Dietary phytate × calcium/zinc millimolar ratios and zinc nutriture in some Ontario preschool children

Abstract

Millimolar ratios of phytate/Zn, Ca x phytate/Zn, and Ca x phytate/Zn per 4.2 MJ were calculated from 3-d weighed-food records collected from 62 male (M) (mean age: 58 +/- 7 mo [mean +/- SD]) and 44 female (F) (mean age: 58 +/- 6 mo) preschool children from Southern Ontario. Food-composition values for phytate were based on laboratory analysis and the literature. No gender differences existed for median millimolar ratios of phytate/Zn (median: M, 5.3; F, 5.3), and Ca x phytate/Zn per 4.2 MJ (M, 68.1; F, 59.5), but median intakes of phytate (M, 399; F, 333 mg/d) and median millimolar ratios of Ca x phytate/Zn (median: M, 102.1; F, 72.3; p less than 0.01) were higher for boys than for girls. Of the children, only two (1M, 1F) and 22 (17 M, 5F) had millimolar ratios of phytate/Zn and Ca x phytate/Zn per 4.2 MJ, respectively, that were above critical values. Millimolar ratios of Ca x phytate/Zn (p = 0.06) and Ca x phytate/Zn per 4.2 MJ (p = 0.05) were higher in boys with hair zinc less than 1.07 mumol/g v greater than or equal to 1.07 mumol/g. Analysis of variance showed that height was influenced by an interaction between millimolar ratios of Ca x phytate/Zn per 4.2 MJ and sex (p = 0.0007), when age and midparent height were treated as covariates. Results suggest that dietary Ca x phytate/Zn millimolar ratios, when expressed per 4.2 MJ, influenced the zinc nutriture of these Southern Ontario boys.

Dietary phytate intake inhibits the bioavailability of iron and calcium in the diets of pregnant women in rural Bangladesh: a cross-sectional study

“…Phytate might be exerting its inhibitory effect on the bioavailability of calcium, iron, and zinc from the diet of those pregnant women who had molar ratios above the cut-off points. The recommended critical values are as follows: (phytate to calcium) > 0.24 for calcium [34], (phytate to iron) > 1 for iron [35], (phytate to zinc) > 15 for zinc [36], and (phytate × calcium)/zinc >200 for the combined effect of phytate and calcium on zinc [37] were used in this study. The molar ratios of phytate to zinc, calcium, and iron are calculated as the millimoles of phytate intake per day divided by the millimoles of zinc, calcium, and iron intake per day, respectively.…”

“…The molar ratio of (phytate × calcium) to zinc was used to predict the synergistic effect of both phytate and calcium on zinc absorption [37,50]. When considering the low calcium intake of the rural pregnant women, (phytate × calcium) to zinc molar ratio might not be a good indicator for predicting the interaction of phytate and calcium to zinc absorption [23].…”

The impact of rapid economic growth and globalization on zinc nutrition in South Korea

“…As regards increased relative risk of Zn deficiency, a low absorption efficiency for Zn has been associated with a phytate:Zn molar ratio of .15 (26) . By 1998, the dietary phytate:Zn molar ratio (8?2) was more comparable with the diets of Westernized countries than with traditional diets of Asian countries (27) . Critically, however, it is the urban populations that are driving this decline in phytate: Zn ratios and the rural populations, which tend to be much less affluent, have been less influenced by changes in national economic status and retain a more restricted traditional Korean diet (4) .…”

Selected Mineral Intakes of Adult African-Americans in the Washington, DC Area

“…A provisional molar ratio of 0.2 was suggested as the ratio above which marginal zinc deficiency might occur. This ratio has been used as related to human zinc nutriture (Gibson et al, 1991). The median phytate 1 calcium: zinc molar ratio for the daily diets of the subjects of this study was 0.097, although three exceeded 0.2.…”