We read with interest the manuscript entitled "Relevance of Continuation
of Universal Vitamin A Supplementation Program in India" . The
following pertinent aspects need to be carefully considered prior to
interpreting the findings in relation to national policy on VAD.
It was reported by authors that the prevalence of
clinical vitamin A deficiency (VAD) has declined considerably in India, as
compared to previous years . However, they found a high prevalence of
blood vitamin A deficiency (<20 µg/dL), a criteria for sub-clinical VAD
. In their data, 61% preschool children had sub-clinical VAD, and with
this criterion, a public health problem was diagnosed in all the NNMB
states surveyed, ranging from 52% in Maharashtra to 88% in Madhya Pradesh.
The proportion of severe blood VAD (<10 µg/dL) was 21.5%, again indicating
a severe public health problem in all the NNMB states .
This NNMB survey  was conducted in the year
2000-2001 in rural areas of eight States viz., Andhra Pradesh, Karnataka,
Kerala, Madhya Pradesh, Orissa, Tamil Nadu, Maharashtra and West Bengal.
The Blood vitamin A levels were assessed in a subsample of preschool
children by dry blood spot technique (DBS), using HPLC at the National
Institute of Nutrition (NIN) . There was an average gap of 220 days
between the collection of sample and analysis due to delay in
commissioning of analytic facility. . The findings of this NNMB survey
 were reviewed by an expert committee constituted by the ICMR to
explain the contradictory scientific findings on VAD. For example, the
prevalence of Bitot’s spots among preschoolers in the State of Kerala was
nil; however, the prevalence of sub-clinical form of vitamin A deficiency
was the maximum . This committee recommended a resurvey on a sub-sample
of 50 children of 1-5 year age group (@ 10 children per village, from 5
villages) in the States of Kerala, Madhya Pradesh (high prevalence of
sub-clinical VAD) and Andhra Pradesh (low prevalence) by covering one
district each during the same season. The clinical signs of vitamin A
deficiency and blood vitamin A levels were documented simultaneously. It
was also suggested that in each of these district, all those villages
surveyed earlier be covered in a repeat survey, by adopting similar
sampling procedures. The Repeat surveys were carried out in the districts
of Mallapuram in Kerala, Srikakulam in Andhra Pradesh and Seoni in Madhya
Pradesh. The children were examined for prevalence of clinical signs of
vitamin A deficiency, and blood vitamin A levels were estimated from
Finger prick blood samples by DBS method, as was done in the earlier
survey. The median blood vitamin A levels in all the three states during
the repeat survey were around 20 µg/dL.
The prevalence of children having blood vitamin A
levels of <20 µg/dL was about "half" of that observed earlier in the
States of Kerala (52% vs 93%), Andhra Pradesh (45% vs 80%)
and Madhya Pradesh (50% vs 100%) .
Validity of serum retinol estimated by DBS is low
because the children from whom DBS samples are collected, acute-phase
proteins like serum C reactive protein levels (CRP) are not done. Hence,
no adjustments can be made in the final value of Serum retinol levels
values obtained by DBS method. The changes in vitamin A metabolism during
the acute phase response have been reviewed extensively and documented
[6,7]. Reductions in plasma retinol have been described during the acute
phase of a wide range of infections . In light of frequent sub-clinical
infections, these NNMB surveys have probably overestimated the prevalence
of VAD because concomitant CRP levels were not used for correcting blood
vitamin A levels.
Scientists in India has been advocating targeted
distribution of synthetic vitamin A to the areas where there is
significant clinical VAD. Thus, the conclusion of the authors that there
is no need "to stop supplementation of vitamin A to pre-school children
hastily" are subject to misinterpretation and likely to create confusion
with regards to vitamin A supplementation policy in country.
1. Arlappa N, Ravikumar BP. Relevance of continuation
of universal vitamin A supplementation program in India. Indian Pediatr.
2. Toteja GS, Singh P, Dhillon BS, Saxena BN. Vitamin A
deficiency disorders in 16 districts of India. Indian J Pediatr.
3. World Health Organization (WHO). Indicators for
assessing Vitamin A deficiency and their application in monitoring and
evaluating intervention programs. Geneva: WHO;1996.
4. National Nutrition Monitoring Bureau (NNMB).
Prevalence of Vitamin A Deficiency among Rural Preschool Children.
Hyderabad, India: National Institute of Nutrition, Indian Council of
Medical Research. Report No 23;2006.
5. Craft NE. Retinol analysis in dried blood spots by
HPLC. J Nutr. 2000;130:882-5.
6. Filteau SM. Vitamin A and the acute-phase response.
7. Christian P, Schulze K, Stoltzfus RJ, West KP Jr.
Hyporetinolemia, illness symptoms, and acute phase protein response in
pregnant women with and without night blindness. Am J Clin Nutr.
8. Filteau SM, Tomkins AM. Micronutrients and tropical infections.
Trans R Soc Trop Med Hyg. 1994;88:1-3.