched omnivores. Setting: Free-living community subjects. Subjects: 39 ovolactovegetarians, 10 vegans and 25 omnivores were recruited by local advertisement. Outcome measures: A 12-d semiquantitative dietary record to assess iron and zinc intake. Iron status was assessed by measurement of serum ferritin and haemoglobin concentrations. Results: Mean (s.d.) daily iron intakes of both the ovolactovegetarians (20.4 (7.7) mg=d) and vegans (22.9 (6.2) mg=d), were signi®cantly higher than the omnivores' intake of 15.8 (4.5) mg=d. Ovo-lactovegetarians and vegans had signi®cantly (P < 0.001 and P < 0.05, respectively) lower serum ferritin concentrations than omnivores: mean (s.d.): 64 (46.9), 65 (49.9) and 121 (72.5) ng=ml, respectively. Signi®cantly more ovolactovegetarians and vegans than omnivores had serum ferritin concentrations below 25 ng=ml and below 12 ng=ml (P < 0.05). A higher proportion of omnivores had concentrations above 200 ng=ml (P < 0.05). The differences in serum ferritin concentrations between the vegetarians and omnivores remained signi®cant even after exclusion of iron supplement users. Conclusion: Australian male vegetarians had iron intakes higher than those of omnivores and above recommended levels, but their iron status was signi®cantly lower. Sponsorship: Deakin University. Descriptors: dietary iron; ferritin; iron status; vegetarianism Introduction Compared to omnivores, vegetarians have been reported to have a lower incidence of a number of chronic diseases, such as coronary heart disease (Havala & Dwyer, 1993), diabetes, osteoporosis, arthritis, kidney stones and some cancers (Dwyer, 1988). In addition, vegetarians generally have lower blood pressure and body weight closer to desired levels (Dwyer, 1988). These factors may be attributed to several dietary differences between omnivores and vegetarians and also to many positive lifestyle practices of vegetarians. As demonstrated by Burr and Butland (1988) it is dif®cult to determine which aspects of the vegetarian diet and lifestyle are protective. However, despite these health bene®ts, the vegetarian diet has been associated with vitamin B12 , ribo¯avin, vitamin D, calcium, zinc and iron de®ciencies (Gibson, 1990; Dwyer, 1991; Havala & Dwyer, 1993). Owing to the physiological importance of iron and zinc, the adequacy of vegetarian diets with respect to both minerals has been the focus of study by several investigators (Latta & Liebman, 1984; Levin et al, 1986; Alexander et al, 1994; Donovan & Gibson, 1996). Dietary iron intake is a concern in vegetarians, as animal foods are the exclusive source of haem iron, which is the most bioavailable form of dietary iron with an absorption ef®ciency of 15 ± 25% (Monsen et al, 1978; Winston, 1994). Non-haem iron, which is found in fruit, vegetables, cereals, dairy products and eggs (Monsen et al, 1988; Winston, 1994), is *Correspondence: M Ball, School of Nutrition and Public Health, Deakin University, Melbourne, Australia. Received 22 August 1998; revised 28 September 1998; accepted 12 October 1998. the only form of iron in vegetarian diets and is less bioavailable. In addition, food components that may limit the bioavailability of non-haem iron are typically present in high amounts in vegetarian diets. These components include phytates (Oberleas & Harland, 1981; Hallberg et al, 1987; Ferguson et al. 1989), phenolic compounds (Brune et al, 1989), calcium (Freeland Graves et al, 1980; Gibson, 1990) and ®bre (Freeland Graves et al, 1980). The Australian Recommended Daily Intake (RDI) for iron is 12 ± 15 mg for adolescents and menstruating women, and 7 mg for men and post-menopausal women (NHMRC, 1991). However, owing to the variation in iron bioavailability of different foods and in diets with various food combinations (Winston, 1994), assessment of adequacy of iron intake in terms of meeting RDIs is a dif®cult task and subject to considerable error. The daily zinc requirement for adults has been set in the range of 6 ± 12 mg (NHMRC, 1991). In the Australian National Nutrition Survey (McLennan & Podger, 1995), the mean daily intake for adult men in Victoria (determined from diet recall and food frequency questionnaires (FFQ)) was 16.8 mg iron and 14.4 mg zinc. Several studies have been carried out to assess the adequacy of vegetarian iron intake. However, few have used diet records over a 12 to 14-d period, considered necessary to reliably determine iron intake (Basiotis et al, 1987). One such study, conducted by Alexander and colleagues in New Zealand, found the iron intake of both male and female vegetarians to be signi®cantly higher than that of omnivores (Alexander et al, 1994). This difference was particularly evident in males. These ®ndings are consistent with studies of Kelsay et al (1988) and others (Levin et al, 1986; McEndree et al, 1983). Studies by Alexander et al (1994) and others (Faber et al, 1986; Helman & Darnton Hill, 1987) assessed iron status by Nutrient and iron status of vegetarians AK Wilson and MJ Ball 190 measurement of the serum ferritin concentration, which is a measure of body iron status (Pilon et al, 1981). Results showed both male and female vegetarians to have signi®cantly lower serum ferritin levels than omnivores. In other studies, a signi®cant difference in iron status between vegetarians and omnivores was not shown when different methods of iron status assessment were used that are considered to have low sensitivity relative to the serum ferritin measurement (Latta & Liebman, 1984; Levin et al, 1986). A number of studies (Freeland Graves et al, 1980; Levin et al, 1986) have also assessed both the adequacy of vegetarian zinc intake and zinc status. Using a 24 h recall and FFQ as the diet assessment methods, results indicate there are no differences in vegetarian and omnivore zinc intake. However, a study of adolescents by Donovan and Gibson (1996) using 3 d weighed records shows a higher probability estimate of inadequacy for zinc and iron. Kadrabova et al (1995) also found plasma zinc concentration in vegetarians to be signi®cantly lower than in omnivores, although they provided no dietary data and plasma zinc may not be a particularly reliable measure of zinc status. Interestingly, the small study by Alexander et al (1994) raised particular concern for the iron status of vegetarian men, as a signi®cant proportion had serum ferritin levels below 12 ng=ml, indicating storage iron depletion. Despite these results, and the increasing incidence of male vegetarianism in Australia, most concern is typically given to women, with very little focus on men. In fact there has been only one published Australian study investigating iron status of vegetarian males (Helman & Darnton Hill, 1987), and none speci®cally addressing the adequacy of iron and zinc intake. The aim of this study was to assess the iron and zinc intake and iron status of healthy Australian male adult vegetarians using a 12 d semiquantitative food record and serum ferritin and haemoglobin measurements and to compare the results with age- and sex-matched omnivores. Methods Fifty vegetarians aged 20 ± 50 y were recruited in the Melbourne Metropolitan area, by advertisement in magazines, restaurants and health food shops. Twenty-®ve healthy omnivores, of the same age and similar body mass index (BMI) to the vegetarian subjects, were also recruited as `friend controls' of the vegetarians and by advertisement. For the purpose of this study, an ovolactovegetarian was de®ned as someone who never consumed red meat and consumed chicken or ®sh no more than once a week; a vegan was de®ned as someone who ate no meat, eggs or dairy products. Unless otherwise speci®ed, `vegetarian' includes both of these groups. An omnivore was someone who consumed red meat. Subjects were included only if they had been practising the particular diet for at least 6 months, were non-smokers, were in good health and were not using any medications regularly. Deakin University Ethics Committee approved this study, and each participant gave written informed consent. At an initial meeting, all subjects completed a questionnaire on their dietary habits, use of supplements and medications, previous de®ciencies related to diet, smoking habit and usual levels of exercise. Subjects were given detailed instructions on how to complete accurately a validated, 12 d semiquantitative food record (Edington et al, 1988) on either 12 consecutive days or from three sequences of 4 consecutive days followed by a few days rest but overall including 3 ± 4 weekend days. The importance of the 12 d recording period being representative of their normal eating patterns was explained to subjects. A set of electronic scales was provided for each subject to weigh food. In situations where weighing of food was not possible, subjects were instructed to estimate food portion sizes by referring to photographs in the food dairy. After completion of the diary, it was examined to clarify any queries. A fasting, venous blood sample was taken for estimation of serum ferritin and haemoglobin concentration. Weight and height were measured on a set of `Seca' digital scales, with minimal clothing and no shoes, and body mass index (BMI: weight (kg)=height (m2 )) was calculated. Waist and hip circumference were measured to the nearest millimetre using a standard, non-extensible measuring tape, and the waist=hip ratio was calculated. Sitting systolic and diastolic blood pressure were determined using an oscillomate 93 (Wallace Instruments Pty Ltd, Australia). Haematological measurements Haemoglobin was measured immediately using an electronic counter (HemoCue AB: Mallinckrodt Medical Pty Ltd, Nottinghill, Australia). Serum was separated by centrifugation at 4 C for 15 min (3000 rpm) after allowing the blood to clot at room temperature for 1 h. Serum samples were stored at 7 20 C for later analysis of serum ferritin. Serum ferritin measurements were performed at the `Inter-Lab' pathology laboratory by a two-site chemiluminometric immunoassay, using a Ciba Corning Automated Chemiluminescence System (ACS: 180 Australian Diagnostics Corporation Pty Ltd, Ciba Corning Diagnostics Corp, Scoresby). Diet analysis The food and beverage intakes recorded on the 12 days by each participant were entered into the dietary analysis program `Diet-3', whose data is based on Australian Food Composition Tables (Xyris 1987 ± 91, version 3.22). When composite foods eaten were not present on the database, recipes were entered. Statistical analysis All statistical analyses were performed using the Statistical Package for Social Sciences version 6.0 (SPSS Pty Ltd, Chicago, IL, USA). Nonparametric analyses using the Kruskal ± Wallis one-way ANOVA were performed to determine differences between omnivores, ovolactovegetarians and vegans for nutrient intake and haematological measurements. The Mann ± Whitney U-test was then performed with the Bonferroni adjustment (Matthews & Farewell, 1988) to identify which groups had signi®cant differences. Multiple regression analyses were performed to assess the relationship between dietary variables and serum ferritin concentrations. The Fisher exact test was used to demonstrate whether the three dietary groups were different with respect to having values below and above certain limits. Results The vegetarian group that completed the study consisted of 39 ovolactovegetarians and 10 vegans. The ovolactovegetarians and vegans had been following their dietary Nutrient and iron status of vegetarians AK Wilson and MJ Ball practices for a mean of 11 y (range 0.5 ± 44) and 6 y (range 1.5 ± 14), respectively. The 25 omnivore controls who participated did not differ signi®cantly from either the ovolactovegetarians or vegans with respect to age, BMI, waist=hip ratio, and blood pressure (Table 1), although their weight was higher than the ovolactovegatarians. The daily nutrient intakes of the three dietary groups are shown in Table 2. While total energy intake was similar for omnivores, ovolactovegetarians and vegans, the vegetarians derived a signi®cantly lower proportion of their energy from protein compared to omnivores. A much higher proportion of energy derived from carbohydrate compensated for this. Total fat intake and percentage of energy derived from fat were lower for ovolactovegetarians than for omnivores, as was saturated fat intake, with vegans consuming less than half the saturated fat of omnivores. The vegetarians consumed a higher percentage of total fat as polyunsaturated fat. Cholesterol intake was signi®cantly different between all three dietary groups, with the omnivores consuming the most and the vegans the least. Dietary ®bre was signi®cantly higher in vegetarians than in omnivores. Mean calcium intakes did not differ signi®cantly and were above the Australian RDI of 800 mg=d. Vitamin C intake of all groups was also well above recommended levels, with the vegans consuming signi®cantly greater amounts, with a mean of nine times the Australian RDI of 40 mg=d (NHMRC, 1991). The mean daily iron and zinc intakes of omnivores, ovolactovegatarians and vegans are shown in Table 3. Ovolactovegetarians and vegans had signi®cantly higher mean daily iron intakes than omnivores (P < 0.05 and P < 0.01, respectively). All the men had an intake above the RDI for men of 7 mg=d, the mean intakes for omnivores, ovolactovegetarians and vegans being 226%, 291% and 320% of RDI, respectively. Zinc intakes of the three groups were not signi®cantly different, with a high proportion of the omnivores, ovolactovegetarians and vegans having intakes below the Australian RDI of 12 mg=d (40%, 64% and 70%, respectively). The dietary sources of iron of the omnivores and vegetarians are indicated in Figure 1. Both ovolactovegetarians and vegans obtained their iron predominantly from cereals, vegetables, fruits, seeds and nuts. Cereals were also a main source of dietary iron for omnivores, but, in contrast to vegetarians, omnivores obtained a high proportion of iron from meat and meat products. Serum ferritin and haemoglobin concentrations (Table 4) were signi®cantly lower in ovolactovegetarians and vegans compared to those in omnivores (P < 0.001 and P < 0.05, respectively). The distribution of serum ferritin levels is shown in Figure 2. Differences between the three dietary groups were signi®cant, with more ovolactovegetarians and vegans than omnivores having serum ferritin concentrations below 25 ng=ml (P < 0.05). One ovolactovegetarian aged 23 years and two vegans aged 41 and 36 Table 1 Physical characteristics of omnivores, ovolactovegetarians and vegans; mean (s.d.) Group n Omnivores 25 Ovolactovegetarians 39 Vegans 10 Age (y) Weight (kg) Height (cm) BMI Systolic BP Diastolic BP 32.7 (8.8) 33.3 (8.2) 31.0 (5.6) 79.8 (9.5) 70.6* (11.2) 74.1 (14.2) 179.9 (5.9) 179.5 (7.9) 180.5 (8.0) 23.8 (2.7) 21.8 (2.5) 22.6 (3.1) 124.8 (15.7) 115.3 (12.6) 119.3 (9.5) 75.8 (8.4) 72.4 (12.8) 73.5 (9.6) *Signi®cantly different from omnivores, P < 0.001. Table 2 Comparison of daily nutrient intakes of male ovolactovegetarians vegans and omnivores; mean values or mean (s.d.) Nutrient Energy (MJ) [Kcal] Protein (g) % total energy Fat (g) % total energy Carbohydrate (g) % total energy Polyunsaturated fat (g) % total fat Monounsaturated fat (g) % total fat Saturated fat (g) %total fat Cholesterol (mg) Dietary ®bre (g) Sodium (g) Calcium (mg) Vitamin C (mg) Vitamin A (mg) Omnivore (n=25) Ovo-lactovegetarians (n=39) Vegans (n=10) 11.0 (1.9) [2632] 108 (17.2) 17.3 98.3 (31.8) 33.5 291 (77.4) 44.9 14.6 (8.4) 16.1 34.6 (11.7) 38.1 41.3 (13.3) 45.8 289 (96) 26.3 (7.7) 3.4 (0.7) 961 (263) 151 (93) 981 (326) 10.5 (2.4) [2548] 80 (16.4)b 15.5b 81.8 (28.1)a 28.2a 357 (92) 54.5b 19.7 (8.6) 27.5b 28.9 (15.0)a 38.3c 24.2 (9.1)b 35.0bd 102 (67)bc 49.8 (15.9)b 2.5 (0.8)b 899 (284) 218 (178)c 1266 (602) 11.6 (2.7) [2815] 81 (24.3)a 12.4b 88 (37.6) 28.0 413.4 (96.8) 59.1b 27.2 (16.0) 31.8b 35.4 (16.3) 44.1a 18.3 (7.5)b 24.1b 22 (28)b 63.8 (14.6)b 1.7 (9.5)b 911 (471) 360 (179)a 1661 (497)b Signi®cantly different from omnivores (aP < 0.01, bP < 0.001). Signi®cantly different between ovolactovegetarians and vegans (cP < 0.05, P < 0.01, eP < 0.001). a,b c,d,e 191 Nutrient and iron status of vegetarians AK Wilson and MJ Ball 192 Table 3 Daily intakes of iron and zinc of omnivores, ovolactovegetarians and vegans. Mean intakes for iron are given as a percentage of Australian RDI. The proportion of subjects with zinc intakes below the Australian RDI is also given Iron intake (mg=d) Zinc intake (mg=d) Group n Mean (s.d.) Range % of RDI Mean (s.d.) Range < RDI (%)b Omnivores Ovo-lactovegetarians Vegans 25 39 10 15.8 (4.5) 20.4 (7.7a 22.9 (6.2)b 8.2 ± 27.5 8.5 ± 42.3 15.2 ± 35.1 226 291 320 12.7 (2.4) 12.0 (4.4) 12.6 (3.8) 9.3 ± 16.9 5.8 ± 26.1 7.4 ± 18.1 40 64 70 a The mean iron intake as a percentage of the Australian RDI for iron of 7 mg=d. The percentage of subjects below the Australian RDI for zinc of 12 mg=d. a,b Signi®cantly different from omnivores (aP < 0.05, bP < 0.01). b Figure 1 Serum ferritin concentration (ng=ml) in vegetarians and omnivores. years had serum ferritin concentrations below 12 ng=ml (11, 8 and 10 ng=ml, respectively). All three subjects had iron and vitamin C intakes well above Australian RDIs and had not taken iron supplements, and the ovolactovegetarian consumed ®sh and chicken once or twice a month. More omnivores than vegetarians had serum ferritin concentrations above 200 ng=ml (P < 0.05). Three subjects, two ovolactovegetarians and one vegan, had haemoglobin concentrations (125, 129 and 120 g=l) below the reference range of 130 ± 150 g=l: one had a serum Figure 2 Dietary sources of iron in omnivores (j) and vegetarians (u). ferritin concentration of 153 ng=ml (in the normal range), while the other two subjects had low concentrations. Eight ovolactovegetarians and two omnivores were either currently taking iron supplements or had taken them in the previous two years. The serum ferritin concentrations of this group ranged from 24 to 117 ng=ml. Twenty-one vegetarians (including 4 who also took iron supplements) currently took a vitamin supplement that did not contain iron. Additionally, 11 ovolactovegetarians consumed either ®sh a few times a year or chicken once or twice a month (three of whom also took iron supplements). After exclusion of all iron-supplement users, and of ovolactovegetarian ®sh=chicken eaters the serum ferritin levels of omnivores remained signi®cantly higher than those of the ovolactovegetarians (P < 0.001) and vegans (P < 0.01). Multiple regression analysis showed there was no signi®cant correlation between age, alcohol, calcium, iron or ®bre intake and serum ferritin concentrations for the vegetarians and omnivores. However, a highly signi®cant, positive correlation was found between vitamin C intake and serum ferritin concentrations (r 2 0.52, P < 0.001). Discussion The adequacy of the vegetarian diet with respect to nutrient and vitamin intake has been the focus of a number of investigations. However, the present study is one of only two Australian studies that we are aware of that have assessed the adequacy of adult male vegetarian iron Nutrient and iron status of vegetarians AK Wilson and MJ Ball 193 Table 4 Subjects with serum ferritin in certain ranges and haemoglobin (g=L) concentrations in omnivores, ovo-lactovegetarians and vegans Group n Mean (s.d.) Omnivores Ovo-lactovegetarians Vegans 25 39 10 121 (73) 64 (47)c 65 (50)b HB (g=l) Range Ferritin < 12 ng=ml n (%)a Ferritin < 25 ng=ml n (%)a Ferritin > 200 ng=ml n (%)a Mean (s.d.) Range 44 ± 313 11 ± 238 8 ± 137 0 (0) 1 (3) 2 (25) 0 (0) 8 (20.5)b 3 (30) 5 (20) 1 (2.6)b 0 (0)b 173 (19) 140 (40)c 158 (28)b 144 ± 206 125 ± 195 129 ± 201 a Number and percentage of subjects with serum ferritin in the stated range. Signi®cantly different from omnivores (bP < 0.05, cP < 0.001). c,d status. Adequacy of iron intake was assessed using a quantitative food record over an adequate period of time, and serum ferritin and haemoglobin concentrations were measured as an indication of iron status. Iron intakes of both ovolactovegetarians and vegans were signi®cantly higher than those of omnivores, with all dietary groups having intakes well above the Australian RDI of 7 mg=d. A study conducted by Alexander et al (1994) on a vegetarian population in New Zealand consisting of 36 females and 14 males also found male vegetarian iron intake to be above recommended levels and higher than that of omnivores. The intakes (mean 20.4 mg=d and 20.2 mg=d, respectively), using the same dietary methodology, were very similar to those in our study. The differences in iron intake between vegetarians and omnivores are consistent with those found by Kelsay et al (1988), who compared iron intakes of Asian-Indian and American vegetarian groups to an American omnivore group. Other investigators ®nding similar results include Levin et al (1986), who studied an Israeli population consisting of 92 vegetarians and 113 omnivores, and McEndree et al (1983), who investigated a vegetarian group in Nebraska. A common methodological feature of our study and the studies conducted by Alexander et al (1994) and Kelsay et al (1988) is that nutrient intakes were assessed using 12 d and 14 d semiquantitative, diet records. This method of dietary assessment has been shown by Edington et al (1988) to have similar reliability to weighed food records, which are considered the most precise method. As calculated by Bingham (1987), 12 days are required to record individual, long-term iron intake within 10% of the mean. In contrast, studies that used records over shorter periods of 3 ± 7 days (Latta & Liebman, 1984; Faber et al, 1986) have not shown a difference in vegetarian and omnivore iron intake. Ovolactovegetarians obtained their dietary iron exclusively from non-haem iron sources such as fruits, vegetables, cereals, dairy products and eggs, while for vegans, fruit, vegetables and cereals were the only iron source. Although the amount of iron consumed was above the RDI, the actual amount absorbed may be considerably lower, owing to the low bioavailability of non-haem iron and food components inhibiting absorption. Iron status was thus measured and, as indicated by serum ferritin concentration, was signi®cantly lower in the vegetarians compared to the omnivores. Twenty-eight per cent of vegetarians had serum ferritin levels below 25 ng=ml, which may indicate the beginning of iron storage depletion (Bothwell et al, 1979). Furthermore, one ovolactovegetarian and two vegans had serum ferritin concentrations below 12 ng=ml, indicating depletion of storage iron (Cook et al, 1992). Although these subjects' haemoglobin levels were in the normal range, these storage levels might prove insuf®cient to provide for periods of stress or an episode of blood loss, and continued low availability of iron may result in iron de®ciency. The fact that iron intakes of all subjects with ferritin levels below 25 ng=ml were similar to or higher than those of other vegetarians and omnivores with ferritin concentrations in the normal range, indicates inter-person variation in absorption. Intake of ascorbic acid was well above recommended intakes for these individuals, and this is relevant as absorption of nonhaem iron is enhanced by consumption of ascorbic acid in the same meal (Cook & Monsen, 1977). However, overall ef®ciency of non-haem iron absorption is dependent on a balance between inhibiting components and ascorbic acid intake (Hallberg & Rossander, 1982). Vegetarians whose non-haem iron and ascorbic acid intakes are similar may have different levels of serum ferritin. Young Chinese Buddhist vegetarians have half the ferritin level of nonvegetarian fellow students, and this was at least partly attributed to their high phytate and soy intake (Shaw et al, 1995). The higher serum ferritin levels in omnivores can easily be explained by the consumption of the more ef®ciently absorbed haem iron. Interestingly, one ovolactovegetarian who ate chicken and ®sh a few times a year, and 20% of omnivores, had serum ferritin concentrations above 300 ng=ml. Such high levels may not be advantageous. In the Kuopio Ischaemic Heart Disease Risk Factor Study (Salonen, 1993), a mean serum ferritin concentration greater than 200 ng=ml was found to correspond to a 2.2-fold increased risk of acute myocardial infarction. Although these ®ndings have not been con®rmed in subsequent American studies (and disagreement in results could be explained by differences in serum cholesterol levels, as the risk due to elevated serum ferritin decreases when cholesterol levels are below 5 mmol=l), it may indicate relative advantage for most vegetarians. Signi®cant differences in iron status between vegetarians and omnivores are consistent with ®ndings by Alexander et al (1994) and others (Faber et al, 21986; Helman & Darnton Hill, 1987). Serum ferritin concentrations were lower for both vegetarians and omnivores in the New Zealand population compared to those in the Australian study, despite similar iron intakes (Alexander et al, 1994). This may be explained by the fact the Australian vegetarians consumed more vitamin C than the New Zealanders. Helman and colleagues (Helman & Darnton Hill, 1987) also studied an Australian vegetarian population (60 males and 60 females) but did not consider males and females separately, so comparison is not possible. There are, however, a number of papers reporting no signi®cant difference in vegetarian and omnivore iron status. In some cases this may be due to use of supplements by many subjects; for example, in the study by Locong (1986), 50% of the Nutrient and iron status of vegetarians AK Wilson and MJ Ball 194 vegetarians studied (22 females and 14 males) ate ®sh= poultry once a month and 61% took vitamin and mineral supplements. Animal ¯esh enhances iron absorption by stimulating the absorption of non-haem iron and providing some haem iron (Hallberg et al, 1986). In other studies, the method of iron status assessment used is less sensitive than serum ferritin (Pilon et al, 1981). Latta and Leibman (1984) assessed the iron status of 36 American male vegetarians by determination of whole-blood hematocrit, plasma iron and total iron binding capacity, and there can be poor iron status when these parameters are normal. As in previous studies (Freeland Graves et al, 1980; Levin et al, 1980; Levin et al, 1986), zinc intakes in the ovolactovegetarian, vegans and omnivores were found to be similar. Dietary phytates (Oberleas & Harland, 1981), calcium and insoluble ®bre (Freeland Graves et al, 1980) inhibit zinc absorption, and the high content of these food components and the exclusion of animal meats from the vegetarian diet may lead to a low zinc status in vegetarians. In the present study, a high proportion of subjects in all three dietary groups had zinc intakes below the Australian RDI of 12 mg=d. Therefore, consideration should be given to measurement of zinc status in vegetarians who consume large amounts of calcium and ®bre and phytate-rich foods such as rye bread, apples, rice, oatmeal and wheat cereals (Turnlund et al, 1984). The present study demonstrates that vegetarians had intakes of most macronutrients, minerals and vitamins closer to Recommended Intakes than did omnivores, particularly with respect to quantity and type of fat intake, sodium, antioxidant vitamin and ®bre intake. This may provide health bene®ts, particularly with respect to coronary heart disease. However, more consideration needs to be given to iron status in these men, even when their intake appears to meet the RDI. In fact, the RDI may need to be higher than 7 mg for male vegetarians. Attention should be given to optimising non-haem iron absorption by education about meal planning. Main meals containing non-haem iron should be eaten in combination with foods high in ascorbic acid while high phytate, phenolic and calcium foods should generally be avoided at the same time. Acknowledgements ÐWe thank Professor Andy Sinclair, Duo Li and Neil Mann, RMIT for assisting in recruiting volunteers. References Alexander D, Ball MJ & Mann J (1994): Nutrient intake and haematological status of vegetarians and age-sex matched omnivores. Eur. J. Clin. Nutr. 48, 538 ± 546. Basiotis PP, Welsh SO, Cronin FJ, Kelsay JL & Mertz W. (1987): Number of days of food intake records required to estimate individual and group nutrient intakes with de®ned con®dence. J. Nutr. 117, 1638 ± 1641. Bingham S (1987): The dietary assessment of individuals; methods, accuracy, new techniques and recommendations. Nutr. Abstr. Rev. 7, 706 ± 742 Bothwell TH, Charlton RW & Cook JD (1979): In: Iron Metabolism in Man, TH Bothwell (ed). Blackwell Scienti®c: Oxford. Brune M, Rossander L & Hallberg L. 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