Despite living in an urban community, my brother and I grew up hearing stories about white ladies, elves and other aswangs roaming our neighborhood. Once, when a playmate's older sister came to fetch her brother at our house, she claimed to have seen a pair of black legs and feet "walking" in our garage as she looked through our gate's peephole. Another playmate insisted that a witch, with lumps, bumps, boils on her body, lived along our street. Of course, we did not believe this until we saw the "old hag" for ourselves.
One evening, as my brother and I were walking home from a friend's house, we caught a glimpse of an old lady in front of the house where the witch supposedly lived. She was wrinkly, had moles and warts all over her face, was stooped down and walked with a cane. But what was most creepy about her was a large mass that protruded from her neck. Upon seeing it, my brother and I made a run for it. We later found out that the old lady, aside from being nice and endearing, had goiter and that goiter was most commonly caused by iodine deficiency.
Iodine and Metabolism
Since its discovery as an element in 1811, much has been studied about the role of iodine in nutrition and bodily functions. Although often associated with goiter prevention, the inclusion of iodine in the diet is crucial in ensuring the body's overall normal growth and development. This is because iodine is responsible for many physiological processes in the body. If left unchecked, iodine deficiency can have serious effects on organ development and function.
Up to 60 to 80 percent of iodine, which is utilized as iodide in the body, is stored in the thyroid gland, which secretes hormones that control the body's metabolic processes and consequently, its metabolic rate. The thyroid hormones thyroxine (T4) and triiodothyronine (T3), for example, affect heart rate, blood pressure, temperature, protein synthesis and weight loss or gain.
Iodine and Brain Development
Iodine stored in the thyroid gland is chiefly used to synthesize thyroid hormones. These hormones are critical for brain development, especially during fetal and postnatal life. An insufficient amount of iodine during pregnancy results in irreversible damage to the fetal brain, unless the low levels of iodine are detected early on in gestation and interventions are introduced to address them. Damage to the brain can result in mental retardation or a significant drop in intelligence quotient.
Symptoms of Iodine Deficiency
Goiter is the medical condition primarily associated with iodine deficiency. A goiter or the enlargement of the thyroid gland develops in an attempt by the thyroid to capture more iodine in the blood by increasing the gland's surface area. Aside from the development of goiter, manifestations of iodine deficiency may include poor brain function or perception, depression, abnormal weight gain or loss, decreased fertility, coarse skin, constipation and fatigue, especially during an infant or child's critical growth years. The World Health Organization reports that iodine deficiency is the leading cause of mental retardation, especially among developing countries. Iodine deficiency can eventually lead to hypothyroidism as well.
Dietary Sources of Iodine
Basically, iodine deficiency can be addressed by eating food rich in the element. Ninety percent of dietary iodine can be sourced from food, the remaining 10 percent from drinking water. Marine plants and animals are the main sources of iodine in the diet. Among the food items that can be easily obtained from the market and are a good source of dietary iodine are salmon, halibut, sea bass, shrimps, lobsters, oysters, clams and seaweeds such as kelp. Canned seafood, such as sardines and tuna, are also excellent and convenient sources of the trace element. Vegetables such as garlic, lima beans, chard, spinach, squash, soybeans, eggs and dairy products are only some of the terrestrial sources of the dietary nutrient.
To prevent deficiency-related conditions, a daily recommended dietary allowance for iodine, according to age, has been established. They are the following:
0-6 months: 110 mcg
7-12 months: 130 mcg
1-8 years: 90 mcg
Boys 9-13 years: 120 mcg
Girls 9-13 years: 120 mcg
Boys 14-18 years: 150 mcg
Girls 14-18 years: 150 mcg
Men 19 years and older: 150 mcg
Women 19 years and older: 150 mcg
Pregnant women 14 years and older: 220 mcg
Lactating women 14 years and older: 290 mcg
Iodized Salt
In developing countries or those which do not have extensive aquatic resources, getting the sufficient amount of iodine used to be very, very difficult. As a result, the number of goiter and mental retardation cases in newborns significantly increased. However, with the introduction of iodized salt in these countries, the cases of iodine deficiency-related conditions have begun to decrease. The use of iodized salt as an inexpensive source of one's daily iodine requirement is highly encouraged and promoted by both the government and private sector in these countries.
One-fourth teaspoon of iodized salt contains about 95 micrograms of iodine. On the other hand, people with restricted salt diets can source their iodine from vitamin supplements, which usually contain 150 micrograms of the mineral.
Other Iodine Benefits
Aside from regulating thyroid function and the metabolic processes associated with it, iodine also plays a key role in the following physiological functions:
ï‚· Optimum utilization of calories - Iodine promotes the full utilization of calories, which guarantees maximum energy levels for the body and prevents the accumulation of these calories as excess fat;
ï‚· Growth of healthy hair, teeth and nails - The element promotes the efficient assimilation of calcium, silicon and other minerals in the body, thereby promoting healthy and glowing skin and hair growth. It is also said to minimize falling hair.
ï‚· Development of the reproductive system - Sufficient amounts of iodine during pregnancy assure the normal growth and maturity of a fetus' reproductive organs. Iodine also prevents still births or neuro-cognitive conditions like cretinism, or severely stunted physical and mental growth, in babies.
ï‚· Prevention of fibrocystic disease - When used in therapy, iodine can significantly reduce symptoms of fibrosis, such as fibrocystic breast disease.
ï‚· Apoptosis - Iodine-programmed cell death or apoptosis guarantees the differentiation of tissues in the embryo and thus the formation of new organs. It also helps in the removal of malignant or diseased cells which may otherwise harm the body. Studies have also shown that cancer cells shrink when exposed to iodine-based therapies. In patients with hyperthyroidism, one of the alternative treatments is to insert a radioactive iodine needle in the enlarged thyroid gland to bring it back to normal size.
ï‚· Toxin removal - Iodine helps in the removal of toxins such as fluoride, heavy metals such as mercury and lead, and other biochemical toxins that may be present in the blood. Harmful bacteria are also destroyed, especially in the stomach. (In fact, iodine-based gargles, wound-cleaning solutions and feminine washes have been made available in the market because of iodine's anti-viral, bacterial and fungal properties.) As a result, the immune system is strengthened.
Iodine Overdose and Drug Interactions
As with anything, too much of a good thing is bad. Taking too much iodine, i.e., more than 30 times the recommended allowance, can be dangerous to people suffering from kidney ailments or tuberculosis. It may also cause thyroid papillary cancer. As such, the iodine intake of pregnant or lactating women is monitored, to prevent passing lethal doses of the element to infants. Symptoms of iodine overdose include mouth sores, experiencing a metallic taste in the mouth, swollen salivary glands, diarrhea, vomiting, headache and rashes.
Fortunately, cases of iodine overdose are rare, even at levels 10 to 20 times the recommended daily allowance. However, in an attempt to prevent the symptoms of iodine toxicity, the US Institute of Medicine of the National Academies established the following tolerable upper intake levels (TUL) for iodine:
1-3 years: 900 mcg
4-8 years: 300 mcg
9-13 years: 600 mcg
14-18 years: 900 mcg
19 years and older: 1,100 mcg
Pregnant women 14-18 years: 900 mcg
Pregnant women 19 years and older: 1,100 mcg
Lactating women 14-18 years: 900 mcg
Lactating women 19 years and older: 1,100 mcg
A word of caution: persons with thyroid diseases or who experience iodine deficiency symptoms should first consult their doctors before taking iodine supplements or increasing the amount of iodized salt in the diet. Those who are taking medicine for thyroid problems and heart conditions, as well, should consult their physicians regarding drug interactions when taking dietary iodine.
In today's fast-paced world, people often take for granted even the smallest of concerns such as iodine intake. The absence of a goiter does not mean that one is already meeting the RDA for iodine. As a precaution, one should make it a point to train one's children to eat seafood or to make it a habit to use iodized salt in cooking. It wouldn't hurt to follow these simple steps that ensure a supply of iodine in the diet. As the jingle of the late 1990s campaign about the use of iodized salt promoted by the Department of Health states: "Walang bobo, walang talo, kung iodized salt ang gamit mo." ###
Sources:
http://ezinearticles.com/?The-Nutritional-Health-Benefits-of-Iodine&id=389967
http://health.learninginfo.org/iodine.htm
http://www.healthvitaminsguide.com/minerals/iodine.htm
http://www.dietbites.com/Vitamins-Minerals-Facts/Iodine-5.html
