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Indian Pediatr 2011;48: 47-49 |
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Prevalence of Clinical and Sub-Clinical
Vitamin A Deficiency Among Rural Preschool Children of West
Bengal, India |
N Arlappa, N Balakrishna, A Laxmaiah, K Madhavan Nair and GNV Brahmam
From the National Institute of Nutrition (ICMR), Jamai
Osmania, Hyderabad 500 007, India.
Correspondence to: Dr N Arlappa, Scientist D, Division of
Community Studies, National Institute of Nutrition, (ICMR), Jamai-Osmania,
PO, Hyderabad 500 007, Andhra Pradesh, India.
Email: [email protected]
Received: October 09, 2009;
Initial review: November 11, 2009;
Accepted: March 08, 2010.
Published online: 2010 August 1.
PII: S097475590900727-2
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Abstract
A community based cross-sectional study was carried
out in rural areas of West Bengal with the aim to assess the prevalence
of vitamin A deficiency (VAD) among rural preschool children. Clinical
examination was carried out on 9,228 children for the signs and symptoms
of VAD and a sub-sample of 590 children were covered for the estimation
of blood vitamin A levels using dried blood spot (DBS) method. The
prevalence of Bitot’s spots was 0.6% (95% CI=0.44, 0.76), which is more
than the public health significance, and it increased with increase in
age. The prevalence was significantly higher (P<0.001) among boys
(0.8%) as compared to girls (0.4%). The proportion of children with
subclinical vitamin A deficiency (blood vitamin A < 20µg/dL) was 61%
(95% CI: 52.3-65.1), and it was significantly (P<0.01) higher
among the children of lower socioeconomic communities.
Key words: Bitot’s spots, India, Preschool children, Vitamin A
deficiency.
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V itamin A deficiency (VAD) is the
most important cause of preventable blindness in young children [1] and is
closely associated with increased frequency of respiratory infections,
diarrhea, measles and childhood mortality [2,3]. Not many studies are
available on prevalence of VAD among the rural preschool children in
India. Such studies would be useful to initiate nutrition intervention
programs in deficient areas. Keeping in view of the magnitude of the
problem, the National Nutrition Monitoring Bureau (NNMB) carried out this
survey. The objective was to assess the prevalence of VAD among the rural
preschool children of West Bengal.
Methods
A population based cross-sectional study was carried
out adopting the multi-stage stratified random sampling procedure. The
district or part of the district with a population of 1.8 million was
considered as one stratum. A total of 16 strata were selected randomly
from the State, and a sub-sample of 80 villages at 5 villages per stratum
was selected randomly from 16 strata.
Assuming the prevalence of Bitot’s spots as 1% [4],
confidence interval (CI) of 95% and relative precision of 20%; a sample
size of 9,508 was arrived for the clinical VAD at the State level.
Similarly, by assuming the prevalence of subclinical VAD as 50% [5],
confidence interval (CI) of 95% and relative precision of 10%, the sample
size arrived at was 400 preschool children. The village was divided into
five geographical areas based on natural groups of houses or streets. The
required number of children to be covered in a village and in each
geographical area was determined on the basis of probability proportional
to size (PPS) method.
Clinical examination was carried out on a total of 9228
preschool children to assess the clinical VAD, and a sub-sample of 590
children were covered for the estimation of blood vitamin A from dried
blood spot (DBS), using high-pressure liquid chromatography [6]. Ethical
clearance was obtained from National Institute of Nutrition Ethical Review
Board. Written informed consent was obtained from the parents.
The data were analyzed using Statistical Package for
Social Sciences; version 15.0 for windows [7]. Bivariate analysis was
performed by the chi-square test to study the association between the
prevalence of VAD and socio-demographic variables. Step-wise logistic
regression was performed to identify the best set of socio-demographic
variables associated with the prevalence of VAD.
Results
Distribution of prevalence of VAD among pre-school
children by age group and gender is presented in Table I.
The results show that the overall prevalence of Bitot’s spot, in
pre-school children was 0.6% (95% CI 0.44-0.76), and the prevalence was
significantly (P<0.001) higher among the children of 3-5 year age
group (compared to the children of 1-3 year age group) and among boys (as
compared to girls). The median blood vitamin A was 16.6 µg/dL (95% CI
3.9-62.6) (Table II).
TABLE I
Prevalence (%) of Vitamin A Deficiency (VAD) by Age Group and Gender
|
N |
NB |
Conjunctival* |
Bitot’s* |
VAD†* |
|
|
|
xerosis |
spots |
|
Age group |
|
|
|
|
|
1-2+ |
3932 |
0.1 |
0.8 |
0.1 |
0.9 |
3-4+ |
5296 |
0.2 |
5.8 |
1.0 |
6.0 |
Pooled |
9228 |
0.2 |
3.7 |
0.6 |
3.8 |
Boys |
4492 |
0.2 |
4.6 |
0.8 |
4.8 |
Girls |
4736 |
0.1 |
2.8 |
0.4 |
2.9 |
*P<0.001 both for age group and gender; †total vitamin A deficiency; NB: night blindness.
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TABLE II
Blood Vitamin A Levels (µg/dL) by Age Group and Gender
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n |
Mean ± SD |
Median |
Range |
< 20µg/dL (%) |
95% CI |
Age group |
|
|
|
|
|
|
Age 1-2 + (y) |
233 |
19.1 ± 10.05 |
18.1 |
3.9-62.6 |
55.4 |
49.0-61.8 |
Age 3-4 + (y) |
357 |
18.3 ± 8.92 |
16.3 |
4.4-60.0 |
65.0 |
60.1-69.9 |
Pooled |
590 |
18.6 ± 9.39 |
16.6 |
3.9-62.6 |
61.2 |
52.3-65.1 |
Boys |
282 |
18.7 ± 9.42 |
16.7 |
4.4-62.6 |
60.3 |
54.6-66.0 |
Girls |
308 |
18.6 ± 9.37 |
16.6 |
3.9-60.0 |
62.0 |
56.6-67.4 |
The prevalence of VAD was significantly (P<0.01)
higher among the children of scheduled tribes and scheduled castes
compared to children of other communities. Family size, occupation,
literacy level did not have any bearing on the prevalence of VAD. Stepwise
logistic regression analysis revealed that the age group and community are
positively associated with the prevalence of Bitot’s spots, where the
preschool children belonging to scheduled tribe (OR =4.5; 95% CI:
2.1-10.5) and children of 3-5 years (OR =1.4; 95% CI: 1.0-2.0) were at
higher risk for VAD.
Discussion
Prevalence of VAD is a public health concern among the
children residing in rural areas of West Bengal. Although the prevalence
of clinical VAD was below the figures reported for rural preschool
children of India (0.8%) [8] and Maharashtra (1.3%) [9], the subclinical
vitamin A deficiency which is considered as prolonged dietary deficit of
vitamin A was high (61%) compared to the prevalence among the children of
Maharashtra (55%) and that reported from Nigeria (29.5%) [9,10].The major
contributing factors for high prevalence of VAD are poor dietary intake of
vitamin A and an increasing reliance on basic staples. About 81% of
pre-school children of West Bengal were not consuming even 50% of the RDA
of vitamin A [11].
The coverage of preschool children for biannual massive
dose vitamin A was only 4% as against the 23%(5) and 30% [12] at the
National level. Hence, there is a need to strengthen the existing massive
dose vitamin A program to minimize the prevalence of VAD. It is also
necessary to encourage the community to consume variety of foods rich in
vita-min A and other micronutrients through dietary diversification and
horticulture intervention to en-sure nutrition security, through Health
and Nutrition Education (HNE) and appropriate Information, Education and
Communication (IEC) activities.
Acknowledgments: Dr Bandopadhaya, Medical
Officer and Mrs Sudeshna, Nutritionist, National Nutrition Monitoring
Bureau (NNMB), West Bengal State unit; Dr Raghu P, Scientist B, and Mr
Vikas Rao V, Technical Officer, Micronutrient Research; and Dr
Mallikarjuna Rao K, Galreddy CH, Sharad Kumar, Ravindranath M and Mr
Santosh Kumar Sahu, all from Division of Community Studies; for being part
of the study group; and Miss Sarala, Mr Hanumantha Rao G and Mrs
Prashanthi G for secretarial support.
Contributors: All authors conceived and designed
the study proposal and revised the manuscript for important intellectual
content. AN: Review literature, manuscript preparation, preparation and
pretesting of proforma, and quality control of data collection; BN: Data
analysis, statistical interpretation of data; LA: planning and preparation
and pre-testing of proforma, quality control of data collection, report
writing. KMN: assessment of blood vitamin A by DBS and editing the
manuscript, GNVB: co-ordinate the planning of project proposal, and
manuscript preparation.
Funding: ICMR.
Competing interests: None stated.
What This Study Adds?
• VAD is major public health problem among rural
preschool children of West Bengal, and the prevalence is
significantly higher in the 3-5 years age group.
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