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This study showed that, in chickens, the negative effects of phytate-phosphorus in a low inorganic phosphorus diet could be completely reversed through the additive effects of reduced dietary calcium and increased cholecalciferol. In the future, perhaps greater reliance on more readily available plant phosphorus sources may be instituted in developing countries, where cheap sources of inorganic phosphorus are difficult to obtain.

The carcinogenicity of phytic acid 'Daiichi' (PA), a natural food additive, was examined in Fischer 344 rats of both sexes. PA was added to the drinking-water of groups of 60 male and 60 female rats at levels of 1.25 or 2.5% for 100-108 wk. There was a dose-dependent reduction in the mean final body weights of rats treated with PA. Necrosis and calcification of the renal papillae were observed in PA-treated rats, but not in the controls. The incidences of necrosis (calcification) were as follows: one (three) out of 57 males given 2.5% PA; one (none) out of 59 males given 1.25% PA; 10 (17) out of 55 females given 2.5% PA; six (six) out of 58 females given 1.25% PA. Renal papillomas occurred in three of the high-dose male rats, four of the high-dose female rats, and three of the low-dose female rats. The development of papillomas seemed to be related to calcification and necrosis of the renal papillae induced by PA. While many other tumours developed in all groups, including the controls, the organ distribution of these neoplasms and their histological characteristics did not differ significantly from those known to occur spontaneously in this strain of rats.

The image quality obtained with technetium-99mC aerosol (Technegas) was evaluated and compared with that obtained with 99mTc-phytate aerosol generated by a jet nebulizer. Fifty patients underwent ventilation scanning after inhalation of each aerosol (mean interval of 3 days). Four views (anterior, posterior, left and right posterior oblique) were recorded with 200 k precounts. Both sets of images were blindly compared for (i) qualitative evaluation of images, (ii) quantitation of penetration (PI) and heterogeneity (HI) indices and (iii) assessment of ventilation state. Peripheral penetration was the same in 64% of cases, greater with 99mTc-C in 27% and greater with 99mTc-phytate in 9%. The use of 99mTc-C led to fewer and less intense foci of bronchial or gastric activity. The differences for 99mTc-C and 99mTc-phytate, respectively, between mean PI (0.78 vs. 0.70) and HI (15 vs. 18) were not significant. Consideration of all the parameters indicates the overall superiority of 99mTc-C. The final interpretation of the lung ventilation scans was, however, similar with both tracers.

Intra-arterial infusion liver scintigraphy was performed in 11 patients with primary or metastatic liver tumor, and intraportal infusion liver scintigraphy was performed in 6 patients for prophylaxis of liver metastasis from colorectal cancer. 99mTc-Sn colloid or 99mTc-phytate was administered through the catheter of which tip was placed in the portal vein or the hepatic artery, and then liver image was obtained. When 99mTc-phytate was infused intra-arterially, significant amount of the infused tracer passed through the liver and we could not get sufficient information to assess the distribution of drug administered through the catheter. On the other hand, intraportal infusion liver scintigraphy using 99mTc-Sn colloid or 99mTc-phytate and intra-arterial infusion liver scintigraphy using 99mTc-Sn colloid revealed heterogeneity of liver uptake, tracer uptake in spleen, low uptake area corresponding to the liver tumor and high uptake area around it. The findings will be clinically useful, and these methods are thought to be helpful to confirm the satisfactory drug distribution.

The activities of phytase and alkaline phosphatase in the intestine gradually increased in parallel during development of rats, but the 70K and 90K subunits were expressed differentially; only the 70K subunit was detected at birth, whereas the 90K subunit appeared at the weaning period (3 weeks after birth). When rats were forced to wean at 18 days old and fed laboratory chow, the enzyme activity increased markedly and the 90K subunit appeared within 1 day. These findings suggest that weaning is involved in the change in the subunit composition. Increases in the enzyme activity and amount of the 90K subunit were significantly delayed by feeding weanling animals on casein diet, but induced significantly by feeding them on casein diet supplemented with phytate. Thus induction of the 90K subunit seems to be accelerated by intake of phytic acid in the diet. The Km value of the enzyme from suckling rats for phytate was 5.25 mM, while that of adult rats was 0.213 mM. In contrast, the Km value for p-nitrophenyl phosphate (PNPP) was constant during development. The phytase activity of suckling rats did not show a distinct pH-dependence. These findings suggest that the 90K subunit may play some important roles in expressing an efficient phytase activity.

The effects of a low-phytate barley-fiber concentrate on calcium, magnesium, and zinc balances and on apparent iron absorption were measured by balance experiments. During the three experimental periods of 22 d each, all subjects consumed the basal diet alone, the basal diet with 15 g barley fiber (high-fiber, high-protein diet), and a modified basal diet containing less protein with 15 g barley fiber (high-fiber, low-protein diet), respectively. The mean daily intake of the cations was 24.4, 25.4, and 22.9 mmol Ca; 10.4, 10.1, and 10.0 mmol Mg; 165.2, 166.8, and 119.3 mumol Zn; and 154.0, 186.2, and 154.0 mumol Fe, respectively. Mean balances were 0.2, 1.9, and -0.8 mmol Ca; 0.3, -0.2; and -0.5 mmol Mg; 3.0, -4.6, and -18.4 mumol Zn. The mean apparent iron absorption was 16.1, 5.4, and -23.2 mumol when these three diets, respectively, were consumed.

The diagnosis of leaks in pneumothorax was studied with radionuclide inhalation lung scan in animals. The animal pneumothorax models were made either by puncture or by operative method on nine dogs. The pneumothorax was proved by chest X-ray. The dogs were intubated and ventilated. Aerosol of 99mTc was delivered into the lung through tracheal cannula. 5-10 mGi: of 99mTc-phytafe with 150 ml of normal saline was used ultrasonics. The droplet size was estimated at 0.5-10 microns in diameter. The lung scan were obtained with GCA90B-gamma camera in dynamic or static way for about 0.5 hr. The air leaks (total 13) in tension pneumothorax were demonstrated by lung scan and were in accord with the fissures in the lung samples.

Five cases of heredopathia atactica polyneuritiformis (HAP--Refsum's disease) were treated by serial plasma exchanges. In all patients a reduction in calorie intake and body weight had been associated with a rise in plasma phytanic acid, followed by an exacerbation of the ataxia and neuropathy. Lowering the plasma phytanic acid by plasma exchange produced a rapid clinical improvement. The main indication for plasma exchange in HAP is a severe or rapidly worsening clinical condition. A lesser indication is failure of dietary management to reduce a high plasma phytanic acid level.

Three experiments were conducted to evaluate the effects of sodium aluminosilicate (SAS) on performance of chicks and laying hens fed diets varying in nonphytate P (NPP), phytate, and fiber content. In two chick growth experiments a corn and soybean meal diet and a phytate and fiber-free casein-dextrose diet were used. These diets contained .1% NPP and 1.1% Ca and were fortified with 0, .05, or .10% P from KH2PO4 and 0 or .5% SAS. A 3 x 2 factorial arrangement of treatments was used. Sodium aluminosilicate supplementation significantly (P less than .05) depressed growth of chicks fed the corn and soybean meal diets containing 0 or .05% supplemental AP. Sodium aluminosilicate addition decreased (P less than .05) tibia ash and total tibia P (tibia weight x P concentration) in both chick experiments, with the effect being greater for chicks fed the corn and soybean meal diet. In the laying hen experiment, birds were fed corn and soybean meal diets containing NPP levels of .1, .45, or 1.8% and SAS levels of 0 or 1.0%. Egg production and egg yield were depressed (P less than .05) by feeding diets containing .1 or 1.8% NPP, and egg specific gravity was decreased (P less than .05) by feeding 1.8% NPP. Addition of SAS to the .1% NPP diet caused a large reduction (P less than .05) in egg production, egg weight, and feed efficiency, whereas SAS supplementation of the 1.8% NPP diet had no significant effect. Sodium aluminosilicate supplementation increased (P less than .05) egg specific gravity for hens fed the .1 and 1.8% NPP diets.(ABSTRACT TRUNCATED AT 250 WORDS)

Some cereal by-products, such as bran, exhibit a high phytase activity that may enhance phytate P digestibility. This was studied in growing pigs fed a phytase-rich (1,200 IU/kg) diet containing 20% rye bran. The trial involved 12 animals; six were fed a control diet and six were fed a diet containing rye bran for 2 mo. Both diets contained the same levels of energy, protein, Ca (.7%) and total P (.4%). No inorganic P was added; thus, the dietary P was mainly phytic. Pigs fed the control diet, in contrast to those fed the diet containing rye bran, developed a P deficiency, as indicated by hypophosphatemia, hypophosphaturia, hyperhydroxyprolinuria, hypercalcemia, and hypercalciuria. Phosphorus from the rye bran diet was more completely absorbed (55 vs 36%) and retained (50 vs 36%) than that from the control diet. Calcium absorption was equal for the two diets, but Ca retention was higher in pigs fed rye bran than in controls. Pigs fed the rye bran diet showed greater bone density, ash content, and bending moments than controls. In conclusion, high dietary phytase levels or phytase-rich by-products increased phytate P availability and consequently improved bone scores.

The effects of maize-bran phytate and of a polyphenol (tannic acid) on iron absorption from a white-bread meal were tested in 199 subjects. The phytate content was varied by adding different concentrations of phytate-free and ordinary maize bran. Iron absorption decreased progressively when maize bran containing increasing amounts of phytate phosphorous (phytate P) (from 10 to 58 mg) was given. The inhibitory effect was overcome by 30 mg ascorbic acid. The inhibitory effects of tannic acid (from 12 to 55 mg) were also dose dependent. Studies suggested that greater than or equal to 50 mg ascorbic acid would be required to overcome the inhibitory effects on iron absorption of any meal containing greater than 100 mg tannic acid. Our findings indicate that it may be possible to predict the bioavailability of iron in a diet if due account is taken of the relative content in the diet of the major promoters and inhibitors of iron absorption.

Two rapid methods for fractionating the RBC into five or nine layers of increasing density are reported. These procedures have been used to monitor the decline of glucose-6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase (6PGD) activity during the process of red cell aging in normal subjects and in beta-thal carriers, to study transfused patients with G6PD and pyruvate kinase (PK) deficiency and to test the effects of inositol hexaphosphate (IHP) encapsulation on RBC subpopulations.

Absorptiometric, histomorphometric, and chemical analyses of bones from growing rats fed diets with low (0.2%, w/w), marginal (0.4%, w/w), or adequate (0.8%, w/w) calcium (Ca) content with or without phytate were compared. Phytate was added to each diet in a molar ratio of 19:1 to calcium. Male weanling Sprague-Dawley rats were fed one of the six diets for 8 weeks. At the end of 8 weeks, rats were killed, and mandibles, femurs, and tibias were removed. Bone density profiles were determined on the mandibles and femurs using single photon absorptiometry. Femurs were also used for calcium and phosphorus analyses. Tibias were used for histomorphometric analyses. Bone density of the femurs and mandibles increased as dietary Ca increased. The only effect of phytate addition measured was in the 0.8% calcium diet, where density was lower in rats fed the phytate-containing 0.8% calcium diet. Femur calcium concentration also increased as dietary Ca increased and was unaffected by addition of phytate. Femur phosphorus concentration was unaffected by dietary Ca levels but was increased by 10% when phytate was added to the diet. Bone density values were highly correlated with bone calcium and phosphorus levels (r = 0.94). Rats fed the 0.2% calcium diets had 20% lower mineralized bone area and 20% larger medullary cavity area than rats fed the other diets. Bone densitometry appears to be useful for determining changes in bone occurring in growing rats fed low, marginal, and adequate levels of dietary Ca. Bone density values also correlated well with chemically determined calcium and phosphorus concentrations and with histomorphometric data.

Two important factors that determine zinc nutriture are the amount of zinc provided by the food supply and the zinc content of the foods individuals eat. The amount of zinc provided by the U.S. food supply has varied between 11 and 13 mg/day/person since the beginning of the century. Currently, it is estimated that the U.S. food supply provides 12.3 mg zinc per person per day. Data from the Food and Drug Administration's Total Diet Study and the U.S. Department of Agriculture's Nationwide Food Consumption Survey of Individuals and year-long Beltsville diet study indicate that adult males select diets that contain 90% or more of the 1989 Recommended Dietary Allowance (RDA) for zinc, whereas women select diets that have less than 81% of the RDA for zinc. Zinc densities of the diets for men and women were similar, which suggests that the difference in total zinc intake is attributable to a difference in energy consumption. Consumption patterns that meet the RDA for zinc can be compatible with the recent National Academy of Sciences diet and health recommendations. The dietetic practitioner should encourage consumption patterns that include using zinc-rich foods in the form of poultry and lean meats and low-fat or nonfat dairy products; using grain products and legumes, particularly whole grains, which can make an important contribution to total zinc intake; and increasing physical activity to a moderately active level to increase energy and zinc intake.

The purpose of this 2 factorial designed study was to investigate the influence of citric acid on the availability of zinc from diets containing 140 g corn germs as a native phytate source (0.5% phytate in diet). Growing male rats with an average initial weight of 42 g were divided into 8 groups of 8 animals each. After a 7 d depletion period (2.4 micrograms Zn/g diet) the animals were fed ad libitum for 21 d a diet on the basis of egg white solid and corn germs. The diets were supplemented with zinc in order to obtain phytate:zinc molar ratios of 31, 20, 14, and 0 (control without corn germs, 11 micrograms Zn/g diet). Each diet was fed with and without a supplementation of 1% citric acid. A phytate:Zn molar ratio of 31:1 resulted in typical symptoms of zinc-deficiency like anorexia, alopecia and a significant depression of growth. These effects were apparently reduced by citric acid. The zinc concentration in serum and organs followed the graded levels of phytate:zinc molar ratios. Primary significant effects of the phytate:Zn molar ratio but also effects of citric acid and interactions between the 2 factors phytate:Zn and citric acid could be detected. Only total liver zinc but not liver zinc based on fresh matter was affected by the phytate:Zn molar ratio. In serum and tissues the activity of alkaline phosphatase showed a significant response to the phytate:zinc molar ratio. Furthermore the supplementation with citric acid increased the femur alkaline phosphatase and slightly reduced it in the liver. The concentrations of metallothionein in liver duodenum, jejunum and ileum were significantly affected by the phytate:Zn molar ratio.

Due to its high phytate content, the bioavailability of zinc in whole meal cereal products is distinctly lower as compared to foods of animal origin. The effect of reducing the phytate content of cereal products made from rye and wheat on growth, zinc content of femur and blood serum, as well as on the activity of serum alkaline phosphatase was investigated during a 3-week feeding trial in growing rats. The reduction of phytate was achieved by controlling the phytase activity originally present in cereals. By these treatments, the molar phytic acid/zinc ratio in the cereal products was reduced from 27-37 to 3-18. The four parameters under investigation showed a significant improvement in zinc bioavailability with decreasing phytic acid/zinc ratios. The relevance of these results for man and the value of the molar phytic acid/zinc ratio as an indicator of the bioavailability of zinc in foods are discussed.

Routine full blood counts and serum ferritin determinations were carried out after admission to hospital in 112 children which included a white caucasian group (n = 65) and two ethnic minority groups of West Indians (n = 24) and Asians (n = 23). In these 3 groups those children between the ages of 1 week and 6 months were found to have similar haemoglobin, mean corpuscular volume, and ferritin levels. In the remaining children (aged from 7 months to 14 years 5 months) serum ferritin levels were lower in the ethnic minority groups than in white caucasians, but the haemoglobin and mean corpuscular volume were not significantly different. Children with lower height centiles had reduced ferritin levels, irrespective of their ethnic origins. A nutritional survey between the ages of 7 months and 14 years 5 months showed that mean daily dietary intakes of energy, protein, and iron in white caucasions were similar to those in West Indian and Asian children. The differences noted were in larger phytate and fibre intakes in the ethnic minority groups. Asian diets appeared to differ in containing meat less often as a source of iron, while pulses and chapattis provided more phytate and fibre. It is suggested that dietary intakes of phytate and fibre are important in causing lower ferritin levels by reducing iron absorption.

An assay was conducted with young albino rats to compare the bioavailability of zinc contained in calcium- and in magnesium-precipitated tofu to zinc supplied as the carbonate in egg white diets. Relative availability of zinc from both tofu preparations was 51% as measured by weight gain and 36-39% for log micrograms tibia zinc accumulation. In a separate experiment with zinc supplied at 9 mg/kg in all diets, the effect of increasing dietary calcium on weight gain and tibia zinc accumulation was tested. Performance of tofu-fed rats relative to zinc carbonate-fed rats at 0.4, 0.7 and 1.2% calcium was, respectively: 92, 67 and 48% for weight gain, and 70, 58 and 61 for tibia zinc content.

This paper on confounding factors in the relationship between iron deficiency and brain function is mainly limited to nutritional factors, primarily factors that can contribute to the development of iron deficiency and that may have an independent direct action on brain function. Three theoretically possible confounders were found in a systematic search for dietary factors: 1) low intake of ascorbic acid, 2) excess of phytates, and 3) increased absorption of lead. Ascorbic acid has a marked effect on the bioavailability of dietary iron and is also known to directly influence various metabolic processes in the brain. Phytates inhibit the absorption not only of iron but also of zinc. An iron deficiency may thus be accompanied by a zinc deficiency which may affect mental performance. A state of iron deficiency may increase the absorption of lead from the diet, which in turn may affect brain function.

Microinjections of inositol hexakisphosphate (IP6), a metabolite of inositol recently found to occur in high concentrations in the brainstem, were made into the caudal portion of the nucleus tractus solitarii (NTS) of spontaneously breathing rats and cardiorespiratory parameters recorded for a 30 min test period. Microinjections of IP6, in the dose range of 100-500 pmol/rat, produced significant dose-related reductions in mean arterial blood pressure and respiratory rate. The onset for hypotensive action and respiratory depression following microinjections of IP6 was very rapid and a transient apnea could be elicited at the higher doses. Moreover, the sodium and calcium salts of IP6 were relatively equipotent in depressing cardiorespiratory parameters, with the exception of heart rate wherein the sodium salt elicited a much more pronounced bradycardia. These results confirm and extend the findings of a previous study suggesting that IP6 and closely related metabolites may act on extracellular receptors. Taken together, these data provide further support to the notion that inositol lipid signalling pathways may generate both intracellular and extracellular signals in the brain.

A prototype high-frequency ultrasonic nebulizer, coupled with a nebulization chamber, has been designed specifically to overcome the problem of inefficient and unpredictable radioaerosol delivery. The objective was to reduce mean particle size, increase aerosol concentration, and minimize dead space. Thirty-nine patients were studied, including 15 patients in significant respiratory distress. Delivery of the radioaerosol proved to be rapid, efficient, and reproducible, and excellent alveolar distribution patterns were obtained in all 39 patients. Minimal nonpathologic tracheal deposition occurred in five patients, but this did not interfere with the interpretability or diagnostic validity of the study. All other instances of airway aerosol deposition correlated with documented airway disease. The images obtained with this system are a reliable measure of ventilatory distribution and airway tubulence.

1. Iron absorption was studied in weanling rats using balance techniques from semi-synthetic diets containing dried white bread (60.5 g dietary fibre/kg. White & Southgate, unpublished results), brown bread (130.2 g dietary fibre/kg) or wholemeal bread (221.2 g dietary fibre/kg) at a level of 300 g/kg and compared with a control group given a diet containing added FeSO4 at a similar Fe level to that for the bread groups. The dried bread contained 6.2-6.4 g phytate/kg. 2. Absorption of Fe was significantly higher (P less than 0.001) in the control group (0.45) than in the White (0.28), brown (0.31) or wholemeal (0.24) groups. 3. A second experiment was carried out on 6-week-old rats in which the dried bread was extrinsically labelled with 59Fe and absorption from a single meal measured by both faecal excretion and incorporation of 59Fe into the blood. Control animals were given 59FeSO4 for comparison. 4. The excretion of 59Fe (% of administered dose) was significantly lower (P less than 0.001) in the control group (31) than in the white (48), brown (45) or wholemeal (47) groups. After 10 d the control group had significantly more 59Fe in the blood than the bread groups, but there were no differences between the bread groups. 5. It appears that wheat bran fibre itself has no effect on the retention of Fe from the diet in the rat, when supplied in amounts similar to those found in commercially-available bread.

The intravenous toxicity of phytic acid (inositol hexakisphosphate, IHP) has recently become of interest because of the potential for IHP incorporation into red blood cells to achieve a therapeutically useful shift in the hemoglobin-oxygen dissociation curve (Gersonde, K. and Nicolau, C., Blut, 39 (1979) 1). The observed acute intravenous toxicity of IHP in rodents is consistent with its recognized capacity to bind calcium. The toxic manifestations of intravenous IHP are a function of rate of infusion as well as total dose, with some seemingly anomalous variations which may related to compensatory mechanisms. The data suggest that significant alterations of plasma calcium and the toxic potential of such alterations are not likely to result from the administration of red blood cells with IHP incorporated.

1. Seventy-six students and staff at Robert Gordon's Institute of Technology weighed all items of food consumed for 1 week. 2. Mean phytate-phosphorus intakes ranged from 141 mg for female students to 237 mg for male students. Breakfast was proportionally a more important contributor to daily phytate intakes than to calcium, zinc, and energy intakes. Cereals were the most important contributors to the phytate at breakfast, whilst wholemeal and brown bread were more important at lunch and the evening meal. 3. The phytate: Zn molar ratio was distributed amongst meals similarly to the more complex ratio, (Ca x phytate):(Zn x energy) (CP:ZE); both ratios have been suggested as useful predictors of Zn availability. CP:ZE ranged more widely when calculated for meals than for days, and therefore some meals could be associated with poor Zn availability whilst others could compensate with higher availability. Subjects with the highest values for CP:ZE were mostly amongst the group of nutrition students.

A child with Refsum's disease presented with cardiac failure, marked muscle wasting, weakness and inco-ordination. Management with multiple plasma exchanges and dietary restriction of phytanic acid intake has reversed the disabling features of the disease, although levels still remain higher than target values. Low phytanic acid intake is being achieved by restriction of total fat to 10 to 12 g/day, while allowing free amounts of fruit and green vegetables.

The absorption of zinc from soy protein-containing meals was studied in healthy human subjects by means of extrinsic labelling with 65Zn and whole body counting. Three types of soy protein, a soy flour, a soy concentrate and a soy isolate, were used in two types of meals: one consisting of rice and meat sauce and the other of white or whole-meal bread. Thirty and 100% of the protein of the meat sauce and 50% of the protein of bread was replaced with the soy protein products. Replacement of 30% of the protein in meat sauce had a marginal effect on the percentage absorption of zinc, whereas the absolute amount of zinc absorbed was lower due to the lower zinc content in soy products than in meat. After total replacement of the meat protein, a significantly lower percentage and absolute absorption of zinc was observed. A lower absorption of zinc was observed when soy protein was added to white bread. The absorption of zinc from the whole-meal bread was low and did not change when 50% of the flour protein was replaced by soy protein. We conclude that the effect of soy protein on zinc absorption depends on the degree of replacement, the phytic acid and zinc content of the soy product and the protein content of the meal.

Dietary zinc, calcium, and phytate intakes of 66 rural Malawian children aged 4-6 y were determined during three seasons on the basis of weighed food records and analyzed food composition data. Height and weight measurements were also recorded and hair samples were collected for zinc analysis. Seasonal daily zinc, calcium, and phytate intakes of females ranged from 6.2 +/- 1.7 to 6.8 +/- 2.1 mg (mean +/- SD), from 335 +/- 170 to 401 +/- 257 mg, and from 1621 +/- 660 to 1729 +/- 592 mg, respectively and, for males, 7.0 +/- 1.7 to 8.0 +/- 2.3 mg, 342 +/- 164 to 473 +/- 310 mg, and 1857 +/- 530 to 2161 +/- 684 mg, respectively. Cereals provided greater than 42% of dietary zinc. Seasonal mean molar ratios of phytate to Zn and Ca x phytate to Zn [per 1000 kcal (4.2 MJ)] and the median Ca to phytate molar ratio ranged from 24 to 27, 151 to 188 mmol/1000 kcal (4.2 MJ), and 3.1 to 3.4, respectively. Over 78% of the children consumed diets with phytate-to-Zn and Ca x phytate.Zn-1 . 1000 kcal-1 molar ratios above values suggested to jeopardize zinc status. Correlations between hair zinc, phytate-to-Zn, and Ca x phytate.Zn-1 . 1000 kcal-1 molar ratios suggest that high phytic acid intakes may compromise zinc status in these children.

A study was undertaken to determine whether the reduction of the molar phytic acid/zinc ratio by enrichment of wholemeal and crispbread with zinc improves zinc availability to the same extent as does the reduction of phytic acid in whole meal cereal products. For three weeks, five diets (three samples of wholemeal bread and two samples of crispbread] were fed to growing rats. Significant increases in bone-zinc deposition and activity of serum alkaline phosphatase were induced by those bread samples in which the phytic acid/zinc ratio had been lowered either by enrichment with zinc or by reduction of phytic acid (enzymatic hydrolysis by adjusting the pH-value of the dough with lactic acid) when compared with untreated bread samples. Weight gain of the animals differed little between the groups. The results suggest that it is possible to improve zinc availability in wholemeal cereal products high in phytate by enrichment with zinc.

Nutrient intakes of 1,066 young women 18 to 24 years of age were estimated using a shortened nutrient data base (the University of California, Berkeley Minilist) containing 235 food items. The dietary data consisted of 24-hour recalls collected during the Second National Health and Nutrition Examination Survey (NHANES II). A cross-reference index, recipe file, and concentration factors were developed to substitute foods on the data base for the 1,267 foods reported by the young women. Estimates of energy, protein, fat, carbohydrate, and iron intakes using the NHANES II nutrient data base and the UCB Minilist were within 3% of one another, and had correlation coefficients above 0.97. Mean +/- S.E. daily intakes of copper, zinc, dietary fiber, and phytate, which are not included in the NHANES II data base, were estimated to be 1.16 +/- 0.02 mg, 8.11 +/- 0.14 mg, 13.2 +/- 0.3 gm, 395 +/- 14 mg, respectively. The values agree closely with other published values for young women's intakes. A shortened nutrient data base can be a valid tool for estimating intakes of populations.

A common gastrointestinal tract problem afflicting the elderly is that of reduced hydrochloric acid secretion by the stomach mucosa. This results in raised stomach pH values and in reduced activity of the digestive enzyme pepsin, which is responsible for the hydrolysis of dietary proteins to polypeptides. The effects of these alterations of the stomach on the digestion of high-fiber foods and resultant mineral bioavailability have not been defined. This paper reviews the effects of pH on the mineral-phytate, protein-mineral-phytate, and mineral-fiber interactions that would be present in high-fiber foods. Possible consequences of raised stomach pH values on mineral bioavailability from high-fiber foods are discussed.