Iodine Intake - a National Survey - Assignment Example

?Iodine Intake: A National Survey Assessment Review Iodine is one of the essential trace elements needed for normal growth and development. It was studied to be an integral component of the thyroid hormone, thyroxine or T4 as well as the tri-iodothyronine or T3. Theses thyroid hormones are required for normal growth and development and body cell metabolism. Lack of iodine intake can result to iodine deficiency disorders such as hypothyroidism as well as impaired mental and physical development and many more metabolic related diseases (1). According to the Australian Academy of Science, studies have revealed that over the last decade approximately 60 % of the Australian population was found to have mild-to-moderate iodine deficiency in all groups tested (2). The reason why the Australian government funded national survey to target nutritional deficiency that covers iodine and other nutrient intake known as the Australian National Children's Nutrition and Physical Activity Survey or the children’s survey. The 2007 Australian National Children's Nutrition and Physical Activity Survey The children’s survey was done to find out the current national status of Australian children’s weight, dietary intake and activity for the purpose of evaluating the national nutritional adequacy in children. The survey measured dietary intake of food, beverages and supplements by using a 24 hour dietary recall (3). The survey has chosen participants by using a random sampling method using a quota sampling scheme by postcodes and second by Random Digit Dialing of telephone numbers (4). Children were selected to have equal distribution of samples all over Australia without consideration to factors such as neither economic status nor ethnicity. The sample of 1000 children for a corresponding age group, of which is equally divided from boys and girls, was taken from randomized families with eligible children aged 2-16 with a totality of 4, 487 (5). The sampling was made to reflect the total population of Australia but the selection method has excluded other areas such as those in very remote areas and other having little population that result of the survey cannot totally reflect the whole of Australia (4). Data collection from the acquired sample was made via a face-to-face interview (CATI) in the participant’s home followed up by a subsequent telephone interview (CAPI) conducted 7-21 days after (5). Data collection was made using a three-pass 24-hour recall methodology that ensures that recall of food intake and the estimates are properly recorded taking also into consideration the time, place and the brand of the food taken (4). Although all interviewers were trained in conducting a 24-hour recall the question of validity of the data collected will depend on how well the recall was conducted because bias will result in errors of unrecalled food and improper estimation that will falsify the calculation (5). The 3 pass 24 hour recall method is a good strategy to have proper recall by providing 3 stages that eliminates the chances of error (4). The validity of the use of this method can be reflected in some studies made available in various per-reviewed journals such as in South Africa and US (5) Iodine Nutrient Reference Values Nutrient measurement for iodine was made only in comparison with food guidelines and dietary recommendation against the estimate of what was taken according to the CAPI and CATI data (6) thus the survey only covers the estimate of the prevalence of inadequate nutrient intake unlike if done with biomarkers such as urine iodine levels. Assessing intake in the food children eat is an important factor to address deficiency. By comparing the estimated value of foods and nutrients taken against the researched standards for age group it can be said if the right values are met on a daily basis. The Estimated Average Requirement is one example of comparison which is the average daily nutrient intake level that is estimated to meet the nutrient requirements of half of the children in each of the age and gender groups. The percentage of EAR provides an estimate on the adequacy of nutrient intake (7). The EAR for iodine is higher than 50% in the 14-16 age group of the study with 95% for boys, 75% for girls and 85% combined which means that the potentiality of inadequate intake fro iodine is low. With this data at hand it can be said that the degree of inadequacy for iodine intake for boys, girls and both boys and girls aged 14-16 is very low in Australia. Meanwhile, if EAR could not be used because of limited scientific evidence, Adequate Intake is used instead. AI is defined as the average daily nutrient intake levels based on observed approximations of estimates by a group of assumed healthy people (7). But unlike the EAR, the proportion of children having intakes less than the AI does not estimate the prevalence of potentially inadequate intakes. Moreover the average daily dietary intake level that is sufficient to meet the nutrient requirements of almost all healthy individuals in a particular life stage and gender group is known as the Recommended Daily Intake. According to Nutrient Reference Values for Australia RDI for age 14-16 is 150 micrograms per day for both boys and girls, which is a lot higher than the EAR which is just 95%. If the RDI will be used for comparison it will show that girls form the study group aged 14-16 is not meeting the RDI as well as the gender combined which fall a little short at mean intake of 147.5 mcg per day. The differences in the result of the RDI and EAR could be from the differences of their population. EAR is set in the standards for almost all of the population while the EAR is on the half mark (1). The table below summarizes the result of the survey compared against different standards: Table 1. Summary of Values for Iodine Intake for boys and girls aged 14-16 compared to the standard values (1) Population sample age 14-16 years old Iodine intake (mcg/day) EAR (mcg/day) % Meeting Iodine EAR Iodine RDI (mcg/day) Iodine UL (mcg/day) Boys 174.8 mcg 95mcg/d 95% 150 mcg/d 900 mcg/d Girls 118.8 mcg 95mcg/d 74% 150 mcg/d 900 mcg/d Total( Boys and Girls) 147.5 mcg 95mcg/d 85% 150 mcg/d 900 mcg/d From these data it can be said that the population studied have meets the standards according to the EAR but have a little deficiency in the intake of iodine for girls and for the total while the upper limit was not reached at all that conveys too much intake (1). Iodine Deficiency Iodine is said to be an important factor in the development of a child as well as in cognition. Several studies have proved that deficiency in iodine in children can greatly affect cognition of a child thus compromising the overall school performance. One study notes that intellectual function and motor skills in children from iron-deficient areas are decreased. A metal-analysis that included 2214 participants of mainly children was made by measuring their IQ. The result shows that the IQs of non-iodine-deficient groups were on the average of 13.5 IQ points above the deficient group. Similar studies as such prove that iodine is an important factor in the development of a person’s cognition skills from infanthood to adulthood and that iodine treatment in areas of low iodine intake can still save the cognition problems (8). This statement was proved by a study entitled ‘Iodine supplementation improves the cognition in mildly iodine-deficient children,’ which was done as a randomized, placebo-controlled, double-blind trial conducted in 84 children in New Zealand. The result showed that iodine supplementation significantly improved the scores of a cognitive tests compared to the groups given placebo. This trial also has proven that even mild iodine deficiency can greatly affect a child from his full cognitive potential (9). In contradiction, one author suggests the further validity of these studies because of the inconsistencies of the results and did not reach statistical significance. However the link between cognitive development and prenatal iodine deficiency is not a query and should be given emphasis due to the effect it has on a newborn. Public health methods are now heading clear path in giving information to the world on the importance of iodine as a micronutrient and how to combat insufficiency by simple ways of iodized salt or iodized oil supplementation (10). Thus the Children’s survey is an effective way to combat nutritional deficiencies not just for iodine but for all of the other nutrients needed by a person to grow. By way of this survey the nutritional status of children will be directly addressed and thus will help them in developing their full potential physically and intellectually. References 1. National Health and Medical Research Council. Nutrient Reference Values for Australia and New Zealand- Iodine. Commonwealth of Australia. 2006 2. Australian Academy of Science. National Committee for Nutrition. Iodine Deficiency. Commonwealth of Australia. 2012 3. Department of Health and Aging, Department of Agriculture and Fisheries. Australian Food and Grocery Council. 2007 Australian National Children's Nutrition and Physical Activity Survey - Introduction. Canberra: Commonwealth of Australia; 2008. 4. Department of Health and Aging, Department of Agriculture and Fisheries. Australian Food and Grocery Council. 2007 Australian National Children's Nutrition and Physical Activity Survey – User Guide. Canberra: Commonwealth of Australia; 2008. 5. Rakin et al. Dietary Assessment Methodology for Adolescents: A review of reproducibility and validation studies. S Afr J Clin Nutr. 2010; 23(2);65-74 6. Department of Health and Aging, Department of Agriculture and Fisheries. Australian Food and Grocery Council. 2007 Australian National Children's Nutrition and Physical Activity Survey - Methodology. Canberra: Commonwealth of Australia; 2008. 7. Department of Health and Aging, Department of Agriculture and Fisheries. Australian Food and Grocery Council. 2007 Australian National Children's Nutrition and Physical Activity Survey – Food and Nutrients. Canberra: Commonwealth of Australia; 2008. 8. Zimmerman M. Iodine deficiency. The Endocrine Society. ER. 2009;30(4),376-408 9. Gordon et al. Iodine Supplementation improves cognition in mildly iodine-deficient children. Am J Clin Nutr. 2009:1264-1271 10. Black M. Micronutrient Deficiencies and Cognitive Functioning. American Society of Nutritional Sciences. JN.2003;3927S- 3931S Read More