Zinc Status

Zinc status and dietary intake of pregnant women,

Alexandria, EgyptNoha E. Naema, Nawal M. El-Sayedb, Samia A. Nossierc

and Azza A. Abu Zeida

aMinistry of Health (MOH), bDepartments of Nutritionand cFamily Health, High Institute of Public Health,Alexandria University, Alexandria, Egypt

Correspondence to Noha E. Naem, PhD, RegionalCenter for Women’s Health (ARC), Ministry of Health(MOH), Ramleh Station Square Abdel Hamid BadawySt. Alexandria Corniche, Alexandria, MD 21653, EgyptTel: + 20 122 402 6459; fax: + 002 03 4832276;e-mails: [email protected],[email protected]

Received 20 January 2014Accepted 23 January 2014

Journal of the Egyptian Public Health

Association 2014, 89:35–41

Background and objectives

Deficiencies of protein, energy, and micronutrients are highly prevalent in developing

countries and have major effects on pregnancy outcome. Low dietary intake is the

most common reason for zinc deficiency. The present research is part of a larger

double-blind randomized-controlled trial to evaluate the effect of zinc supplementation

on the pregnancy outcome. The aim of the present study was to assess the zinc status

and dietary intake of zinc and other macronutrients and micronutrients among pregnant

women in Alexandria, Egypt.

Participants and methods

Participants were pregnant women attending two antenatal care centers that serve

low-income and middle-income pregnant populations. A total of 1055 healthy pregnant

women aged 20–45 years were assessed for eligibility. Of these, only 675 had serum

zinc level below the median for the gestational age. They were assigned randomly

to one of three parallel groups. Zinc supplements were provided from 16 weeks

until delivery. A subsample of 100 women was assessed for their dietary intake.

A questionnaire interview was used to collect basic socioeconomic and data on

current pregnancy and labor. Dietary data were collected using the 24-h recall method

and a food frequency questionnaire. The nutritive value of the daily diet was computed

using the Egyptian food composition tables. The blood hemoglobin level, serum zinc

level, and fasting blood sugar were determined.

Results

Zinc deficiency was detected among 53.5% of the sample. Dietary intake of zinc was

low, representing 59.4, 59.4, and 62% of the recommended dietary allowance (RDA)

for the zinc group, zinc plus multivitamins, and the placebo group, respectively. The

iron intake was below 50% of the RDA. Protein intake was less than 70% of the RDA.

The mean intakes of fat were 191.97, 211.8, and 196.3 g/day for the three groups.

The mean energy intake represented 51.1, 53.5, and 49.8% of the RDA.

Conclusion and recommendations

Except for carbohydrate intake, the dietary intake of all macronutrients and

micronutrients was low. The lowest intake was of iron (below 50% of the RDA).

Zinc and protein intake represented less than 70% of the RDA. The overall energy

intake was around 50% of the RDA. Nutritional health education should be used as a

preventive approach to allow the large sector of the low-income population to maximize

the use of the limited resources in the best way. In women at high risk of zinc

deficiency, zinc supplementation should be added to the routine supplements.

Keywords:

dietary intake, Egypt, micronutrients, pregnancy, zinc

J Egypt Public Health Assoc 89:35–41& 2014 Egyptian Public Health Association0013-2446

IntroductionMaternal undernutrition is a major public health issue in

the developing world, and it is estimated that between 10

and 19% of women are undernourished, with a BMI of less

than 18.5 [1]. In addition, dietary intake studies show that

maternal micronutrient deficiencies in iron, vitamin A, zinc,

vitamin B12, iodine, and folate are widespread and have a

negative impact on pregnancy outcomes, increasing mater-

nal morbidity and mortality [2–4].

Zinc deficiency has long been considered a common but

overlooked problem in developing countries. It is widely

believed that zinc deficiency is as widespread as iron

deficiency, affecting nearly half of the world’s popula-

tion [5]. According to data provided by the Research

Institute of Nutrition (Russian), on average, 77% of

pregnant women have deficiency of vitamins, essential

trace elements, and minerals, and the daily intake includes

no more than 50% of the daily requirement of zinc [6].

Original article 35

0013-2446 & 2014 Egyptian Public Health Association DOI: 10.1097/01.EPX.0000443987.44261.9b

Copyright © Journal of the Egyptian Public Health Association. Unauthorized reproduction of this article is prohibited.

mailto:[email protected]

mailto:[email protected]

Zinc is required for cellular division and differentiation.

In addition to DNA synthesis, zinc regulates gene

expression. Growth-stimulating hormones such as insu-

lin-like growth factors need zinc for their activity. Zinc is

also involved in the regulation of apoptosis-programmed

cell death. Zinc is an essential nutrient for normal

embryogenesis [7].

The consequences of severe human zinc deficiency have

been known since the 1960s, but only more recently

have the effects of milder degree of zinc deficiency been

recognized. Severe maternal zinc deficiency has

been associated with spontaneous abortion and congenital

malformations (i.e. anencephaly), whereas milder forms

of zinc deficiency have been associated with low birth

weight, intrauterine growth retardation, and preterm

delivery. Importantly, milder forms of zinc deficiency

have also been related to complications of labor and

delivery, including prolonged or inefficient first-stage

labor and protracted second-stage labor, premature

rupture of membranes, and the need for assisted or

operative delivery [8].

This study aimed to assess the zinc status and dietary

intake of zinc and other macronutrients and micronu-

trients among pregnant women of low and middle

socioeconomic levels in Alexandria, Egypt.

Study design

This study is part of a larger double-blinded, placebo-

controlled, parallel-group randomized trial conducted in

Alexandria, Egypt, to test the effect of two regimens of

zinc supplementation on the outcome of pregnancy.

Women with a low serum zinc level were eligible for

enrollment in the trial. Screening for zinc deficiency

(n = 1055) was carried out by measuring the level of

serum zinc. Eligible participants (n = 675) were assigned

randomly to one of three parallel groups in a 1 : 1: 1 ratio.

The control group (group 1) received placebo, the zinc

group (group 2) received a daily supplement of 30 mg of

zinc as zinc sulfate, and the zinc plus multivitamins group

(group 3) received 30 mg zinc as zinc sulfate added to

multivitamins.

Eligibility criteria for participants

Women who presented for antenatal care in two antenatal

care centers that serve low-income and middle-income

pregnant population were assessed for eligibility. The

inclusion criteria were as follows: age range between 20

and 45 years, gestational age below 16 weeks assessed by

ultrasonography, BMI between 18 and 26 kg/m2, normal

course of pregnancy, and a serum zinc level below the

estimated median for gestational age at the time of

enrollment [9]. The exclusion criteria were as follows:

women identified through interviews to be on any other

form of zinc supplements at any dosage, women with an

established risk of having reduced or excessive birth

weight of infants (e.g. diabetes, hypertension, renal

and heart disease), old primigravidae, and cases that

developed complications or twin pregnancy during the

follow-up period.

Sampling

The sample size required to enable the detection of a

mean difference of 150 g in birth weight with 80% power,

0.5 SD for each group, 5% level of significance was

estimated to be 534 (178 per each group). The study

included up to 675 cases in the three groups in order to

overcome the dropout. Therefore, after randomization of

cases, there were 223 cases in the control group, 225 cases

in the zinc group, and 227 cases in the combined zinc and

multivitamin group. In all, 199 cases in the placebo group,

198 cases in the zinc group, and 200 cases in the zinc plus

multivitamins group completed the study.

Ethical considerations

Eligible women provided free and informed consent

before enrollment. Women who agreed to participate in

the study signed/thumb-printed the consent form and

those who consented were given copies of the signed

consent form. After enrollment, each participant was

assigned a unique serial number, and this was recorded on

her antenatal care card. The protocol of the study was

approved by the ethical committees of Ministry of Health

(MOH) and the High Institute of Public Health (HIPH).

The trial was registered in the WHO trial registry

(PACTR20130300045309).

Methods of data collectionDetermination of serum zinc

Nonfasting venous blood was obtained during morning

hours using plastic syringes, stainless-steel needles, and

trace mineral-free plastic tubes. Serum was separated at a

maximum of 6 h after collection and stored at – 201C

until analyzed. Zinc concentration was measured using

flame atomic absorption spectrophotometry. Serum zinc

level was measured at enrollment in the study and a

second measurement was performed between 28 and 32

weeks’ gestation.

The reference median serum zinc level at the second

trimester was based on the values obtained from a recent

study on pregnant women attending MCH centers in

Alexandria (75 mg/dl) [9]. Women with serum zinc levels

below the median and who fulfilled the inclusion criteria

for the study were subjected to the following.

A structured interview was administered to mothers

to collect the following data:

(1) Personal and sociodemographic data such as age,

residence, educational level, working status, family

size, income, and housing conditions.

(2) Obstetric data such as gravidity, parity, abortions, and

any obstetric complications in previous pregnancies

or deliveries.

(3) Dietary intake using the 24-h recall method and food

frequency questionnaire, with a focus on intake of

foods that might enhance or inhibit zinc absorption.

This assessment was performed on a subsample of 100

women in the three groups studied. Enhancers of zinc

absorption that were determined were low calcium

36 Journal of the Egyptian Public Health Association


intake represented by low consumption of dairy

products and protein intake. Inhibitors of zinc absorp-

tion were represented by fibers, phytates, and iron.

Routine antenatal examination included the following:

(1) Gestational age determination using the last men-

strual period and ultrasound.

(2) Routine laboratory investigations: urine analysis,

random blood glucose level, and hemoglobin con-

centration using the cyanmethemoglobin method.

Anthropometry of women during pregnancy

The weights of the women were measured to the nearest

0.1 kg on an electronic bathroom weighing scale and

height was measured to the nearest 0.1 cm with a height

stick. BMI was calculated as follows: BMI = weight (kg)/

height (m2).

Management of dietary data

Dietary intake was assessed by a 24-h dietary recall and

separate questions on the use of vitamin or mineral

supplements. Portion sizes were estimated using standard

household measures quantified in grams. Dietary data

intake of the 24-h recall method was analyzed using the

Egyptian food composition tables [10] to determine the

daily intake of macronutrients (protein, fat, carbohy-

drates, and energy) and that of specified micronutrients

(zinc, calcium, iron, and vitamin A). The mean daily

intake was compared with that of the recommended

dietary allowance (RDA) level of the Food and Nutrition

Board, Institute of Medicine (IOM) [11] to determine

the percent adequacy of intake from the specified

nutrient.

Statistical analysis

Data were fed to the computer using the Predictive

Analytics Software (PASW Statistics 18; SPSS Inc.,

Illinois, Chicago, USA). The intention-to-treat strategy

was used for primary analysis, and involved all partici-

pants who were assigned randomly. The association

between categorical variables was tested using the w2-test.

Yate’s exact correction was applied when more than 20% of

the cells had an expected count less than 5. Quantitative

data were described using mean and SD. When there were

at least 30 observations per group, parametric statistics

were used for comparing means in this study irrespective

of the state of normality of the data as the conclusions

drawn by both the t and F distributions will not be seriously

affected. Independent one-way analysis of variance was

used to compare quantitative variables among more than

two groups.

ResultsThe mean age of the participants at recruitment was

27 ± 5.4 years, with a range of 16–44 years. The mean

gestational age at recruitment was 13.0 ± 3.0 completed

weeks. The study groups did not differ significantly in

terms of their baseline characteristics, except for age,

where the iron–zinc group included older participants

[F(1,598) = 4.864, P = 0.028] (data were not shown).

Out of 1115 women, 675 had low serum zinc level

(53.5%). The mean serum zinc values were 60.2 ± 6.46,

58.6 ± 6.87, and 59.2 ± 6.46 mg/dl for the placebo group,

zinc, and zinc plus multivitamins, respectively. There

were statistically significant difference between the three

studied groups in first sample serum zinc (P = 0.025).

Hemoglobin level ranged between 9 and 11.8 g/dl, with a

mean and SD of 10.5 ± 0.63, 10.5 ± 0.64, and

10.3 ± 0.57 g/dl for the three groups, respectively. There

was no statistically significant difference in hemoglobin

level (P = 0.051). About one-third (29.3%) of the total

sample had hemoglobin level below 10 g/dl (Table 1).

Dietary intake

Table 2 shows the intake of macronutrients in the three

groups. The mean protein intake was 48.08, 48.32, and

44.98 g/day for the placebo, zinc, and zinc plus multi-

vitamins groups, respectively. They represent 67.7, 68.1,

and 63.4 of the RDA for the three groups, respectively.

The total fat intake was highest among pregnant women

of the zinc group, with a mean of 57 ± 52.71 g/day. The

mean intake of fat among the other two groups was

42.1 ± 21.75 and 44.5 ± 15.8 for the placebo and zinc plus

multivitamins groups, respectively.

In all groups, the mean carbohydrate intake was higher

than the RDA, representing 109.7, 121.1, and 112.2 of the

RDA.

Fiber intake was very low and constituted only about one

quarter of the recommendation (21.8, 23.6, and 22.4%,

respectively).

Table 1. Baseline biochemical characteristics of the three groups of pregnant women attending antenatal care centers

and participating in the randomized-controlled trial, Alexandria, Egypt, at enrollment

Groups

Biochemical characteristics Placebo Zinc Zinc plus multivitamins Total Test (P-value)

Serum zinc first (mg/dl) F = 3.700 (0.025)*Mean ± SD 60.2 ± 6.49 58.6 ± 6.87 59.2 ± 6.46

Hemoglobin (g/dl) F = 2.990 (0.051)Mean ± SD 10.46 ± 0.63 10.49 ± 0.64 10.35 ± 0.57o10 58 (26.0) 64 (28.4) 76 (33.5) 198 (29.3) w2 = 3.16 (0.206)10 + 165 (74.0) 161 (71.6) 151 (66.5) 477 (70.7)

*Significant at Po0.05.

Zinc status and dietary intake during pregnancy Naem et al. 37


The mean energy intakes were 1379.1, 1445, and

1343.9 kcal/day for the placebo, zinc, and zinc plus

multivitamins groups, respectively. They represent 51.1,

53.5, and 49.8% of the RDA for the three groups,

respectively. Except for fat (P = 0.022) and energy intake

(Po0.001), there was no statistically significant differ-

ence between the three groups.

Table 3 shows a comparison between the three groups

studied in the mean intake and percent adequacy of

micronutrients in relation to RDA. Intake of vitamin A

represents 60.8% of RDA during pregnancy. Differences

between the three groups studied were statistically

significant (P = 0.021).

The calcium mean intakes were 399.8, 417.2, and

360.1 mg/day for the placebo, zinc, and zinc plus multi-

vitamins groups, respectively. These mean intakes

represent 40, 42, and 36% of the RDA. Differences

between the three groups studied were statistically

significant (P = 0.041).

The mean iron intake in the three groups studied was

10.1, 10.4, and 9.3 g/day, respectively. They represent 37,

38.6, and 34.4 of the RDA of iron for pregnant women.

There was no statistically significant difference between

the three groups studied.

Zinc mean intake in the three groups studied was 6.8, 6.5,

and 6.5 mg/day, respectively. These mean intakes repre-

sent 62, 59.4, and 59.4% of the RDA. There were no

statistically significant differences among the three

groups studied in zinc intake.

Enhancer and inhibitors of zinc absorption

Table 4 shows the enhancers of zinc absorption in the

study subsample represented by protein of meat and fish.

In terms of the meat intake pattern, most of the study

sample (92%) consumed meat less than three times a

week, with comparable percentages of consumption.

Intake more than three times a week was rare and was

found in 5.0% of the total sample.

In terms of fish consumption, 82.0% of the total sample

consumed fish less than three times a week. Ten percent

of the study sample rarely consumed fish.

Consuming eggs less than three times per week was the

prevailing pattern among the majority of women (63%).

There were no statistically significant differences be-

tween the three groups studied in the consumption of

fish, meat, and egg.

Table 5 shows the intake of inhibitors of zinc absorption

in the subsample. In terms of vegetable consumption,

most of the study subsample (43%) consumed vegetables

more than three times a week.

With respect to milk consumption, about half of the study

sample (49.0%) consumed milk less than three times a

week. Daily consumption was nil and was found in 2.0%

of the total sample. Consumption of cheese more than

Table 2. Mean ± SD of intake and percent adequacy of the macronutrients of the subsample studied (n = 100)

Intake Groups Mean SD RDA % RDA P-value

Total protein (g/day) Placebo 48.08 16.12 71 67.7 0.098Zn 48.32 20.81 68.1

Zn + MM 44.98 13.92 63.4Total fat (g/day) Placebo 42.09 21.57 – 0.022

Zn 57.01 52.71Zn + MM 44.49 15.76

Carbohydrate (g/day) Placebo 191.97 68.26 175 109.7 0.087Zn 211.82 63.11 121.1

Zn + MM 196.33 47.36 112.2Energy (kcal/day) Placebo 1379.1 494.72 2743 51.1

Zn 1445 432.05 53.5 0.001Zn + MM 1343.9 384.94 49.8

RDA, recommended dietary allowance.

Table 3. Intake (mean ± SD) and percent adequacy of the micronutrients of the subsample studied (n = 100)

Micronutrients Groups Mean SD RDA % RDA P-value

Vitamin A (mcg/day) Placebo 422.31 202.71 770 54.85 0.021*Zn 468.05 197.16 60.79

Zn + MM 376.47 193.72 48.89Ca (mg/day) Placebo 399.76 172.98 39.89 0.041*

Zn 417.17 168.90 1000 41.72Zn + MM 360.07 196.02 36.00

Iron (mg/day) Placebo 10.09 3.81 37.00 0.098Zn 10.43 3.18 27 38.63

Zn + MM 9.30 2.50 34.44Zinc (mg/day) Placebo 6.82 1.45 62.00 0.108

Zn 6.53 1.57 11 59.36Zn + MM 6.53 3.30 59.36

RDA, recommended dietary allowance.*Significant at Po0.05.



three times a week was reported by the majority of

women (65%).

Likewise, consumption of beans more than three times

per week was reported by the majority of women (67%).

There was no statistically significant difference between

the three groups in the consumption of inhibitors of zinc

absorption.

DiscussionSerum zinc concentration decrease progressively during

the course of pregnancy in relation to blood volume

expansion. Thus, the values must be interpreted in

relation to the stage of pregnancy or serum albumin con-

centrations. Despite many limitations, serum zinc

concentration is still the recommended biochemical

indicator of zinc status during pregnancy at the popula-

tion level. In the present study, 53.3% of pregnant women

had serum concentration lower than the median values

for the stage of pregnancy. This high prevalence of zinc

deficiency is comparable with the rate reported by an

Indian study (64.6%) [12]. Studies carried out in

developing countries documented that zinc deficiency

in pregnant women is because of the low intake of dietary

zinc [12–14]. The present study was carried out in a

community that consumed a diet composed mainly of

vegetables and beans. The low intake of enhancers and

the presence of higher amounts of phytates and dietary

fibers in this diet, known to cause poor zinc absorption,

could be a major contributing factor toward the high

prevalence of zinc deficiency in this study population.

Also, populations with poor access to health, water, and

sanitation are at an increased risk of infectious diseases,

which increases the risk of zinc deficiency.

Because inadequate dietary intake of zinc is the most likely

cause of zinc deficiency, dietary assessment is an important

component in evaluating the risk of zinc deficiency.

Information on the adequacy of dietary zinc intakes should

be interpreted together with data derived from other

assessment methods, such as biochemical assessment [15].

Dietary surveys from 17 developing countries have shown

Table 4. Enhancers of zinc absorption among the three groups of the subsample (n = 100)

Groups

Enhancers Placebo Zinc Zinc plus multivitamins Total w2 P-value

MeatMore than 3 times a week [n (%)] 2 (6.1) 1 (2.9) 2 (6.1) 5 (5.0) 2.389 0.665Less than 3 times a week [n (%)] 30 (90.9) 31 (91.2) 31 (93.9) 92 (92.0)Rare consumption [n (%)] 1 (3.0) 2 (5.9) 0 (0.0) 3 (3.0)

FishMore than 3 times a week [n (%)] 2 (6.1) 3 (8.8) 3 (9.1) 8 (8.0) 1.717 0.788Less than 3 times a week [n (%)] 28 (84.8) 26 (76.5) 28 (84.8) 82 (82.0)Rare consumption [n (%)] 3 (9.1) 5 (14.7) 2 (6.1) 10 (10.0)

EggsDaily consumption [n (%)] 1 (3.0) 1 (2.9) 1 (3.0) 3 (3.0) 5.647 0.464More than 3 times a week [n (%)] 8 (24.2) 11 (32.4) 4 (12.1) 23 (23.0)Less than 3 times a week [n (%)] 21 (63.6) 20 (58.8) 22 (66.7) 63 (63.0)Rare consumption [n (%)] 3 (9.1) 2 (5.9) 6 (18.2) 11 (11.0)

Total [n (%)] 33 (100.0) 34 (100.0) 33 (100.0) 100 (100.0)

Table 5. Inhibitors of zinc absorption among the three groups of the subsample (n = 100)

Groups

Placebo Zinc Zinc plus multivitamins Total w2 P-value

VegetablesDaily [n (%)] 7 (21.2) 5 (14.7) 7 (21.2) 19 (19.0) 6.304 0.390More than 3 times a week [n (%)] 14 (42.4) 11 (32.4) 18 (54.5) 43 (43.0)Less than 3 times a week [n (%)] 10 (30.3) 16 (47.1) 7 (21.2) 33 (33.0)Rare consumption [n (%)] 2 (6.1) 2 (5.9) 1 (3.0) 5 (5.0)Milk

Daily consumption [n (%)] 1 (3.0) 0 (0.0) 1 (3.0) 2 (2.0) 2.579 0.859More than 3 times a week [n (%)] 11 (33.3) 8 (23.5) 11 (33.3) 30 (30.0)Less than 3 times a week [n (%)] 16 (48.5) 18 (52.9) 15 (45.5) 49 (49.0)Rare consumption [n (%)] 5 (15.2) 8 (23.5) 6 (18.2) 19 (19.0)

CheeseDaily consumption [n (%)] 0 (0.0) 1 (2.9) 0 (0.0) 1 (1.0) 7.954 0.242More than 3 times a week [n (%)] 17 (51.5) 22 (64.7) 26 (78.8) 65 (65.0)Less than 3 times a week [n (%)] 15 (45.5) 10 (29.4) 7 (21.2) 32 (32.0)Rare consumption [n (%)] 1 (3.0) 1 (2.9) 0 (0.0) 2 (2.0)

BeansDaily consumption [n (%)] 7 (21.2) 9 (26.5) 11 (33.3) 27 (27.0) 1.269 0.867More than 3 times a week [n (%)] 24 (72.7) 23 (67.6) 20 (60.6) 67 (67.0)Less than 3 times a week [n (%)] 2 (6.1) 2 (5.9) 2 (6.1) 6 (6.0)Rare consumption [n (%)] 0 (0) 0 (0) 0 (0) 0 (0)

Total [n (%)] 33 (100.0) 34 (100.0) 33 (100.0) 100 (100.0)



that zinc intake of women is on average 9.6 mg/day

(1.2 SD) in contrast to the 1990 RDAs of 15 and 19 mg,

respectively, during pregnancy and lactation. From these

data and application of the probability method, it was

calculated that 82% of pregnant women worldwide are

likely to have inadequate zinc intake. The prevalence may

be much lower now (B31%), with the recent RDA for zinc

being reduced to 11 mg for pregnancy and 12 mg for

lactation [16,17], but still raise a concern in terms of the

potential adverse effects of maternal zinc deficiency on

pregnancy outcomes.

In this study, the mean maternal dietary intake of zinc was

less than 7 mg/day in the three groups. These intakes

represent about 59.4, 59.4, and 62% of the recommended

recent RDA. Carbone et al. [18], in their study, reported

that the mean zinc intake among pregnant women at 20

and 36 weeks of gestation was B66% of the RDAs. Zinc

intakes reported by Osendarp et al. [19] in Bangladesh were

6.3 and 6.4 mg/day in the zinc-supplemented group and the

placebo group, respectively. The findings of the current

study are comparable with the figures reported by

Osendarp and colleagues. This may be because the

nutritional data in both studies were obtained approxi-

mately at the same time at about 4–5 months of gestation

and maternal nutritional status was very poor during this

period of gestation. Also, in a recent study in India [8], it

was found that the mean intake of zinc was 61.1 ± 16.6

mg/dl; this mean intake is also comparable with the intake

reported in this study.

In a recent study in Jordan [20] that included 700

pregnant women, it was found that the mean maternal

intake of zinc was 8.86 ± 0.14 mg/day. This figure is

higher than the findings of the present study and could

be attributed to the higher socioeconomic class of the

Jordanian women in that study.

The bioavailability of zinc is considerably influenced by

the composition of the diet in the content of inositol

phosphates (phytates), the total zinc content of the meal,

and the amount and source of protein. Animal protein is a

rich source of zinc and, in addition, exerts a possible

enhancing effect on the overall absorption of zinc from

the diet. It is well known that phytic acid is a strong

inhibitor of zinc absorption and a concomitant intake of

protein seems to counteract the negative effects on

absorption induced by high intakes of phytic acid [21].

Increasing the amount of total protein enhances zinc

absorption and if the protein is from cellular animal

sources, the enhancing effect is even greater [22].

There is additional protein requirement for a pregnant

woman to support the synthesis of maternal and fetal

tissues, but the magnitude of this increase is uncertain.

Protein requirement increases throughout gestation and is

maximum during the third trimester. The current RDA of

0.66 g/kg/day of protein for pregnant woman is the same as

that for nonpregnant women in the first half of pregnancy

and increases in the second half to 71 g/day [23].

The mean dietary protein intake in this study was 48.1,

48.3, and 44.98 g/day for the three groups, respectively.

This intake represents less than 70% of the RDA. The

protein intake in the Jordanian study [20] was

90.46 ± 0.95, which is obviously higher than the present

results. However, Osendarp et al. [19], in Bangladesh,

found a mean maternal protein intake of 40 and 39 g in

the zinc-supplemented and the placebo group, respec-

tively, figures that are comparable with the findings of the

present study. This could be because Osendarp and

colleagues carried out their study in an urban, poor

population in Bangladesh that may have characteristics

similar to those of the current study population.

The overall low protein intake in this study adds to the

lowered bioavailability of zinc in the study population.

A marked increase in iron consumption during pregnancy

considerably increases the demand for iron. A pregnant

woman must consume an additional 700–800 mg of iron

throughout her pregnancy: 500 mg for hematopoiesis and

250–300 mg for fetal and placental tissues. The 2001

RDA for iron during pregnancy is 27 mg/day, an increase

of 9 mg/day over that for nonpregnant women [23].

The mean iron intake in this study was 10.1, 10.4, and

9.3 mg/day for the three groups, respectively. This intake

comprises less than 40% of the RDA. It is lower than that

reported by Osendarp et al. [19], who reported 11.3 and

11.7 mg/day for the zinc-supplemented group and the

placebo group, respectively. The Jordanian study [20] also

found a mean intake of 13.46 ± 0.27 mg/day. Actually, iron

intake in the present study was very low and covered only

about one-third of the RDA for pregnant women. This could

be because of the vegetarian diet usually consumed in our

country, which leads to low bioavailability of iron (animal

proteins are usually the best sources of iron) and high intake

of inhibitors of iron absorption (phytates and oxalates).

Additional energy is required during pregnancy to support

the metabolic demands of pregnancy and fetal growth.

Metabolism increases by 15% during pregnancy. It is

difficult to specify precise energy requirements because

they vary with pregnancy weight, amount and composi-

tion of weight gain, and stage of pregnancy and activity

level [24]. In the present study, the findings of the 24-h

recall showed that the mean maternal energy intake was

around 50% of the 2004 RDA (2743 kcal/day) for the

three groups studied. The low level of intake of energy in

the current study may be because of decreased appetite

in the beginning of the second trimester at the time of

collection of nutritional data. However, energy intake in

this study was comparable with the findings reported by

Osendarp et al. [19] in Bangladesh slums, where the mean

energy intakes were 1400 and 1488 kcal/day for the zinc-

supplemented group and the placebo group, respectively.

In the study carried out in Jordan [20], the mean energy

intake was about 2593.8 kcal/day; this figure may show

that our country may have nutritional problems in

comparison with other Middle East countries. Nielsen

et al. [25], who carried out a prospective study on

pregnant women living in the US state of North Carolina,

reported a median energy intake of 2470.2 kcal/day. This

difference in the daily energy intake between the present

study and other studies may be attributed to the



methodology of recall and its timing in the early period

of the second trimester.

Conclusion and recommendationsWomen in the present study had multiple nutritional

deficiencies. More than half of the screened women had

serum zinc values lower than the average for the trimester

of pregnancy. The intake of all studied nutrients except

carbohydrates was low compared with that found in some

other developing countries. Zinc intake represented

about 60% of the RDA. The iron intake was below 50%

of the RDA. Protein intake represents less than 70% of

the RDA and the mean energy intake was less than 40%

of the RDA. The following are recommended:

(1) Zinc should be included in the prenatal supplemen-

tation programs in women at risk of zinc deficiency in

Egypt as the occurrence of multiple micronutrient

deficiency is more likely than the occurrence of

a single deficiency.

(2) Nutritional health education should be used as a

preventive approach to allow the large sector of the

low-income population in our society to maximize the

use of the limited resources in the best way.

AcknowledgementsConflicts of interestThere are no conflicts of interest.

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