Results of testing household salt used for cooking and/or as table salt.  For accurate testing, household samples of salt should be sent to laboratories for titration testing that can determine concentration levels (WHO, 2001). Rapid test kits have been designed for screening and can indicate if iodine is present in a sample, but do not give a reliable measure of concentration.  The rapid test kits lack the necessary sensitivity and specificity for calculating this indicator (Gorstein, et al., 2007). Household salt iodine levels can be categorized as adequate or inadequate and, where found, as excessive.  Household surveys also can collect data on brand names, dates of expiration, and the presence or absence of iodization labeling (ACC/SCN, 2007). Where available, data can be disaggregated by geographic/ecological zone and relevant socioeconomic and demographic factors such as education, income, and urban/rural residence

Data Source(s):

Population-based household surveys; the testing of households using iodized salt is part of the core questionnaire in the DHS and UNICEF-MICS.

Purpose:

This indicator serves as a proxy measure for the number of women who may be receiving adequate amounts of iodine.  Iodine deficiency disorders (IDD) are prevalent throughout the world and an estimated two billion people have inadequate iodine intake (Gorstein et al., 2007).  The most at-risk populations for low iodine intake live in remote inland areas where no marine foods are eaten.  IDD interventions often focus on women of reproductive age because of their increased need for iodine during pregnancy.  Iodine deficiency in pregnancy can cause extreme and irreversible mental and physical retardation known as cretinism.  Even milder, subclinical deficiencies can impair fetal motor and mental development and are associated with miscarriage, fetal growth restriction, stillbirth (ACC/SCN, 2007; Black et al., 2008; WHO, 2010).  Mild deficiency among children and adults is very common and can cause loss of learning ability and goiter (an enlargement of the thyroid gland).  Iodine deficiency alone was found to lower mean IQ scores by 13.5 points (Bleichrodt and Born, 1994).  For pregnant women with severe deficiencies, iodine supplementation by the second trimester can improve neurological and cognitive development of the infant (Black et al., 2008).  This indicator relates to achieving Millennium Development Goals: #4. Reduce child mortality; and #5. Improve maternal health.

Issue(s):

In measuring household availability of iodized salt for women in the sample, the indicator does not reflect the women’s actual intake of iodine or their physiologic iodine status.  Households’ salt supplies may be from varying sources, some of which are iodized and others not, or the salt processing facilities may not be consistent in the levels of iodine added.  For women with severe IDD, household availability of iodized salt may not provide sufficient iodine needed during pregnancy and supplementation may be needed.

References:

ACC/SCN, 2007, ‘Universal Salt Iodization,’ SCN News; No. 35, Geneva: WHO.