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Brief Reports

Indian Pediatrics 2004; 41:165-169 

Current Status of Iodine Nutriture and Iodine Content of Salt in Andhra Pradesh

 

Umesh Kapil, Preeti Singh and Priyali Pathak

From the Department of Human Nutrition, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110 029.

Correspondence to: Dr. Umesh Kapil, Additional Professor, Department of Human Nutrition, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110 029.
 E-mail: [email protected]

Manuscript received: August 28, 2002, Initial review completed: October 1, 2002; Revision accepted: May 9, 2003.

Abstract:

A cross sectional survey was conducted in the year 2001, to establish the current status of iodine nutriture and level of salt iodisation in the state of Andhra Pradesh, India.

All the 23 districts were included. The data was collected in each district through school approach. A total of 3706 salt samples and 1952 casual urine samples were collected. Nearly 45% of the population was found to be consuming iodised salt. All the districts had adequate iodine nutriture except Rangareddy and Cuddapah. The districts which were earlier found endemic to iodine deficiency namely Srikakulam, Vizianagaram, Visakhapatnam, Godavari, Khammam, Adilabad and Warrangal were found with adequate iodine nutriture as reflected by median UIE level of more than 100 µg/L. The study revealed success of salt iodisation program in the state.

Key words: Iodine deficiency, mental retardation, iodized salt, urinary iodine excretion level

Iodine deficiency is the most common preventable cause of mental retardation in the world today(1). Surveys conducted in 282 districts of India have identified 242 districts as endemic to iodine deficiency(2). The Government of India had initiated a National Iodine Deficiency Disorders Control Program (NIDDCP) for prevention of iodine deficiency disorders (IDD). Under the NIDDCP program, there is a policy of universal salt iodization under which the entire population of the country is to receive iodized salt with a minimum of 15 ppm of iodine. However, the Government of Andhra Pradesh had implemented a partial ban on sale of non-iodized salt for edible purposes in iodine endemic districts only(3).

The consumption of iodised salt has been reported to be low by the population in Andhra Pradesh(4). The recent National Family Health Survey (NFHS) II conducted in 1998-1999 also revealed that in Andhra Pradesh as high as 72.5% of the salt samples had iodine content less than the stipulated level of 15 ppm(4). The present study was conducted to establish the current status of iodine nutriture and level of salt iodisation in different districts of Andhra Pradesh in the year 2001 so that the corrective measures can be initiated to prevent IDD.

Subjects and Methods

The study was undertaken in all the 23 districts of Andhra Pradesh during the year 2001. The guidelines recommended by WHO / UNICEF / lCCIDD for a rapid assessment of salt iodisation in a district was adopted(1). In each district all the senior secondary schools were enlisted and one school was selected by random sampling for the detailed study. One hundred and fifty children in the age group of 11 to 18 years studying in the school were included in the study and briefed about the objectives of the study during the morning assembly. Children belonging to different villages attending the school on the day of the survey were identified and were provided with auto seal polythene pouches with an identification slip. They were requested to bring four tea spoons of salt (about 20 g) from their family kitchen. A minimum of 100 salt samples were collected from each district by utilizing the uniform sampling methodology. The iodine content of salt samples was analyzed using the standard iodometric titration method(5). An internal quality control sample having a known concentration range of iodine content was run with every batch of test samples. If the results of the internal quality control sample was within the range then the test was deemed in control and if the results were outside the range, then the whole batch was repeated.

More than 35 children from the same school were randomly selected and were requested to provide "on the spot" casual urine samples. Plastic bottles with screw caps were used to collect the urine samples. The samples were stored in the refrigerator until analysis. The urinary iodine excretion (UIE) levels were analyzed using the wet digestion method(6). An internal quality control sample having a concentration range of iodine content was run with every batch of test samples, as specified above. In addition to the proportion of children consuming iodised salt and their urinary iodine excretion levels, 95% confidence interval was also worked out.

Results

A total of 3706 salt samples were collected from 23 districts of Andhra Pradesh. The district wise distribution of iodine content of salt is depicted in Table I. It was observed that 55% of the families were consuming iodised salt with more than 5 ppm. In other words, the 95% confidence interval of these families was 52.9% to 57.2%. It was found that in the coastal districts of Nellore, Rangareddy, Vishakhapatnam, Anatpur, East Godavari, Kurnool, Prakasam and Mehaboobnagar districts less then 10% of the families were consuming salt with iodine content of 15ppm .

Table 1
Iodine Content of Salt Samples Collected at Beneficiaries Level in
Andhra Pradesh (n = 3706)
    Iodine Content (ppm)  
Name of the District N <5 5-15 15 & more
Nellore 
119 
95(79.8) 
21(17.6) 
3(2.5) 
Rangareddy 
204 
134(65.7) 
62(30.4) 
8(3.9) 
Vishakhapatnam 
205 
156(76.1) 
39(19.0) 
10(4.9) 
Anantpur 
155 
78(50.3) 
69(44.5) 
8(5.2) 
East Godavari
152 
63(41.4) 
79(52.0) 
10(6.6) 
Kurnool 
106 
9(8.5) 
88(83.0) 
9(8.5) 
Prakasam
150 
125(83.3) 
11(7.3) 
14(9.3)
Mehboobnagar 
100 
13(13.0) 
77(77.0) 
10(10.0) 
Cuddapah 
155 
94(60.6) 
43(27.7) 
18(11.6) 
Nalgonda 
150 
93(62.0) 
38(25.3) 
19(12.7)
Srikakulam
205 
25(12.2) 
153(74.6) 
27(13.2) 
Warangal 
158
69(43.7) 
67(42.4) 
22(13.9) 
West Godavari 
148 
77(52.0) 
50(33.8) 
21(14.2) 
Chitoor 
183 
61(33.3) 
84(45.9) 
38(20.8) 
Vijaynagram
211
93(44.1)
72(34.1)
46(21.8)
Nizamabad 
200 
110(55.0) 
46(23.0) 
44(22.0) 
Krishna 
150 
107(71.3) 
6(4.0) 
37(24.7) 
Khammam
150
79(52.7)
33(22.0)
38(25.3)
Guntur 
150 
60(40.0) 
43(28.7) 
47(31.3)
Adilabad 
155 
34(21.9) 
70(45.2) 
51(32.9) 
Medak
150
61(40.7)
37(24.7)
52(34.6)
Hyderabad 
200 
4(2.0) 
114(57.0) 
82(41.0) 
Karimnagar
150
23(15.3)
56(37.3)
71(47.4)
Total
3706
1663(44.9)
[42.5 - 47.2]*
1358(36.6)
[34.1 - 39.1]*
685(18.5)
[15.6 - 21.4]*
Figures in parentheses denote percentages;   * 95% Confidence interval.

 

Table II depicts the district-wise distribution of UIE levels. It was found that districts Rangareddy and Cuddapah had median UIE less than 100 µg/L along with more than 20% of the urine samples with less than 50 µg/L of iodine. These findings indicated deficient iodine nutriture in the population studied. This finding was further substantiated by the fact that in both these districts more than 60% of the families were consuming iodised salt with less than 5 ppm.

Table II

Urinary Iodine Excretion levels in the Study Subjects in Andhra Pradesh (n = 1952)
     

UIE Levels (µg/L)

Name of the
District
N
 
Median
(µg/L)
<20.0 20.0-50.0 50.0-100.0 100.0 D/N
Nellore 
93 
>200.0 
0(0.0) 
0(0.0) 
0(0.0) 
93(100.0) 
N 
Rangareddy 
107 
65.0 
1(0.9) 
23(21.5) 
48(44.9) 
35(32.7) 
D
Vishakhapatnam 
35 
>200.0 
0(0.0) 
0(0.0) 
1(2.9) 
34(97.1) 
N 
Anantpur 
98 
100.0 
1(1.0) 
7(7.1) 
38(38.8)
 52(53.1) 
N 
East Godavari 
102 
>200.0 
0(0.0) 
0(0.0) 
0(0.0) 
102(100.0) 
N 
Kurnool 
103 
130.0 
0(0.0) 
4(3.9) 
18(17.5) 
81(78.6) 
N 
Prakasam 
102 
150.0 
1(1.0) 
3(2.9) 
14(13.7) 
84(82.4) 
N 
Mehboobnagar 
100 
150.0 
2(2.0) 
5(5.0) 
19(19.0) 
74(74.0) 
N 
Cuddapah 
97 
90.0 
9(9.3) 
15(15.5) 
28(28.9) 
45(46.4)
D 
Srikakulam 
33 
>200.0 
0(0.0) 
0(0.0) 
2(6.1) 
31(93.9) 
N 
Warangal 
100 
>200.0 
1(1.0) 
0(0.0) 
7(7.0) 
92(92.0) 
N 
West Godavari 
70 
>200.0 
0(0.0) 
0(0.0) 
1(1.4) 
69(98.6) 
N 
Chitoor 
100 
100.0 
0(0.0) 
4(4.0) 
45(45.0) 
51(51.0) 
N 
Vijaynagram 
21 
>200.0 
0(0.0) 
0(0.0) 
1(4.8) 
20(95.2) 
N 
Nizamabad 
200 
150.0 
18(9.0) 
11(5.5) 
25(12.5) 
146(73.0) 
N 
Krishna 
96 
>200.0 
0(0.0) 
0(0.0) 
1(1.0) 
95(99.0) 
N 
Khammam 
100
200.0
0(0.0) 
0.(0.0)
3(3.0) 
97(97.0) 
N 
Guntur 
120 
>200.0 
0(0.0) 
0(0.0) 
2(1.7) 
118(98.3) 
N 
Adilabad 
101 
125.0 
0(0.0) 
8(7.9) 
25(24.8) 
68(67.3) 
N 
Hyderabad 
174 
150.0 
8(4.6) 
22(12.6) 
31(17.8) 
113(64.9) 
N 
Total
1952 
 
41(2.1) 
102(5.2) 
309(15.8) 
1500(76.8) 
 
 
 
[2.3-6.5]* 
[0.9-9.5]* 
[11.7-19.9]* 
[74.7-78.9]*
Figures in parenthesis denote percentages; D = Deficient iodine nutriture; N = Normal iodine nutriture; 
* 95% Confidence interval.

Constraints of the Study

The most commonly recommended methodology for assessment of iodine content of salt is the 30 cluster sampling approach. However, the present study was a rapid survey in which senior secondary school children in the age group of 11-18 years were included in the study (students from 15-30 villages attend the school). The research methodology was designed keeping in mind the budget and time constraints. The main objective of the present rapid survey was to assess the level of salt iodisation and we also took the opportunity of assessing the iodine nutriture of the population also. Hence, the urinary iodine excretion levels were estimated in children in the age group of 11-18 years. On account of used design of the study, the weighted confidence interval of the estimates could be approximate. However, in view of comparatively large sample size involved in the study, unweighted confidence interval would provide similar results. This may be evident through a narrow confidence interval observed in the study.

Discussion

The results of the present study showed that 55% of the population was consuming iodised salt with less than 5 ppm, although the percentage of population consuming salt with 15 ppm and more iodine was only 18.5%. The NFHS II survey documented that 27.4% of population consumed salt with 15 ppm of iodine. The variation between the findings of the two studies could be possibly due to difference in the sampling methodology and the method of estimation of iodine content of salt. In NFHS II survey the spot testing kit was used while in the present study the iodometric titration method was utilized for the same.

It was found that in the coastal districts of Nellore, Vishakhapatnam and Prakasam 80%, 76% and 83% of the population was consuming salt with less than 5 ppm of iodine, respectively. It is a well-known fact in areas where salt is produced locally, a high percentage of population consumes non iodized salt due to traditional reasons.

In the present study, majority of the districts (17/23) more than 60% of the population was consuming iodized salt. This was also reflected as adequate iodine nutriture (UIE level more than 100 µg/L) in all the districts except Rangareddy and Cuddapah. The study revealed the success of the salt iodisation program in districts which were earlier found endemic to iodine deficiency like Srikakulam, Vijaynagram, Visakha-patnam, Godavari, Khammam, Adilabad and Warrangal. These districts were found to have adequate iodine nutriture in the present survey as reflected by median UIE level of more than 100 µg/L. The study findings indicate a need of further strengthening the efforts for salt iodisation in Andhra Pradesh by creating an awareness amongst the salt producers, traders and beneficiaries about the health consequences of iodine deficiency.

Acknowledgement

We would like to thank the Salt Commissioner, Government of India for providing the financial and technical support for conducting the survey. We are also thankful to all the faculty members of various medical colleges in Andhra Pradesh for their most valuable support in implementation of the study.

Contributors: UK coordinated the study, helped in implementation and drafted the paper, he will act as guarantor. PS and PP helped in estimations, data analysis and coordinating.

Funding: UNICEF India Country Office, New Delhi.

Competing interest: None.

Key Messages


• Higher percentage of population was consuming salt with less than 5 ppm of iodine in the coastal districts of Andhra Pradesh.

• All the districts had adequate iodine nutriture (UIE levels more than 100 µg/L) except Rangareddy and Cuddapah.

 

 References


1. Indicators for assessing iodine deficiency disorders and their control through salt iodisa- tion. WHO / UNICEF / IDD. World Health Organisation, Geneva, 1994; pp 12-16.

2. Tiwari BK, Kundu AK, Bansal RD. National iodine deficiency disorders control programe in India. Indian J Pub Health 1995; 39: 151- 156.

3. Kapil U. Progress made in elimination of iodine deficiency disorders and possible impact of lifting ban on the sale of non-iodized salt. Hospital Admin 2000; 12: 33-41.

4. NFHS (2000) India 1998-1999- National Family Health Survey-2 (NFHS-2). Nutrition and the prevalence of anemia. International Institute for Population Sciences, Mumbai, 2000: 277.

5. Karmarkar MG, Pandav C, Krishnamachari KAVR. Principle and procedure for iodine estimation: A laboratory manual. New Delhi, Indian Council of Medical Research, 1986; pp 1-3.

6. Dunn JT, Crutchfield HE, Gutekunst R, Dunn D. Methods for measuring iodine in urine. A joint publication of WHO / UNICEF / ICCDD 1993; pp 18-23.

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