Thyroid Research and Practice

: 2016  |  Volume : 13  |  Issue : 2  |  Page : 49--51

Iodized salt in India: Insights from National Family Health Survey-4

Arun Kumar1, Sanjay Kalra2, AG Unnikrishnan3,  
1 Department of Community Medicine, Shaheed Hasan Khan Mewati Government Medical College, Nalhar, Mewat, India
2 Department of Endocrinology, Bharti Hospital, Karnal, Haryana, India
3 Chellaram Diabetes Institute, Pune, Maharashtra, India

Correspondence Address:
Dr. Sanjay Kalra
Department of Endocrinology, Bharti Hospital, Karnal, Haryana

How to cite this article:
Kumar A, Kalra S, Unnikrishnan A G. Iodized salt in India: Insights from National Family Health Survey-4.Thyroid Res Pract 2016;13:49-51

How to cite this URL:
Kumar A, Kalra S, Unnikrishnan A G. Iodized salt in India: Insights from National Family Health Survey-4. Thyroid Res Pract [serial online] 2016 [cited 2022 Jul 4 ];13:49-51
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Full Text

The importance of iodine for thyroid health, and the role of salt iodization in achieving this, are well known.[1] In spite of multiple legislation, use of iodized salt is still not widely accepted in India.[2] Multiple reasons exist for this. While availability is usually not a challenge, cultural beliefs and taste often lead to use of noniodized salt.

The recently conducted National Family Health Survey (NFHS)-4 reports on the usage of iodized salt in 15 states.[3] The percentage of all households which use iodized salt varies from 81.6% in Andhra Pradesh (AP) to 99.6% in Sikkim. While most states report >90% usage of iodized salt, the outliers include AP (81.6%), Tamil Nadu (82.8%), and Karnataka (86.8%). Other southern states such as Telangana (95.8%) and Puducherry (92.7%), however, report much higher rates of iodized salt usage. Smaller states and union territories, too, including Sikkim (99.6%), Andaman and Nicobar Islands (99.5%), Meghalaya (99.1%), and Tripura (99.1%), enjoy near universal iodized salt consumption [Table 1].{Table 1}

A focused analysis of the three states with low usage of iodized salt shows heterogeneity in iodized salt use across different districts.[4] In AP, for example, prevalence of iodized salt use ranges from 69.1% in Vizianagaram to 90.4% in Visakhapatnam (97.9% in urban Visakhapatnam). In Karnataka, only 66.4% households of Chikkaballapura (60.5% of rural Chikkaballapura) use iodized salt while 96.3% households in Belgaum do the same. Tamil Nadu usage varies from 54.9% usage in Tirunelveli (44.7% in the rural households) to 96.4% in Chennai.

Further analysis of the districts with low iodized salt use reveals lack of geographical contiguity. In AP, Vizianagaram, YSR (Cuddapah), Kurnool, Prakasam, and Anantapur have <80% iodization coverage. While Cuddapah, Anantapur, and Kurnool are located in the same geographical belt, Vizianagaram (the lowest iodized salt using district) is located next to Visakhapatnam (the highest user of iodized salt). In Karnataka, Chikkaballapura, Dakshina Kannada, Chitradurga, Shimoga, Gadag, and Bellary report similar coverage. These districts are located across all zones of the state. Notably, Chikkaballapura and Bellary share borders with AP. The status is similar to the Tamil Nadu districts of Tirunelveli, Theni, Tiruppur, Virudhunagar, Ariyalur, Sivaganga, Ramanathapuram, Thoothukudi, Tiruvannamalai, and Cuddalore, all of which have <75% households using iodized salt. These districts are scattered all over the state. There is a clustering of districts with high iodized salt usage in the northeastern part of Tamil Nadu namely Chennai, Kanchipuram, and Vellore. The nearby union territory (UT) of Puducherry reports near universal use of iodized salt as well. Another district located far off from these states, which reports very low usage of iodized salt, is Mewat in Haryana.

The reasons for such discrepancy need to be probed. Lack of availability, accessibility, and/or affordability may contribute to poor usage of any commodity. This does not seem to be the case for iodized salt, however. Factors such as dietary habits and taste preferences may lead to preferential use of noniodized salt.[5] This too seems unlikely as cooking practices do not differ markedly within the various states being discussed. Relatively less requirement of iodine in coastal areas can be cited as an excuse for low market penetration of iodized salt in the three states, all of which have long coastlines. However, most of the districts with extremely low iodized salt usage are located inland and need iodine supplementation.

The most plausible reason for low and variable use of iodized salt may be lack of awareness and knowledge about the importance of iodization. Public education about the risks of iodine deficiency, benefits of optimum iodization, need for external supplementation, and importance of iodized salt may be suboptimal in certain areas. However, when the state-/UT-wise percentage scores of iodized salt consumption (NFHS-4) were compared with the percentage scores of total (Census 2011),[6] male, and female literacy rates (NFHS-4), they were found to be statistically nonsignificant with Kendall's tau b correlation coefficient values of 0.265 (P = 0.188); 0.038 (P = 0.843); and 0.268 (P = 0.165), respectively [Figure 1].{Figure 1}

The available iodized salt consumption percentages in districts were further analyzed. Assuming the percentage figures for consumption of iodized salt in various districts as the respective scores, Shapiro–Wilk test was applied to assess the normality of distribution. The results showed that the scores were normally distributed in both urban and rural areas (urban: W (18) =0.938, P = 0.271; rural: W (18) =0.919, P = 0.123). The assumption of homogeneity of the variances was also found to be true with the help of Levene's test (F (1, 34) =1.346, P = 0.254). t-test results showed that there was significant difference in the iodized salt consumption scores between rural and urban areas of the selected districts with lowest consumption of iodized salt (P < 0.05). There was no significant difference in consumption of iodized salt in these districts between the various states (Kruskal–Wallis test, i.e., H (3) =6.938, P = 0.074) [Table 2].{Table 2}

The challenge of nonuniversal usage of iodized salt can be corrected in through a sustained community education program involving all stakeholders. Endocrinologists, community health specialists, and nutritionists must take the lead in planning, executing, and monitoring this plan. NFHS-4 has helped in mapping the use of iodized salt in India. If its findings are able to spur action on the ground, it will be a major push for endocrine health in general and thyroid health in particular.


1Kalra S, Unnikrishnan AG, Pandit K. Iodine and the renaissance: Will history turn full cycle? Indian J Endocrinol Metab 2014;18:750-2.
2Biradar MK, Manjunath M, Harish BR. Prevalence of iodine deficiency disorders among 6 to 12 years school children of Ramanagara district, Karnataka, India. Int J Community Med Public Health 2016;3:166-9.
3State Fact Sheets. Available from: [Last accessed on 2016 Mar 18].
4District Fact Sheets. Available from: [Last accessed on 2016 Mar 18].
5Kalra S, Kalra B, Sawhney K. Usage of non-iodized salt in North West India. Thyroid Res Pract 2013;10:12.
6Data on Education. Available from: [Last accessed on 2016 Mar 18].