Association between iron intake from different sources and risk of gestational diabetes mellitus： a retrospective cohort study / 上海预防医学

ObjectiveTo explore the association between total iron， iron supplements， dietary total iron， heme iron intake and the risk of gestational diabetes mellitus（GDM）. MethodsA total of 668 pregnant women who gave birth in one hospital in Shanghai during January 2020 to July 2021 were included in a retrospective cohort study. Baseline characteristics and data of iron supplements in second trimester were collected through a questionnaire. A simplified dietary frequency questionnaire was used to quantify the food intake in second trimester. Total iron， iron supplements， dietary total iron， and heme iron intake was classified into groups by quintile and median. The association between iron intake from different sources and risk of GDM was determined using logistic regression analysis. ResultsAfter correction for age， family history of diabetes， overweight / obesity before pregnancy， hemoglobin（Hb）in first trimester， energy， carbohydrate energy， protein， and free sugar， it showed no association between total iron intake and risk of GDM （P>0.05）， while elevated risk of GDM among women with high iron supplements intake （OR=1.65； 95%CI： 1.14‒2.39）， and decreased risk of GDM among those with high dietary total iron intake （OR=0.53； 95%CI： 0.35‒0.81）. However， no association was found between heme iron intake and risk of GDM （P>0.05）. ConclusionHigh dietary total iron intake may be a protective factor， while high iron supplements may be a risk factor for GDM. It suggests that pregnant women should carefully choose high-dose iron-containing supplements in the absence of iron deficiency， as dietary iron intake should be the priority.

Advances in bacterial Rieske non-heme iron ring-hydroxylating dioxygenases that initiate polycyclic aromatic hydrocarbons degradation / 生物工程学报

Polycyclic aromatic hydrocarbons (PAHs) are a class of persistent organic pollutants, which have received widespread attentions due to their carcinogenic and mutagenic toxicity. The microbial degradation of PAHs are usually started from the hydroxylation, followed by dehydrogenation, ring cleavage and step-by-step removal of branched chains, and finally mineralized by the tricarboxylic acid cycle. Rieske type non-heme iron aromatic ring-hydroxylating dioxygenases (RHOs) or cytochrome P450 oxidases are responsible for the conversion of hydrophobic PAHs into hydrophilic derivatives by the ring hydroxylation. The ring hydroxylation is the first step of PAHs degradation and also one of the rate-limiting steps. Here, we review the distribution, substrate specificity, and substrate recognition mechanisms of RHOs, along with some techniques and methods used for the research of RHOs and PAHs.

EFFECT OF DIETARY HEME-IRON INTAKES ON THE PREVENTION OF IRON-DEFICIENCY ANEMIA / 体力科学

Purpose : This study was undertaken to clarify the effect of heme-iron supplementation on the prevention of iron-deficiency anemia in male collegiate distance runners.Methods : Forty-one male collegiate runners were divided into three groups, consisting of a heme-iron group (HI), a citrate-iron group (CI), and a non-iron group (NI). Iron tablets (heme-iron or citrate-iron) were administered at a dose of 7 mg per day for two months. The blood components and nutritional intakes were estimated before and after the intervention.Results : The nutritional intakes did not differ among the three groups. The red blood cell, hemoglobin, hematocrit, ferritin, Glutamic-Pyruvate Transferase and <i>γ</i>-Glutamyl Transpeptidase levels were unchanged throughout the experimental periods. After the intervention, the serum iron levels significantly decreased in the NI group but not in the iron-supplemented groups, while the reticulocytes counts increased among the three groups.Conclusion : The small amount of heme-iron supplementation was thus found to have a preventive effect on iron deficiency anemia without causing any negative side affects.

Non-Heme iron availability from Siriraj Hospital diets.

Absorption of nonheme iron has been studied extensively by the use of extrinsic tag radio-labeled iron to meals. Nevertheless, this method is unsuitable for screening large number of meals. The purpose of this study is to determine and compare iron availability from various kinds of meals in laboratory conditions that mimic the human stomach. Three hundred and seventy two common meals from the Siriraj Hospital kitchen were tested. The results of iron availability tests on the 372 Siriraj meals were classified as having low (5.77+2.42%), intermediate (12.42+1.55%), high (17.7+1.44%) and very high (25.8+3.65%) iron availability. Only meals of high and very high iron availability (22.1+4.99%) provided sufficient amounts of iron for the special requirement of teenagers and woman of childbearing age (2.22 to 3.24 mg of Fe per day) while meals of low and intermediate iron availability (8.12+3.84%) provided only 1.02 mg of iron per day. An average amount of estimated iron availability from the 372 meals was 14.12+8.2% of 1.77 mg per day. This was slightly inadequate because 2.06 to 2.15 mg were required per day for the high-risk groups. Results of this study indicated that 42.7% of Siriraj meals adequately provided the physiologic requirement of the high-risk segments of the population, but 57.3% of the meals did not. Improvement of food choices to increase dietary iron intake can be accomplished by including meat, fish or poultry and a source of vitamin C in every meal.

A Study of Iron Status and Anemia in Female High School Students in Ulsan / 대한지역사회영양학회지

This study was designed to assess the iron nutritional status and anemia of high school students. 383 female subjects in Ulsan Metropolitan city were evaluated using a questionnaire, and a measurement of hematological indices. The average height and weight of the respondents were 161.24+/-4.90 cm and 53.12+/-6.37 kg, repectively. The average BMI(body mass index) was 20.43+/-2.26 which was in the normal ramge. The average hemoglobin(Hb) concentration of the subjects was 13.14+/-0.97g/dl, and the average hematocrit(Hct) level was 40.84+/-17.40%. Transferrin saturation{TS(%)} was 20.86+/-10.32%, and the ferritin by Hct(0.05)' and 'cold hands and feet' significantly(r= -0.109, p<0.05). The level of Mean corpuscular volume(MCV) was negatively correlated with 'feel dizzy when standing up', 'tired out easily', and 'decrease ability to concentrate' significantly(p<0.05). In particular, the level of Fe was negatively correlated with 'shortening of breath when going upstairs' and 'feeling blue' significantly(p<0.01). These results suggest That the prevalence of iron deficiency of female high school students is very high, therefore guidelin......

A Study on Iron Nutritional Status of Girls at Puberty in Kangnung Area / 대한지역사회영양학회지

This study was designed to assess the iron nutritional status of girls at puberty in Kangnung area. The subjects consisted of 161 adolescents in sixth-grade in primary school and first-grade in middle school girls. Anthropometric measurements were taken for body weight, height, percentage of body fat, and circumferences of waist and hip. Nutrient intakes were assessed by modified 24-hour recall method. Food models and other measuring tools were also used. Fasting blood samples were obtained and analyzed for hemoglobin(Hb) concentration, hematocrit(Hct), serum iron(FE) and total iron binding capacity(TIBC). Mean values for Hb, Hct, Fe, TIBC, TS and serum ferritin were 13.6+/-0.9g/dl, 39.6+/-3.9%, 91.3+/-36.3 microgram/dl, 327.9+/-45.2 microgram/dl, 28.3+/-11.8% and 37.4+/-24.2ng/ml, respectively. Prevalence of iron deficiency greatly varied by indices from 4.8% when judged by Hb to 18.4% by serum Fe concentration. The Hb concentration was positively correlated with Hct(r=0.641), serum iron(r=0.266) and transferrin saturation(r=0.237)(p<0.05). On the other hand, serum ferritin concentration showed significantly negative correlation with TIBC(r=-0.572). Mean daily intake of iron was 14.94mg and heme iron intake was 1.13mg and which was 7.6% of total iron intake. Total absorbable iron calculated by the method of Mosen was 1.38mg and bioavailability of diectary iron was 9.3%. These results suggest that the prevalence of iron deficiency of pubertal girls is very high, therefore the guidelines for diet and social supports, such as, school food service system should be provided to improve their iron status in middle school students.

Assessment of the Intake and Availability of Dietary Iron and Nutrition Knowledge in Pregnant Women / 대한지역사회영양학회지

This study was designed to estimate mean daily iron intake and its bioavailability and to assess nutrition knowledge for 144 pregnant women in the last trimester. Serum ferritin concentration was analyzed to estimate their iron stores. Dietary intakes of iron(heme iron and nonheme iron), the amounts of MPF(meat, poultry and fish) and ascorbic acid were assessed by modified 24-hr recall method. The food frequency questionnaire was used to assess subjects usual food consumption patterns. The mean value of serum ferritin was 21.3+/-15.3ng/ml and 26.4% of the pregnant women had a serum ferritin level<12ng/ml(i.e. depleted iron stores). The mean daily intake of total orin in the pregnant women was 56.5%(17.0 mg) of RDA and heme iron intake was 0.94 mg which was 5.5% of total iron intake. Total absorbable iron calculated by the method of Monsen was 2.41 mg and bioavailability of dietary iron was 2.41%. Food frequency test score of meats group was positively correlated(r=0.443) with the bioaavailability of dietary iron. The mean score on the nutrition knowledge test of subjects was 12.76(out of a possible 20 points). These results indicate that the nutritional iron status may be improved by increasing either the amount of iron in the diet or its availability.

Iron Nutritional Status of Female Students in Kangnung National University / 대한지역사회영양학회지

To evaluate iron nutritional status of female college students, fasting blood samples were taken from 76 female students of Kangnung National University. Hemoglobin(Hb), hematocrit(Hct), serum iron(Fe), total iron binding capacity(TIBC) and serum ferritin concentrations were measured and transferrin saturation was calculated. Mean values for Hb, Hct, Fe, TIBC, TS and serum freeitin were 13.64+/-1.42g/dl, 40.99+/-4.31%, 103.0+/-33.3 microgram/dl, 395.3+/-9.07 microgram/dl, 26.58+/-9.07%and 26.76+/-17.5ng/ml, respectively. Prevalence of iron deficiency greatly varied by indices from 6.8% when judged by Hct to 26.0% by serum ferritin concentration. The Hb concentration was positively correlated with hematocrit (r=0.5402), serum iron(r=0.2819) and transferrin saturation(r=0.2777)(p<0.05). on the other hand, serum ferritin concentration showed significantly negative correlation with TIBC(r=-0.3196). Two-day dietary intake records were collected from subjects to estimate mean daily iron intake and bioavailability of dietary iron. Mean daily intake of iron was 13.15 mg and heme iron intake was 0.83 mg which was 6.4% of total iron intake. Total absorbable iron calculated by the method of Monsen was 1.27 mg and bioavailability of dietary iron was 9.6%. In the light of high prevalence of iron deficiency based of serum ferritin concentration and low bioavailability of iron in the diet, guidelines about diet should be made to increase the content and bioavailability of iron in the diet if female college students.

A COMPREHENSIVE STUDY ABOUT THE INFLUENCE OF SOYBEAN ON BIOAVAILABILITY OF NON-HEME IRON IN DIET / 营养学报

A series of research results on the influence of soybean to the bioavai?lability of non-heme iron in diet are reported. It is proved that Soybean and some of its products decrease the bioavailability of non-heme iron in diet by human observation and animal experiments. This result is due to insufficient control over the inhibitors and utilization of the enhancers of the bioavailability of iron in soybean itself.Experiments show that through some special treatment processes such as sprouting, fermenting and making bean curd, the above disadvantages may be effectively reduced and remarkably increase the bioavailability of the non-heme iron. These conclusions possess both theoretical and practical meaning for full utilization of soybean protein and effective prevention of iron deficiency anemia.

STUDIES ON THE INTERACTION OF ORGANIC ZINC AND HEME IRON IN RATS / 营养学报

Forty male weanling rats ( Sprague Dawley strain) were chosen and allotted randomly into four treatments. Diets with various organic zinc and heme iron levels were fed for 35 days respectively. GroupⅠ: the basic diet of low zinc and iron. Group Ⅱ: adding the enokitake zinc to the basic diet in which the organic zinc content was 60 ppm. Group Ⅲ: adding the heme iron to the basic diet in which the heme iron content was 24 ppm. Group Ⅳ: adding the enokitake zinc and heme iron to the basic diet in which the organic zinc and heme iron were 60 ppm, 24ppm respectively. At the end, Hb and the content of serum and hepatic iron in the group Ⅲ, Ⅳ were higher significantly than that in the group Ⅰ, Ⅱ.The body weight, serum zinc, hepatic zinc and femur zinc in group Ⅱ, Ⅳ were higher significantly than that in group Ⅰ,Ⅲ. It suggests that there isn't competitive inhibitory interaction between the organic zinc and the heme iron and combined supplementation of them can prevent from zinc and iron deficiency.

A STUDY ON THE BIOAVAILABILITY OF HEME IRON IN RAT / 营养学报

In the present work, the bioavailability of heme iron has been studied by means of the hemoglobin regeneration method with iron-deficient rats model, which was conducted by feeding a low iron basal diet. Anemic rats were then divided into groups to which basal diets with various iron levels (7, 14, 28 ppm Fe) from heme iron (Group 1,2,3) and ferrous sulfate (Group 4, 5, 6, as a reference standard) were subsequently fed respectively.After 5-week regeneration period, the regenerated hemoglobin levels of the rats of corresponding groups were (1) 9.56→12.25, (2) 9.71→12.02, (3)9.51→ 11.09, (4) 9.74→10.81, (5) 9.66→11.24, and (6) 9.67→12.05, thereby the percentage of relative bioavailability (RBA) of heme iron were 117.7%, 124.8%, and 94.9% respectively. This result showed that the lower level of heme iron has a higher RBA. The reason why the effect of high level of heme iron was relatively lower was not fully understood.