As the author stated, we have not assessed the night blindness, the early
symptom of VAD in 12-24 month children. Only four children (0.1%) had
night blindness among 3932 children of 1-2+ years i.e. 12-36 months.
However, the four children are in the age group of 24-36 months. Since we
divided the pre-school children into two age groups, we analyzed and
presented the data accordingly.
Similarly, we have not presented the prevalence of
conjunctival xerosis as an independent indicator of VAD, since it is the
subjective sign of VAD. Thus, we just presented the prevalence of night
blindness and conjunctival xerosis, as these are also the manifestations
of VAD. Similarly, we neither mentioned them as sole indicators of VAD nor
related them with socioeconomic status in text. Our entire focus in this
communication is only on Bitot’s spot, an objective sign of VAD and blood
vitamin A levels.
The author rightly pointed out that the blood retinol
would decrease if the particular children were suffering from
acute/chronic infections. In the present study, we have not estimated the
C-reactive proteins to indicate acute/chronic infections. However, de pee
and Omar reported that populations with a high prevalence of infection are
also more likely to suffer from VAD . Even if we estimated the
C-reactive proteins and deleted the subjects with high C-reactive
proteins, the prevalence of sub-clinical VAD may not differed have lot as
NNMB reported the prevalence of fever and acute respiratory infections as
2.7% and 1%, a respectively for the corresponding period . Similarly,
the diets of rural pre-school children were grossly deficit in terms of
vitamin A, where the median intakes were deficient by 66-81% as against
the RDA of 400 µg. The median vitamin A intakes of 84% of pre-school
children were not even 50% of their RDA .
Serum retinol is the preferred indicator for population
level assessment of VAD, and it is the best-established biochemical
indicator of vitamin A status . Similarly, estimation of Serum retinol
from dried blood spot (DBS) is a validated and established method [4-6].
The DBS methodology has been validated before it was
operationalized. We have had external validation of the DBS and the
conventional methodologies with Craft Technologies, Wilson, USA and
currently taking part in the external Vital EQ programme of CDC, Atlanta,
USA. We don’t believe that the methodology underestimates vitamin A value.
There are limited studies to cite the subclinical deficiency of vitamin A.
Using the conventional method, the subclinical deficiency of vitamin A was
reported to be 55% in school children 6-18 years from a middle-income
residential school near Hyderabad .
This survey was carried out during the year 2003.As, we
are asked to submit the manuscript as "Short communication" we condensed
the original manuscript to meet the word count.
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vitamin A deficiency: Serum retinol and serum retinol binding protein. J
2. National Nutrition Monitoring Bureau (NNMB). Diet
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Hyderabad, India. Report No.21: 2002.
3. National Nutrition Monitoring Bureau (NNMB). Diet
and Nutritional Status of Population and Prevalence of Hypertension Among
Adults in Rural areas. Hyderabad, India: National Institute of Nutrition,
Indian Council of Medical Research; Report No.24: 2006.
4. Craft NE, Bulex J, Valdez C, Li Y, Solmons NW.
Retinol concentration in capillary dried blood spots from healthy
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Ravinder P, Shatrugna V, et al. Effect of micronutrient supplement
on health and nutritional status of school children: Biochemical status.
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Rao V, Madhavan Nair K, et al. Prevalence of vitamin A deficiency
and its determinants among the rural pre-school children of Madhya
Pradesh, India. Ann Hum Biol. 2011;38:131-6.