Influence of prenatal iron and zinc supplements on supplemental iron absorption, red blood cell iron incorporation, and iron status in pregnant Peruvian women

BACKGROUND: It is estimated that 60% of pregnant women worldwide are anemic. OBJECTIVE: We aimed to examine the influence of iron status on iron absorption during pregnancy by measuring supplemental iron absorption, red blood cell iron incorporation, and iron status in pregnant women. DESIGN: Subjects were 45 pregnant Peruvian women (33+/-1 wk gestation), of whom 28 received daily prenatal supplements containing 60 mg Fe and 250 microg folate without (Fe group, n = 14) or with (Fe+Zn group, n = 14) 15 mg Zn, which were were consumed from week 10 to 24 of gestation until delivery. The remaining 17 women (control) received no prenatal supplementation. Iron status indicators and isotopes were measured in maternal blood collected 2 wk postdosing with oral (57Fe) and intravenous (58Fe) stable iron isotopes. RESULTS: Maternal serum ferritin and folate concentrations were significantly influenced by supplementation (P < 0.05). Serum iron was also significantly higher in the Fe than in the Fe+Zn (P < 0.03) or control (P < 0.001) groups. However, the supplemented groups had significantly lower serum zinc concentrations than the control group (8.4+/-2.3 and 10.9+/-1.8 micromol/L, respectively, P < 0.01). Although percentage iron absorption was inversely related to maternal serum ferritin concentrations (P = 0.036), this effect was limited and percentage iron absorption did not differ significantly between groups. CONCLUSIONS: Because absorption of nonheme iron was not substantially greater in pregnant women with depleted iron reserves, prenatal iron supplementation is important for meeting iron requirements during pregnancy.     

Multiple micronutrient supplements during pregnancy do not reduce anemia or improve iron status compared to iron-only supplements in Semirural Mexico

The impact of iron-only supplements (FE) versus multiple micronutrient supplements containing iron (MM) during pregnancy on iron status was assessed in a subsample (n = 453) of women who participated in a randomized double-blind trial in Mexico. Compliance, monitored by observation, was high (>85%). The two groups were similar at recruitment (<13 wk gestation) for various sociodemographic characteristics and for mean hemoglobin (Hb) concentrations and prevalence of anemia (Hb < 110 g/L; 11%). However, mean serum ferritin was higher (P < 0.05) in the MM group (n = 142) compared to the FE group (n = 148) and the prevalence of iron deficiency (serum ferritin < 12 micro g/L) was lower in the MM group (44.4%) compared to the FE group (57.4%). By the third trimester, almost half the women were anemic in both groups, and mean Hb (g/L) was lower for the MM group (104.2; 95% CI: 102.5, 106.0) compared to the FE group (108.1; 95% CI: 106.4, 109.8) after adjusting for baseline serum ferritin. In contrast, there were no differences in Hb concentrations at 1 mo postpartum or in mean ferritin and prevalence of iron deficiency at 32 wk gestation and 1 mo postpartum (90.9 and 45.1% for the MM group; 92.6 and 47.3% for the FE group, respectively). In conclusion, rather than improve Hb or iron status relative to FE-only supplements as hypothesized, MM supplements may have slightly reduced Hb concentrations during pregnancy. Neither supplement was able to meet iron needs as evidenced by dramatic increases in anemia and iron deficiency by the end of pregnancy.     

Maternal iron status influences iron transfer to the fetus during the third trimester of pregnancy

BACKGROUND: The effect of maternal iron status on fetal iron deposition is uncertain. OBJECTIVE: We used a unique stable-isotope technique to assess iron transfer to the fetus in relation to maternal iron status. DESIGN: The study group comprised 41 Peruvian women. Of these women, 26 received daily prenatal supplements containing iron and folate (n = 11; Fe group) or iron, folate, and zinc (n = 15; Fe+Zn group) from week 10-24 of pregnancy to 1 mo postpartum. The remaining 15 women (control group) received iron supplementation only during the final month of pregnancy. During the third trimester of pregnancy (+/- SD: 32.9 +/- 1.4 wk gestation) oral 57Fe (10 mg) and intravenous 58Fe (0.6 mg) stable iron isotopes were administered to the women, and isotope enrichment and iron-status indicators were measured in cord blood at delivery. RESULTS: The net amount of 57Fe in the neonates' circulation (from maternal oral dosing) was significantly related to maternal iron absorption (P < 0.005) and inversely related to maternal iron status during the third trimester of pregnancy: serum ferritin (P < 0.0001), serum folate (P < 0.005), and serum transferrin receptors (P < 0.02). Significantly more 57Fe was transferred to the neonates in non-iron-supplemented women: 0.112 +/- 0.031 compared with 0.078 +/- 0.042 mg in the control group (n = 15) and the Fe and Fe+Zn groups (n = 24), respectively (P < 0.01). In contrast, 58Fe tracer in the neonates' circulation was not significantly related to maternal iron status. CONCLUSION: The transfer of dietary iron to the fetus is regulated in response to maternal iron status at the level of the gut.     

Adaptation in iron absorption: iron supplementation reduces nonheme-iron but not heme-iron absorption from food

BACKGROUND: Results of cross-sectional studies suggest that in healthy people, iron absorption adapts to meet physiologic needs and stabilize iron stores, but this has not been adequately tested in longitudinal studies. OBJECTIVE: We tested whether heme- and nonheme-iron absorption decrease in response to increased iron intake and whether iron stores reach a steady state. DESIGN: In a randomized, placebo-controlled trial, heme- and nonheme-iron absorption by healthy men and women (n = 57) were measured before and after 12 wk of supplementation with 50 mg Fe/d as ferrous sulfate. Serum and fecal ferritin were measured during supplementation and for 6 mo thereafter. RESULTS: Initially, both heme- and nonheme-iron absorption were inversely associated with serum ferritin concentration. Volunteers who took iron supplements, even those with serum ferritin <21 microg/L (n = 5), adapted to absorb less nonheme iron (3.2% at week 12 compared with 5.0% at week 0, P: < 0.001) but not less heme iron from a beef-based meal. Serum ferritin concentration was slightly but significantly higher after iron supplementation than after placebo (difference = 13 microg/L). This higher ferritin concentration persisted for >/=6 mo after supplementation, except in subjects with low iron stores, whose serum ferritin returned to baseline within 3 mo. Fecal ferritin excretion increased 2.5-fold (P: < 0.05) during supplementation. CONCLUSIONS: Healthy individuals, even those with low iron stores, had reduced nonheme-iron absorption from food in response to iron supplementation. Despite this partial adaptation, iron stores were greater after iron supplementation than after placebo and this difference was sustained, except in individuals with the lowest iron stores.     

Efficacy and tolerability of low-dose iron supplements during pregnancy: a randomized controlled trial

BACKGROUND: Iron deficiency anemia (IDA) is common in pregnant women, but previous trials aimed at preventing IDA used high-dose iron supplements that are known to cause gastrointestinal side effects. OBJECTIVE: The objective was to assess the effect on maternal IDA and iron deficiency (ID, without anemia) of supplementing pregnant women with a low dosage (20 mg/d) of iron. Effects on iron status were assessed at the time of delivery and at 6 mo postpartum. Gastrointestinal side effects were assessed at 24 and 36 wk of gestation. DESIGN: This was a randomized, double-blind, placebo-controlled trial of a 20-mg daily iron supplement (ferrous sulfate) given from 20 wk of gestation until delivery. RESULTS: A total of 430 women were enrolled, and 386 (89.7%) completed the follow-up to 6 mo postpartum. At delivery, fewer women from the iron-supplemented group than from the placebo group had IDA [6/198, or 3%, compared with 20/185, or 11%; relative risk (RR): 0.28; 95% CI: 0.12, 0.68; P < 0.005], and fewer women from the iron-supplemented group had ID (65/186, or 35%, compared with 102/176, or 58%; RR: 0.60; 95% CI: 0.48, 0.76; P < 0.001). There was no significant difference in gastrointestinal side effects between groups. At 6 mo postpartum, fewer women from the iron-supplemented group had ID (31/190, or 16%, compared with 51/177, or 29%; RR: 0.57; 95% CI: 0.38, 0.84; P < 0.005). The rate of IDA between the groups did not differ significantly at 6 mo postpartum. CONCLUSION: Supplementing the diet of women with 20 mg Fe/d from week 20 of pregnancy until delivery is an effective strategy for preventing IDA and ID without side effects.     

Iron status of women is associated with the iron concentration of potable groundwater in rural Bangladesh

Women of reproductive age are at a high risk of iron deficiency, often as a result of diets low in bioavailable iron. In some settings, the iron content of domestic groundwater sources is high, yet its contribution to iron intake and status has not been examined. In a rural Bangladeshi population of women deficient in dietary iron, we evaluated the association between groundwater iron intake and iron status. In 2008, participants (n = 209 with complete data) were visited to collect data on 7-d food frequency, 7-d morbidity history, 24-h drinking water intake, and rice preparation, and to measure the groundwater iron concentration. Blood was collected to assess iron and infection status. Plasma ferritin (μg/L) and body iron (mg/kg) concentrations were [median (IQR)] 67 (46, 99) and 10.4 ± 2.6, respectively, and the prevalence of iron deficiency (ferritin < 12 μg/L) was 0%. Daily iron intake from water [42 mg (18, 71)] was positively correlated with plasma ferritin (r = 0.36) and total body iron (r = 0.35) (P < 0.001 for both). In adjusted linear regression analyses, plasma ferritin increased by 6.1% (95% CI: 3.8, 8.4%) and body iron by 0.3 mg/kg (0.2, 0.4) for every 10-mg increase in iron intake from water (P < 0.001). In this rural area of northern Bangladesh, women of reproductive age had no iron deficiency likely attributable to iron consumed from drinking groundwater, which contributed substantially to dietary intake. These findings suggest that iron intake from water should be included in dietary assessments in such settings.     

Iron status and dietary intake of Chinese pregnant women with anaemia in the third trimester

Anaemia in pregnancy is a major public health problem in China. Anaemia in pregnant women may be related to dietary intake of nutrients. To examine the relationship between iron status and dietary nutrients, a cross-sectional study in pregnant women was carried out. The intake of foods and food ingredients were surveyed by using 24-h dietary recall. Blood haemoglobin, haematocrit, serum iron, serum ferritin, transferrin and soluble transferrin receptor were measured in 1189 clinically normal pregnant women in the third trimester of pregnancy. The results showed that the average daily intake of rice and wheat was 504.2 g in the anaemia group and 468.6 g in the normal group. Carbohydrates accounted for 63.69% and 63.09% of energy in the anaemia and normal groups, respectively. Intake of fat was very low; 18.38% of energy in anaemia group and 19.23% of energy in normal group. Soybean intake was 109.4 g/day and 63.6 g/day in the anaemia and normal groups, respectively (P < 0.001). There were lower intakes of green vegetables (172.1 g/day) and fruits (154.9 g/day) in the anaemia group than in the normal group (246.2 g/day green vegetables (P < 0.001) and 196.4 g/day fruit (P < 0.001)). Intakes of retinol and ascorbic acid were much lower in the anaemia than in the normal group (P < 0.001). In the anaemia group, vitamin A intake was only 54.76% of the Chinese recommended daily allowance (RDA) and ascorbic acid intake was 53.35% of the Chinese RDA. Intake of total vitamin E was 14.55 mg/day in the anaemia group compared with 17.35 mg/day in the normal group (P < 0.016). Moreover, intake of iron in pregnant women with anaemia was slightly lower than that in the normal group. Comparison of iron status between the anaemia and normal groups found serum iron in women with anaemia at 0.89 microg/L, which was significantly lower than 1.09 microg/L in the normal group (P < 0.001). There were lower average values of ferritin (14.70) microg/L) and transferrin (3.34 g/L) in the anaemia group than in the normal group (20.40 microg/L ferritin (P < 0.001) and 3.44 g/L transferrin (P < 0.001)). Soluble transferrin receptor was significantly higher (32.90 nmol/L) in the anaemia than in the normal group (23.58 nmol/L; P < 0.001). The results of this study indicate that anaemia might be attributed to a low iron intake, a low intake of enhancers of iron absorption and a high intake of inhibitors of iron absorption from a traditional Chinese diet rich in grains.     

Dietary iron intake is positively associated with hemoglobin concentration during infancy but not during the second year of life

Iron status during infancy and early childhood reflects highly dynamic processes, which are affected by both internal and external factors. The regulation of iron metabolism seems to be subjected to developmental changes during infancy, although the exact nature of these changes and their implications are not fully understood. We wanted to explore the association between dietary iron intake and indicators of iron status, and to assess temporal changes in these variables. This was done by secondary analysis of data from a recently conducted dietary intervention trial in which healthy, term, well-nourished infants were randomly assigned to consume iron-fortified infant cereals with regular or low phytate content, or iron-fortified infant formula. Dietary iron intake from 6 to 8 mo and from 9 to 11 mo was associated with hemoglobin (Hb) concentration at 9 mo (r = 0.27, P < 0.001) and 12 mo (r = 0.21, P = 0.001), respectively, but iron intake from 12 to 18 mo was not associated with Hb at 18 mo. In contrast, iron intake from 6 to 11 mo was not associated with serum ferritin (S-Ft) at 9 or 12 mo, whereas iron intake from 12 to 17 mo was positively associated with S-Ft at 18 mo (r = 0.14, P = 0.032). These shifts in associations between dietary iron intake, and Hb and S-Ft, respectively, may be due to developmental changes in the channeling of dietary iron to erythropoiesis relative to storage, in the absence of iron deficiency anemia. These observations should be taken into consideration when evaluating iron nutritional status during infancy and early childhood.     

The association of time in the US and diet during pregnancy in low-income women of Mexican descent

This study compared nutritional intake during pregnancy among women of Mexican descent according to country of birth (US vs. Mexico) and, for Mexico-born women, according to number of years lived in the US (or= 11 years). A 72-item food frequency questionnaire (FFQ) was used to assess dietary intake in 474 pregnant Mexico-born immigrants and US-born Mexican-Americans. Mexico-born women had significantly higher intakes of calories (P = 0.02), fibre (P < 0.001), vitamin A (P < 0.001), vitamin C (P = 0.03), vitamin E (P < 0.01), folate (P < 0.01), calcium (P < 0.001) and zinc (P = 0.02) from their diets than US-born women. Intakes of all nutrients except vitamin C and zinc remained significantly higher in Mexico-born women when nutrients from both diet and vitamin supplements were considered. Among Mexico-born women, increasing years of residence in the US was associated with lower intake of calories (P(trend) < 0.01), fibre (P(trend) < 0.01), folate (P(trend) = 0.03), iron (P(trend) = 0.05) and zinc (P(trend) = 0.03), although only the trend for iron remained significant when vitamin supplement sources were included. A large percentage of women had inadequate intake of vitamin E (58%), folate (61%), iron (77%) and zinc (47%) from their diets during pregnancy and these rates were higher in US-born women than Mexico-born women.     

Postnatal iron status of Hong Kong Chinese women in a longitudinal study of maternal nutrition.

OBJECTIVE: To report postnatal iron nutritional status of Hong Kong Chinese women during the first 6 months postpartum. DESIGN AND SUBJECTS: A longitudinal study examining postnatal calcium and iron status of Hong Kong Chinese breastfeeding and formula-feeding women was conducted during 1998. Postpartum women aged 20-40 y, with no bone or blood disorders were recruited and interviewed at 0 (baseline), 2, 6 weeks, 3 and 6 months postpartum. Dietary intake was assessed by a 3 day dietary record and cross checked by a 24 h recall. Complete blood count and serum ferritin level were measured to assess anaemia and iron status. In this report, subjects were divided into an anaemic group (haemoglobin level < 10 g/dl) and a non-anaemic group (haemoglobin level > or = 10 g/dl) according to baseline haemoglobin levels. RESULTS: At baseline, 13/47 (27.7%) subjects were anaemic. Two of these 13 anaemic subjects were still anaemic at 3 and 6 months postpartum. Anaemic subjects showed significantly (P < 0.01) greater amounts of blood loss and a higher rate of primary postpartum haemorrhage than the non-anaemic subjects. Daily food intake and dietary nutrient intake did not differ significantly between the two groups. During the first 6 weeks postpartum, subjects in both groups consumed more poultry and egg, and comparable amounts of meat, compared with women in the Hong Kong general population. Iron and vitamin C intakes for the majority of subjects reached 60% of the US Recommended Daily Allowances. Regression analysis suggested that the rate of change in haemoglobin level in the first 6 weeks postpartum was positively correlated with baseline MCV level and serum ferritin level, but negatively correlated with baseline haemoglobin level. CONCLUSIONS: Blood loss at delivery is an important factor for postpartum anaemia. Postnatal recovery of iron status of this group of women appeared to be more related to physiological factors than to dietary factors. The role of diet as well as other physiological changes in postpartum women requires further investigation. Finding ways to minimise blood loss at delivery could be the most practical strategy to reduce the rate of postpartum anaemia. SPONSORSHIP: CSM was supported by a research studentship from the Research Grants Council, Hong Kong.     

Validity of the Willett food frequency questionnaire in assessing the iron intake of French-Canadian pregnant women

ObjectiveMaternal intake is crucial to pregnancy outcomes. Evidence shows that both nutrient deficiency and excess can have adverse effects. In pregnancy, changes in iron metabolism occur; therefore, dietary reference intakes increase to support expansion of red cells and maternal–fetal transfer of iron. Appropriate and valid assessment tools are required to investigate nutritional concerns in mothers with and without gestational diabetes mellitus (GDM). The objective of this study was to assess the Willett food frequency questionnaire (FFQ) to assess iron intake in women with (n = 15) and without (n = 45) GDM.MethodsTo validate the modified FFQ, estimated total iron intake during the third trimester was compared with biomarkers of iron status such as serum ferritin, soluble transferrin receptor (sTfR), and the sTfR:F index at delivery. Data were tested for normality using the D’Agostino-Pearson test. Differences between groups were tested using t tests or Mann–Whitney tests. Correlations were tested using Spearman’s ρ. Significance was set at P < 0.05.ResultsSignificant crude and energy-adjusted serum ferritin and total iron intake were related (ρ = 0.30; P < 0.05) in women without GDM. Serum ferritin, sTfR, and the sTfR:F index were different (P < 0.05) between women with intakes above and below the recommended levels. Cross-classification showed agreement between methods in mothers with and without GDM; on average, 63% of the women were classified into the same or adjacent quartile when ranked by FFQ and iron status.ConclusionThese findings suggest the Willett FFQ is a good tool for assessing total iron intake of French-Canadian pregnant women.     

Dietary patterns among postpartum women treated at a municipal health center in Rio de Janeiro, Brazil

This study aimed to longitudinally compare nutrient and food intakes by 276 lactating women. Dietary intake was collected using a food frequency questionnaire. Data analysis used the Student-t and ANOVA tests, comparing quantitative and qualitative dietary variation from pregnancy to postpartum. Mean daily energy intake was 2,889 kcal for pregnant and 2,081 kcal for lactating women. Macronutrient dietary distributions were within internationally recommended standards. Compared to pregnancy, there was a decrease in most nutrients and foods ingested during postpartum. Dietary changes increased the density of proteins, fat, iron, rice, beans, chicken, and beef (p < 0.02) and decreased the density of carbohydrate, cereals, fruits, and milk and dairy products (p < 0.001). The results indicate a need for dietary guidelines for women, particularly during the postpartum period.     

Response of hemoglobin, serum ferritin, and serum transferrin receptor during iron supplementation in pregnancy: a prospective study

OBJECTIVE: We evaluated the effect of iron supplementation on biochemical indicators of iron status, namely hemoglobin (Hb), serum ferritin (SF), and serum transferrin receptor (sTfR), during pregnancy. METHODS: A prospective study was conducted in 73 pregnant women who received daily supplements of 60 mg of iron and 500 microg of folic acid for 100 d from 19 wk of gestation. The indicators of iron status (Hb, SF, and sTfR) at 19, 27, and 35 wk of gestation were analyzed. The response of iron status indicators to iron supplementation was assessed in the cohort and in pregnant women who were anemic (n = 35) and non-anemic (n = 38) at 19 wk. RESULTS: All three indicators of iron status during supplementation (27 and 35 wk) were similar to the presupplementation status. The sTfR as an indicator correlated negatively with presupplementation Hb levels (r = -0.417). Based on sTfR level in iron-adequate pregnant women, a cutoff value of at least 12.0 mg/L was derived to define iron deficiency in pregnancy. When the response was tested in anemic pregnant women, iron supplementation improved mean Hb (P < 0.05) at the end of 35 wk (96 +/- 8.8 to 110 +/- 20.2 g/L) of gestation, with no change in SF. Conversely, non-anemic pregnant women showed a significant increase in SF and a decrease in Hb (122 +/- 11.6 to 112 +/- 15.2 g/L) at 35 wk of gestation. A significant effect of iron intake on sTfR was seen only among iron-deficient anemic women. CONCLUSIONS: These observations suggest that, during pregnancy, sTfR responds to iron supplementation when there is iron-deficiency anemia and therefore can be used as an indicator.     

Iron absorption in breast-fed infants: effects of age,iron status,iron supplements,and complementary foods

BACKGROUND: Iron supplements are often recommended for older breast-fed infants, but little is known about factors affecting iron absorption from human milk or supplements. OBJECTIVE: We investigated the effects of age, iron status, and iron intake on iron absorption in healthy, term, breast-fed infants. DESIGN: Twenty-five infants were randomly assigned to receive either 1) iron supplements (1 mg x kg(-1) x d(-1)) from 4 to 9 mo of age, 2) placebo from 4 to 6 mo and iron supplements from 6 to 9 mo, or 3) placebo from 4 to 9 mo. Infants were exclusively breast-fed to 6 mo and partially breast-fed to 9 mo of age. Iron absorption was assessed by giving (58)Fe with mother's milk at 6 and 9 mo. Blood samples were obtained at 4, 6, and 9 mo, and complementary food intake was recorded at 9 mo. RESULTS: At 6 mo, mean (+/-SD) fractional iron absorption from human milk was relatively low (16.4 +/- 11.4%), with no significant difference between iron-supplemented and unsupplemented infants. At 9 mo, iron absorption from human milk remained low in iron-supplemented infants (16.9 +/- 9.3%) but was higher (P = 0.01) in unsupplemented infants (36.7 +/- 18.9%). Unexpectedly, iron absorption at 9 mo was not correlated with iron status but was significantly correlated with intake of dietary iron, including supplemental iron. CONCLUSIONS: Changes in the regulation of iron absorption between 6 and 9 mo enhance the infant's ability to adapt to a low-iron diet and provide a mechanism by which some, but not all, infants avoid iron deficiency despite low iron intakes in late infancy.     

Adequate Dietary Intake and Vitamin D Supplementation: A Study of Their Relative Importance in Determining Serum Vitamin D and Ferritin Concentrations during Pregnancy

Vitamin D is essential for human health. However, it is not clear if vitamin D supplementation is necessary for all pregnant women. This study examines the relative importance of dietary patterns and vitamin D supplementation frequency in determining serum 25-hydroxyvitamin D (25(OH)D) and ferritin concentrations among pregnant women in Hong Kong, China. A total of 572 healthy women were recruited from antenatal clinics at 25–35 weeks pregnant. Participants completed an electronic version of the food frequency questionnaire and a web questionnaire on supplement use. Their blood samples were tested for serum 25(OH)D and ferritin. The associations of dietary patterns and vitamin D supplementation frequency with serum 25(OH)D and ferritin concentrations were analyzed using moderated hierarchical regression. Two dietary patterns were identified. The adequate dietary intake was characterized by the high probability of meeting recommended daily food group servings, whereas the inadequate dietary intake was characterized by inadequate consumption of vegetables, fruits, meat, fish, and eggs, or alternatives. The association between adequate dietary intake and serum ferritin concentrations was independent of vitamin D supplementation frequency (β = 0.05, p = 0.035), but dietary patterns interacted with vitamin D supplementation frequency to determine serum 25(OH)D concentrations (β = −13.22, p = 0.014). The current study presents evidence on the relative importance of dietary patterns and vitamin D supplementation in maintaining sufficient vitamin D and iron in pregnancy. Antenatal nutrition counselling services should be provided to pregnant women who show signs of inadequate dietary intake.     

Iron status of pregnant Indian women from an area of active iron supplementation

ObjectiveThe aim of this study was to investigate the iron status of pregnant tribal women from Ramtek, Nagpur, Maharashtra, India using a combination of indices.MethodsA community-based observational study was conducted to assess iron status using a convenience sample of pregnant Indian tribal women from Ramtek. Pregnant women were recruited at 13 to 22 wk gestation (first visit; n = 211) and followed to 29 to 42 wk gestation (second visit; n = 177) of pregnancy. Sociodemographic and anthropometric data; iron supplement intake; and blood samples for estimating hemoglobin (Hb), serum ferritin (SF), soluble transferrin receptor (sTfR), and C-reactive protein (CRP) were obtained.ResultsThe mean (SD) Hb concentration at recruitment was 106 (15) g/L and 106 (14) g/L at the second visit; 41% of the women at recruitment and 55% at second visit were anemic (14% higher, P < 0.001). No women at recruitment and 3.7% at second visit had SF concentration < 15 ng/mL; and 3.3% at recruitment and 3.9% at the second visit had sTfR > 4.4 ng/mL (0.6% higher, P = 0.179). Almost 62% and 71% of pregnant women used iron supplements at both visits, respectively. Iron supplement intake > 7 d in the preceding month improved the Hb concentration by 3.23 g/L and reduced sTfR concentration by 13%; women who were breastfeeding at the time of recruitment had 11% higher SF concentration.ConclusionsThe iron indices suggest that pregnant tribal women of central India, although anemic, had good iron status. Use of iron supplements > 7 d in the preceding month improved iron status; however, non–iron-deficiency anemia persisted in this group.     

Dietary intake and iron status of Australian vegetarian women.

BACKGROUND: Despite the possible overall health benefits of a vegetarian diet, there is concern that some vegetarians and infrequent meat eaters, particularly females, may have inadequate iron status because of low or no heme-iron intakes. OBJECTIVE: The objective was to investigate the nutritional intake and iron status of vegetarian women. DESIGN: The nutritional intakes of 50 free-living vegetarian women aged 18-45 y and 24 age-matched omnivorous control women were assessed by using 12-d weighed dietary records. Iron status was assessed by measuring hemoglobin and serum ferritin concentrations. RESULTS: There was no significant difference between mean (+/-SD) daily iron intakes of vegetarians and omnivores (10.7 +/- 4.4 and 9.9 +/- 2.9 mg, respectively), although heme-iron intakes were low in the vegetarians. Vegetarians had significantly lower intakes of protein (P < 0.01), saturated fat (P < 0.01), and cholesterol (P < 0.001), and significantly higher intakes of dietary fiber (P < 0.001) and vitamin C (P < 0.05). Mean serum ferritin concentrations were significantly lower (P = 0.025) in vegetarians (25.0 +/- 16.2 microg/L) than in omnivores (45.5 +/- 42.5 microg/L). However, similar numbers of vegetarians (18%) and omnivores (13%) had serum ferritin concentrations <12 microg/L, which is a value often used as an indicator of low iron stores. Hemoglobin concentrations were not significantly different. CONCLUSION: It is important that both vegetarian and omnivorous women maintain an adequate iron status and follow dietary practices that enhance iron absorption.     

A national survey of iron and folate status in pregnant women in Switzerland.

Women often do not meet the increased iron and folate needs of pregnancy. Maternal iron-deficiency anemia is associated with poor maternal and infant outcomes, including preterm delivery and low birth weight. Poor folate status increases risk for maternal anemia, spontaneous abortion, and congenital defects. Because of this, supplemental iron and folate are often recommended during pregnancy. There are few data on iron and folate status in pregnant women in Switzerland. We measured iron and folate status in a national sample of Swiss pregnant women, estimated the prevalence of anemia, and determined if supplement use is associated with iron and/or folate status in this group. A 3-stage probability to size cluster sampling method was used to obtain a representative national sample of pregnant women (n = 381) in the second and third trimester. We measured hemoglobin, hematocrit, mean corpuscular volume, and serum folate and ferritin concentrations. Serum transferrin receptor concentration was determined in anemic subjects. The use of iron and folate supplements was evaluated by questionnaire. Mean hemoglobin (+/- SD) in the sample was 123 g/L (+/- 1.0). The prevalence of anemia was 6%. Of the 21 anemic women, 11 were iron-deficient, giving an iron-deficiency anemia prevalence of 3%. Nineteen percent of women had low serum ferritin concentrations (< 12 micrograms/L) and 4% had low serum folate concentration (< 2.5 micrograms/L). Supplements containing iron were taken by 65% of women, and 63% were taking folate-containing supplements. Women in the second and third trimester taking folate-containing supplements had significantly higher serum folate concentrations compared to those not taking a folate supplement (p < 0.001). In the third trimester, women taking iron-containing supplements had significantly higher serum ferritin concentrations compared to those not taking an iron-containing supplement (p < 0.01). Our findings indicate that iron and folate status appears to be adequate in the majority of pregnant women in Switzerland, and that use of iron and folate supplements may have a positive impact on status.     

补充铁剂对上海育龄妇女缺铁性贫血改善效果研究

目的了解缺铁性贫血育龄妇女补充铁剂的效果,探讨维持育龄妇女正常铁营养状况的总铁摄入量。方法招募贫血的育龄妇女74名,年龄21～45岁,按血红蛋白随机分成干预组和对照组,每日分别口服一包铁营养包(主要成分为焦磷酸铁和富马酸亚铁,含铁元素8mg)和安慰剂,连续服用6个月观察效果。干预前、3个月及6个月后两组均进行缺铁性贫血相关指标检查、膳食频率调查及24 h膳食回顾调查。结果干预6个月后干预组血红蛋白和血清铁蛋白均显著高于对照组(P<0.01),干预组和对照组血红蛋白值达标人数分别为15人(44.1%)和5人(14.3%),P<0.01;血清铁蛋白达标人数分别为11人(35.5%)和4人(12.1%),P<0.05。膳食铁的平均摄入量为14.0mg/d。总铁摄入量(膳食铁加补充的铁)与血红蛋白值的改变呈正相关(r=0.57,P﹤0.01)。膳食纤维摄入多和月经量多则是危险因素(P<0.05)。结论连续6个月每日补充8mg铁能有效改善育龄妇女缺铁性贫血,育龄妇女每日摄入23.2mg铁可维持正常铁储存状况。     

Iron status and pregnancy in a northern Canadian population: relationship to diet and iron supplementation.

To determine the extent of iron deficiency, the prognostic value of prenatal ferritin levels and the desirability of prenatal iron supplementation in the western Canadian arctic, dietary iron intake was determined in 171 women and ferritin levels determined in 121 women during pregnancy, 79 at delivery and 77 postnatally, as well as in 65 of their infants at birth and 74 postnatally. Iron deficiency (ferritin < 15 ng/ml) was present in 34% of women during the first two trimesters, 25% (20/79) at delivery and in 51.7% (15/29) of mothers and 31% (9/29) of infants beyond four months after delivery. Maternal follow-up ferritin levels correlated poorly with dietary iron intake but well with prenatal ferritin levels, which appeared to be good predictors of the effectiveness of supplementation. Mean infant follow-up ferritin levels were 105.6 +/- 115.2 ng/ml with, and 46.7 +/- 63.5 without maternal prenatal supplementation (p = 0.03); maternal, 45.5 +/- 40.9 ng/ml with, and 12.8 +/- 9.2 without (p < 0.001). Measurement of prenatal ferritin levels to determine risk of iron deficiency and routine prenatal iron supplementation are recommended.