Iodine Deficiency and Mental Performance: A Review

  • Zaleha Md Isa Universiti Kebangsaan Malaysia
Keywords: Iodine deficiency - Mental performance - Intelligence.


IntroductionIodine deficiency disorders (IDD) is responsible for a lot of adverse health effects and it is one of the most common causes of preventable mental impairment. Impaired cognitive function is an outcome of impaired neurodevelopment process during early pregnancy due to iodine deficiency.MethodsA few cross-sectional studies found differences in mental performance between areas with high iodine found naturally in the environment (well water) and those with low iodine level, but other studies showed otherwise.ResultsIntervention studies with iodine also give variety of results ranging from significant improvement of mental performance to non-significant findings.ConclusionsMalaysia faces with challenges in iodine supplementation among the population but it can be dealt with effectively if the programme is well executed and monitored. 


Benoist Bd, McLean E, Andersson M, Rogers L. Iodine Deficiency in 2007: Global Progress Since 2003. Food Nutrition Bulletin. 2008. 29(3):195.

Kotwal A, Priya R, Qadeer I. Goiter and other iodine deficiency disorders: A systematic review of epidemiological studies to deconstruct the complex web. Arch Med Res. 2007 Jan; 38(1):1-14.

Andersson M, de Benoist B, Rogers L. Epidemiology of iodine deficiency: Salt iodisation and iodine status. Best practice & research Clinical endocrinology & metabolism. 2010 Feb; 24(1):1-11.

Pineda-Lucatero A, Avila-Jimenez L, Ramos-Hernandez RI, Magos C, Martinez H. Iodine deficiency and its association with intelligence quotient in schoolchildren from Colima, Mexico. Public health nutrition. 2008 Jul; 11(7):690-8.

Zimmermann MB. Iodine deficiency. Endocr Rev. 2009 Jun; 30(4):376-408.

Soldin OP. Controversies in urinary iodine determinations. Clin Biochem. 2002; Nov; 35(8):575-9.

Zimmermann MB. Iodine requirements and the risks and benefits of correcting iodine deficiency in populations. Journal of trace elements in medicine and biology: organ of the Society for Minerals and Trace Elements. 2008; 22(2): 81-92.

Andersson M, Benoist Bd, Darnton-Hill I, Delange F. Iodine deficiency in Europe: a continuing public health problem. World Health Organization. 2007.

Morreale de Escobar, Susana A, Pere B, Obregon MJ, del Rey FE. The Changing Role of Maternal Thyroid Hormone in Fetal Brain Development. Seminars In Perinatology. 2008; 32: 380-6.

Melse-Boonstra A, Gowachirapant S, Jaiswal N, Winichagoon P, Srinivasan K, Zimmermann MB. Iodine supplementation in pregnancy and its effect on child cognition. Journal of trace elements in medicine and biology: organ of the Society for Minerals and Trace Elements. 2012 Jun; 26(2-3):134-6.

Costeira MJ, Oliveira P, Santos NC, Ares S, Saenz-Rico B, de Escobar GM, et al. Psychomotor development of children from an iodine-deficient region. The Journal of pediatrics. 2011 Sep; 159(3): 447-53.

Melse-Boonstra A, Jaiswal N. Iodine deficiency in pregnancy, infancy and childhood and its consequences for brain development. Best practice & research Clinical endocrinology & metabolism. 2010 Feb; 24(1): 29-38.

Dugbartey AT. 1998. Neurocognitive aspects of hypothyroidism. Arch Intern Med. 1998 Jul 13;158(13): 1413-8.

Cross C, Moriarty H, Coakley J. Prevalence of Iodine Deficiency in Infants and Young Children in Western Sydney, Australia A Cross-Sectional Analysis. . Infant, Child, & Adolescent Nutrition. 2010; 2(5): 4.

Zaleha MI, Hayaati ARN, Rizam ARM, Jamaluddin M, Osman A. Micronutrients and its correlation with mental performance among the schoolchildren in Bario, Sarawak. Medical Journal Malaysia. 2003; 58(3): 309-19.

Huda SN, Grantham-McGregor SM, Rahman KM, Tomkins A. Biochemical hypothyroidism secondary to iodine deficiency is associated with poor school achievement and cognition in Bangladeshi children. J Nutr. 1999 May; 129(5): 980-7.

Santiago-Fernandez P, Torres-Barahona R, Muela-Martinez JA, Rojo-Martinez G, Garcia-Fuentes E, Garriga MJ, et al. Intelligence quotient and iodine intake: a cross-sectional study in children. J Clin Endocrinol Metab. 2004 Aug; 89(8): 3851-7.

Zimmermann MB, Connolly K, Bozo M, Bridson J, Rohner F, Grimci L. 2006. Iodine supplementation improves cognition in iodine-deficient schoolchildren in Albania: a randomized, controlled, double-blind study. Am J Clin Nutr. 2006 Jan; 83(1): 108-14.

Zaleha MI, Osman A, Iskandar ZA, Sazali S, Ali MM, Roslan I, et al. The Supplementation of Levothyroxine Among Indigenous People in Endemic Goitre Areas: The Impact of Therapy. Asia Pacific Journal of Clinical Nutrition. 1998; 7(2): 138-50.

Zaleha MI, Osman A, Iskandar ZA, Zainuddin B, Muhammad AM, Khalid BAK. Goitre Prevalens and Mental Performance among Aborigines in Sinderut, Pahang. Sains Malaysiana. 1996; 25(2):51-8.

Huda SN, Grantham-McGregor SM, Tomkins A. Cognitive and motor functions of iodine-deficient but euthyroid children in Bangladesh do not benefit from iodized poppy seed oil (Lipiodol). J Nutr. 2001 Jan; 131(1): 72-7.

Lim K, Wong M, Nazaimoon WM, Kamaruddin NA. Prevelence of Iodine deficiency disorder amongst orang asli in Hulu Selangor, Malaysia. Medical and Health Science Journal. 2012; 11:2-6.

Nazaimoon WM, Rusidah S. Malaysia Needs Wider Coverage With Iodized Salt. IDD Newsletter [Internet]. 2010; (February 2010).

Khor GL. Micronutrient deficiency and its alleviation: The case of Malaysia. Asia Pacific Journal of Clinical Nutrition. 2002; 11:377-81.

Lim KK, Rohana DS, Nazaimoon WM. An evaluation of the effectiveness of water iodinator system to supply iodine to selected schools in Terengganu, Malaysia. Tropical Biomedicine. 2006; 23(2): 172-8.

How to Cite
Md Isa, Z. (2013). Iodine Deficiency and Mental Performance: A Review. International Journal of Public Health Research, 3(2), 312-317. Retrieved from