Critical evaluation of the results for iodine intake collected as part of the 2007 Australian National Children’s Nutrition and Physical Activity Survey (CNPAS).
The sample for study was chosen by postcode and families within selected postcodes were selected using Random Digit Dialing (RDD) of mobile numbers. The study was designed to focus on collecting data for representative trials of children staying in urban and not those of indigenous background. This implies that, postcodes leading to remote or local backgrounds were removed from the original representative group. Suitable families who had children between 2-18 years old were recognized and requested to take part in the study. A ‘study child’ was picked from a selected family. An agreed quota consisted of 500 boys and girls between the ages of 14-18 years. An addition of 400 children was also drawn from South Australia. In total, 4,487 children participated in the whole study.
The sampling method adopted ensured that not less than 500 boys and girls across Australia between 2-3 years, 4-8 years, 9-13 years and 14-16 years were covered in the study. This allowed for comparison of figures on intake and observations were made. The south Australian department of health made its input towards a jab sample (n=400) in Australian children.
Data collection was partly done through face to face interviews at the residence of participants (CAPI) and a follow up telephone interview (CATI) carried out between one to three weeks after the CAPI.
Consumption and level of activity differ on the basis of day of the week. For example, level of activity varies from Monday to Friday and non school days or weekends and week days. Therefore, CAPI and CATI were collected on different days to ensure that data collected was representative of all the days.
Issues of methodology
The RDD technique is commendable because it saves time and is an effective move towards engaging samples for survey. Previously, the method had been used to create population samples for health studies.
It is estimated that over 95 per cent of Australian families have a land line telephone though some families have replaced the land line with mobile telephone numbers so that they can easily move to different geographical locations. This is an advantage for RDD because being a silent technique, newly listed and unlisted numbers can be included by chance (Yalcin 294).
Iodine Nutrient Reference Values
The following table shows a summary of the relationship among Estimated Average Requirement (EAR), Recommended Daily Intake (RDI) and Upper Level of Intake (U L) of iodine in children with ages between 14-16 years old.
Iodine in take in children below the age of 18 years old.
An NRV was also established for the purpose of planning and evaluating diets of families in New Zealand and Australia. NRVs are then compared to standard dietary intake. Information on common dietary intake was obtained from beverages and food, without including supplements. The data was then compared to EAR or A L (Lumberd 120).
The following observations can be made from the tables;
It can be observed that iodine intake increases as the children grow up. For example, children between the ages 2-3 consumed about 125.6 mcg of iodine while those between the ages of 14-16 consumed about 147.5mcg of iodine. The differences between the genders are higher in older children i.e. those between ages 14-16 (Kester 123).
Children between 14-16 years have a higher EAR because they are at their peak in adolescent and require more iodine compounds to facilitate the growth of muscles, broadening of the chest or hips and other secondary changes on their bodies. Another explanation for the differences in the EAR lies in the fact that children between the ages of 14-16 years are more physically active than their younger counterparts (Hess 128).
Upper level of intake (UL) refers to the highest amounts of iodine required daily for children between the ages of 14-16 years. There was no major difference between the UL figures in children below the age of 16 years.
Health implications of iodine
This is a very informative article because it manages to evaluate the importance of iodine in children below the age of 16 years of both sexes. The article further makes an effort to explain the differences in the amount of consumption as children grow old.
The article appreciates that although iodine is needed by the body in small amounts, it is a very important element required to stimulate basic metabolic functions in the body. Firstly, iodine is required by children for proper mental development. A deficit of iodine in the bodies of fetuses and young children could lead to severe growth and development problems. Among other symptoms, such children will have stunted growth, lower IQ and retardation.
The article further recognizes the importance of iodine as a raw material for the manufacture of thyroid hormones (Thyroid Stimulating Hormone-TSH). This is a hormone required by the body to stimulate growth and maintain a healthy metabolic and nervous system. When there is a deficit of iodine in the body, the thyroid gland starts performing its functions at a slower rate. The article also examines amounts of iodine required by children of all ages as well as the effects of a deficit in children from different social economic background. Low amount of iodine in the diet leads to the swelling of the thyroid gland, a condition called struma. However, struma is a rare disease because the common table salt comes with a little iodide compounds (Frieseman and Visser 759).
The article emphasizes the fact that as much as iodine is a trace element, its absence in the body can lead to severe consequences.
The second journal article evaluates secondary health implications for iodine not only in the body, but also on the environment. For example, it acknowledges that major skin cleansers and medicine for treating wounds also contain iodine. Iodine is also known for its radioactive functions in the body by preventing fibrocystic and mammary dysplasia in humans. It examines studies carried out on animals, more so, the rats which show that they also develop the fibrocystic disease. More studies on human beings show that women with iodine deficiency have a higher risk of getting sick with fibrocystic disease. The study further claimed that iodine concentration in women affects their menstrual cycle. Therefore, Iodine in the body prevents fibrocystic disease (Hess 121).
The article further evaluates how amounts of iodine in the urine of pregnant women can be used by doctors to prescribe medicine. For example, pregnant mothers who show less than 100mcg/l indicate that the woman does not have sufficient iodine in the body. The doctor can then advise the patient to consume more of iodide compounds. However, levels of iodine in the blood are usually constant and only when they drop lower than 20mcg/l, then the doctor can recommend treatment.
The article goes ahead to demonstrate how common salt serves as the main supplier of iodine in the human body. The common table salt is the main supplier of iodine in human beings. In water supply industries, iodine is used as a component of water sanitization. Finally, the article goes ahead to connect iodine with fibrocystic disease in rats and how the element prevents the disease in women.
Journal article three is also very informative because it acknowledges the importance of macronutrients and the environment as sources of iodine.
For instance, the journal article agrees that aquatic foods and bread have an element of iodine. In addition, aquatic organisms have a higher concentration of iodine in their organs.
Natural iodine is found in the soil, water and air. However, large water bodies are the main suppliers of iodine, according to this article. A larger percentage of evaporated iodine is deposited on land to continue with the bicycle (Caldwell 29).
According to the article, ores of glutarate and iodargyte are key sources of iodine in industries. The article estimates that the worldwide production of iodine goes above 13,000 tonnes per twelve months. Japan and Chile are the main manufacturers of iodine, USA and Russia manufacture iodine, but on small scale. The industrial raw material for the manufacture of iodine includes oil brines and natural brines.
However, more research needs to be done to find out if tap water can be used to supply iodine to the body and the best mode of transmission.
References
Caldwell, Makhmudov. “Iodine Status of the U.S.Population, National Health and Nutrition Examination Survey; 2005-2006 and 2007-2008.” John Hopkins publication 32.5 (2011): 23-36. Print.
Friesema, Jansen and Milici Visser. “Thyroid hormone transporters in health and disease.” Thyroid 15.8 (2008): 757–768. Print.
Hess, Simon. “The impact of common micronutrient deficiencies on iodine and thyroid metabolism: the evidence from human studies.” Best Practices Metab Journal 24.1(2011): 117-132. Print.
Kester, Martinez de Mena. “Iodothyronine levels in the human developing brain: major regulatory roles of iodothyronine deiodinases in different areas.” Clin Endocrinol Metab 89.7 (2005): 117–128. Print.
Lumberd, Partrick. “Iodine: deficiency and therapeutic considerations.” The Alter Medical Journal. 13.2 (2009): 116-127. Print.
Yalcin, Ozan. “Detailed investigation of the relationship between the inferior laryngeal nerve including laryngeal branches and ligament of Berry.” Journal of the American College of Surgeons 202.2 (2006): 291–296.Print.