Iron deficiency anemia is most common nutritional deficiency disorder in India and remains a formidable health challenge. Girls in the period of later school age and early adolescence are prone to develop iron deficiency. Iron deficiency leads to many non-hematological disturbances which include growth and development, depressed immune function in infants; reduces physical work capacity; decreases the cognitive function in both infants and adolescents. Present study was done to know the prevalence of iron deficiency in both the anemic and non anemic school going adolescent girls, to assess the effect of iron deficiency on cognitive functions in anemic iron deficient and non-anemic iron deficient school girls in a village school situated in central India.
Iron deficiency is the third greatest global health risk after obesity and unsafe sex [
Iron deficiency has both physiologic and pathologic causes. Physiologic causes relate to the greater iron demands during periods of growth and development whereas pathologic causes refer to iron losses secondary to a chronic medical condition. In general, iron deficiency results when iron demands by the body are not met by iron absorption. Thus, iron deficiency can result from inadequate intake, impaired absorption, increased requirements, and chronic blood loss.
More than half of the world’s undernourished population lives in India [
Iron deficiency is a systemic condition which has many non ematological consequences, which occurs in relation to its severity, like decreased physical work capacity [
In present study, effort has been made to assess the effect of iron deficiency on cognitive functions in anemic iron deficient and in nonanemic iron deficient school going adolescent girls in a village school.
The present study was carried out in the Department of Pathology, MGIMS, Sevagram, India from July 2007 to September 2009. Approval was obtained from the Institutional Ethics Committee for the study.
A secondary school in the neighborhood, having girl students in the age group of 12−15 years studying in sixth to ninth standard was selected. Necessary permission was taken from the school authority and girls were explained in detail about the study in the school assembly. Participation in the screening programme was voluntary. An explanatory letter and consent form was given to all the girls. Written consent was obtained from parents or guardian for participation in the screening as all participants were minor. Participants completed a questionnaire asking for significant family, medical and menstrual history, parent education, and their dietary habits.
Screening for anemia and iron deficiency was done by (1) complete blood count: done by automatic cell counter, that is, Coulter for hemoglobin concentration. (2) estimation of serum ferritin concentration was done by ELISA. For this recommended protocol by the kit used was followed. Established age adjusted values for hemoglobin and serum ferritin were used.
The participants after screening were divided into three groups.
After dividing the participants into three groups, that is, anemic iron deficient (group I), nonanemic iron deficient (group II), and nonanemic noniron deficient (group III), for assessing the cognitive function mathematics score, one multicomponent test for memory, attention and verbal learning, and intelligent quotient (IQ) scores of the students was used.
For assessment of scholastic performance, the mathematics score obtained in the final term examination was noted from the report card. The score obtained were from total 100 marks.
Multicomponent test of the three groups was assessed after randomization by using PGI test—(Dr. N. N. Wig & Dr. Dwarka Prasad) for testing memory attention and verbal learning [
For assessing the intelligent quotient of the girl student’s, Bhatia battery performance test—(Dr. C. M. Bhatia) for intelligent quotient (I.Q) was used, which includes two subtest Kohl’s block design and Pass along test [
All these tests were selected because these have Indian norms and are constructed and standardized in India.
Out of total 110 girl students in the age group of 12–15 years, consent was obtained from 103 students to participate in the study. Subsequently 100 students were tested for hemoglobin concentration, serum ferritin, and cognitive function. (3 students refused to give blood for test.)
63 of 100 girl students had hemoglobin levels less than 12 gm% and 37 had hemoglobin levels above 12 gm%. Thus, prevalence of anemia in school going adolescent girls was 63%. The overall mean hemoglobin in the study was
Out of the 63 girl students who had anemia, 56 girls (56%) had Hb values between 10 and 12 gm%, 5 girls (5%) had Hb values between 7 and 10 gm%, and rest of the 2 girls (2%) had Hb values below 7 gm%. Thus, mild anemia (Hb 10–12 gm%) was present in 56% of the study subjects, moderate anemia (Hb 7–10 gm%) in 5%, and severe anemia (Hb < 7 gm%) was present in only 2% of the study subjects.
Serum ferritin was done in 100 girl students between the age group of 12−15 years, 67 were iron deficient (serum ferritin <12
Out of 63 girls who were anemic, 50 girls had reduced serum ferritin. Since the total number of students was 100 thus, the prevalence of iron deficiency anemia was 50% and rest of the 13 girls who were anemic, the cause of anemia was other than iron deficiency (see Table
Number of students in different groups, mean serum ferritin, and hemoglobin levels.
Groups | Number of students | Mean serum ferritin (µg/L) | Mean hemoglobin levels (gm%) |
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Anemic iron deficient (group I) | 50 | 8.458 | 11.01 |
Nonanemic iron deficient (group II) | 17 | 10.02 | 12.61 |
Nonanemic noniron deficient (group III) | 20 | 25.275 | 12.975 |
The mean mathematics score of the girl students in different groups.
Groups | Mean mathematics score ± SD |
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Anemic iron deficient (group I) ( |
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Nonanemic iron deficient (group II) ( |
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Nonanemic noniron deficient (group III) ( |
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SD: Standard deviation.
The mean multicomponent test (MCT) scores in the three different groups.
Test | Anemic iron deficient (group I) |
Nonanemic iron deficient (group II) |
Nonanemic noniron deficient (group III) |
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Recent memory |
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Remote memory |
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Mental balance |
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Attention and concentration |
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Delayed recall |
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Immediate recall |
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Verbal retention for similar pairs |
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Verbal retention for dissimilar pairs |
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Visual retention |
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Recognition |
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Total test scores |
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SD: Standard deviation.
The mean scores in Kohl’s block design, pass along test, and mean IQ score.
Groups | Kohl’s block design | Pass along test | Test quotient (TQ) | Mean intelligent quotient (±SD) |
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Anemic iron deficient (group I) | 11.86 | 12.76 | 193.06 | 96.6 (±7.28) |
Nonanemic iron deficient (group II) | 12.82 | 15.47 | 205.17 | 102.61 (±6.33) |
Nonanemic noniron deficient (group III) | 14.4 | 16.9 | 215.65 | 107.82 (±4.95) |
SD: Standard deviation.
For assessing the cognitive function, mathematics score, one multicomponent test for verbal learning, attention and memory, and IQ scores was used. For assessing the scholastic performance, the mathematics scores obtained in the final term examination was noted from the report card. The scores obtained were from a total of 100 marks. Mean mathematic score calculated for three groups.
The difference in mathematics score was highly significant (
Multicomponent test (MCT) of verbal learning, attention, memory and IQ scores of all the three groups was assessed after randomization. Tests were administered under the guidance of trained research assistant of the Department of Psychological Medicine. The person who was assessing the tests was unaware of the group assignment.
The difference in scores of mental balance between the nonanemic noniron deficient (group III) and anemic iron deficient (group I) was significant (
Non anemic non iron deficient (group III) and anemic iron deficient (group I) when compared for scores of Verbal Retention for Similar Pairs showed significant difference (
The difference in scores of verbal retention for dissimilar pairs between the anemic iron deficient (group I) and nonanemic iron deficient (group III) was statistically significant (
The scores of recognition between the anemic iron deficient (group I) and nonanemic iron deficient (group III) showed significant difference (
For assessing the intelligent quotient (IQ) of the girl students two test, that is, Kohl’s block design test and Pass along test were used. After obtaining the test quotient (TQ) from these two tests the IQ was calculated.
The IQ levels differed significantly between nonanemic noniron deficient (group III) and anemic iron deficient (group I) with
Thus, the cognitive function scores which included the mathematics score, multicomponent test scores, and IQ scores were less in iron deficient both anemic and nonanemic groups (group I and II) than the noniron deficient nonanemic group (group III).
Although all the features of cognition are important but verbal learning and attention and concentration along with memory are particularly more important for academic performance.
In present study, iron deficient both anemic and nonanemic students had scored less in mathematics than the normal non iron deficient students. This is in accordance to the study done by Prestonjee [
Multicomponent test of verbal learning, attention, and memory of all the three groups was assessed after randomization. The overall total score was less in iron deficient both anemic and nonanemic groups than noniron deficient nonanemic group.
Similar findings were also seen in scores of mental balance and verbal retention for similar and dissimilar pairs. There was no difference in score of recent and remote memory, delayed and immediate recall, and visual retention subsets between iron deficient (group I and II) and noniron deficient (group III).
The findings suggest that iron deficiency, even in the absence of anemia causes decrease in at least some aspect of cognitive functioning.
The present findings are in accordance with the findings of a randomized trial done by Bruner et al. [
The difference of mean IQ scores between iron deficient both anemic and nonanemic groups (I and II) and nonanemic noniron deficient was statistically significant.
Pollitt et al. [
The findings of the present study are iron deficient school going adolescent females both anemic and nonanemic had low scholastic performance in the form of low mathematics score and low scores in verbal learning, attention, mental balance, and recognition component of multicomponent test along with low IQ scores than their noniron deficient comparers. Iron deficiency independently leads to decreased cognitive scores. Iron deficiency without anemia is the initial stage and as the iron deficiency increases anemia manifests. The cognitive scores were lowest in the iron deficient anemic (group I). In iron deficient without anemia it was slightly more than group I but much less than group III, that is, nonanemic noniron deficient subjects. Prevalence of anemia was 63% while prevalence of iron deficiency anemia in present study was 50%.
There is need to initiate programme for supplementation of iron and folic acid to school going adolescent girls for the prevention of hematological and nonhematological consequences of iron deficiency with government and private organizational efforts.
Consent was obtained from Institutional Ethical committee of Mahatma Gandhi Institute of Medical Sciences, Sevagram, India.
The authors declare there is no conflict of interests.