Iodine deficiency is an important global health issue, especially for fertile and pregnant women. It may result in metabolic problems such as goiter, sometimes as an endemic goiter as well as cretinism due to untreated congenital hypothyroidism, which results in developmental delays and other health problems. Iodine is a lack of the trace element iodine, an essential nutrient in the diet. It is also a preventable cause of intellectual disability. Iodine deficiency resulting in goiter occurs in 187 million people globally as of 2010 i.e. 2.7% of the population. It resulted in 2700 deaths in 2013 up from 2100 deaths in 1990. Having considered iodine deficiency a dreaded disease, Siddha Spirituality of Swami Hardas Life System appeals to our valuable readers to get well-acquainted with it for well-being.
What does Iron deficiency Mean?
An iodine deficiency means your body can’t make enough of them, leading to hypothyroidism.
What are the Symptoms of Iodine deficiency?
Due to the lack of dietary iodine to make thyroxine, it gives rise to high levels of thyroid-stimulating hormone (TSH), which stimulates the thyroid gland to increase many biochemical processes; cellular growth and proliferation can result in the characteristic swelling or hyperplasia of the thyroid gland, or goiter. In mild iodine deficiency, levels of triiodothyronine (T3) may be elevated in the presence of low levels of levothyroxine, as the body converts more of the levothyroxine to triiodothyronine as compensation.
Public health initiatives to lower the risk of cardiovascular disease has resulted in lower discretionary salt use at the table. Additionally, there is a trend towards consuming more processed foods in western countries.
If the goiter is untreated for around five years, however, iodine supplementation or thyroxine treatment may not reduce the size of the thyroid gland because the thyroid is permanently damaged.
Congenital iodine-deficiency syndrome
It is a condition associated with iodine deficiency and goiter, commonly characterized by:
- Mental deficiency,
- Disorders of stance and gait, and
- Stunted growth due to hypothyroidism.
As a result of restricted diet, isolation, intermarriage, etc, as well as low iodine content in their food, children often had peculiar stunted bodies and retarded mental faculties, a condition later known to be associated with thyroid hormone deficiency.
While reporting recent progress towards overcoming iodine-deficiency disorders worldwide, The Lancet noted: “According to World Health Organization, in 2007, nearly 2 billion individuals had insufficient iodine intake, the third being of school age.” A conclusion was made that the single most preventable cause of intellectual disability is that of iodine deficiency.
Fibrocystic breast changes
There is preliminary evidence that iodine deficiency enhances the sensitivity of breast tissue to estrogen. In rats treated with estradiol, iodine deficiency has been shown to lead to changes similar to benign breast changes that are reversible by increased iodine in the diet. In a few studies, iodine supplementation had beneficial effects in women with fibrocystic breast changes.
Protective effects of iodine on breast cancer have been postulated from epidemiologic evidence and described in animal models. In view of the antiproliferative properties of iodine in breast tissue, molecular iodine supplementation has been suggested as an adjuvant in breast cancer therapy.
What Causes Iodine deficiency?
Our bodies do not produce iodine, so it must come from our diet. Iodine deficiency is rare in the United States, partly due to the widespread use of iodized salt. Natural sources of iodine include food from the sea and from areas where the soil is rich in iodine. Worldwide, mountainous areas and inland lowlands far from the oceans tend to have iodine-poor soil. These are the areas where iodine deficiency is most common.
What are the Risk Factors of Iodine deficiency?
Following is a list of potential risk factors that may lead to iodine deficiency:
- Low dietary iodine
- Selenium deficiency
- Exposure to radiation
- Increased intake/plasma levels of goitrogens, such as calcium
- Sex (higher occurrence in women)
- Smoking tobacco
- Alcohol (reduced prevalence in users)
- Oral contraceptives (reduced prevalence in users)
- Age (for different types of iodine deficiency at different ages)
Iodine deficiency Pathophysiology
Iodine accounts for 65% of the molecular weight of T4 and 59% of T3. There is a total of 15–20 mg of iodine in the human body, primarily concentrated in thyroid tissue and hormones. In the cells of the tissues, iodide enters directly by sodium-iodide symporter (NIS).
How Iodine deficiency is Diagnosed?
A 24-hour urine iodine collection is a useful medical test. For the standardized 24-hour test, a 50 mg iodine load is given first, and 90% of this load is expected to be recovered in the urine of the following 24 hours.
If a 24-hour urine collection is not practical, a random urine iodine-to-creatinine ratio can alternatively be used. However, the 24-hour test is found to be more reliable.
Iodine deficiency that exists can be determined through a functional iodine test. The skin is painted with an iodine solution:
- If the iodine patch disappears quickly, this is taken as a sign of iodine deficiency.
- However, no accepted norms exist on the expected time interval for the patch to disappear, and in persons with dark skin color, the disappearance of the patch may be difficult to assess.
What are the complications of Iodine deficiency?
Especially in infants and young children, complications can be serious. You can help minimize your risk of serious complications by following the treatment plan. Complications of iodine deficiency include:
- Cognitive decline and personality changes
- Congestive heart failure
- Cretinism, mental retardation, deaf-mutism, gait abnormalities, and goiter
- Goiter (enlargement of the thyroid gland in the neck)
- Menstrual irregularities
- Miscarriage or stillbirth
- Weight gain
How to treat Iodine deficiency?
Treatment is by ingestion of iodine salts, however, mild cases may be treated by:
- Using iodized salt in daily food consumption, or
- Drinking more milk, or
- Eating egg yolks, and
- Saltwater fish.
The recommended daily intake of iodine for adult women is 150–300 µg for maintenance of normal THYROID function; for men, it is somewhat less at 150 µg.
However, too high iodine intake, for example, due to overdosage of iodine supplements, can have toxic side effects. It can lead to hyperthyroidism and consequently high blood levels of thyroid hormones (hyperthyroxinemia).
In the case of extremely high single-dose iodine intake, typically a short-term suppression of thyroid function occurs. Persons with pre-existing thyroid disease, elderly persons, fetuses and neonates, and patients with other risk factors are at a higher risk of experiencing iodine-induced thyroid abnormalities.
What are Iodine rich foods?
In fact, one-third of the population is at risk of iodine deficiency, particularly those who live in areas that have only a small amount of iodine in the soil, including European countries. Iodine deficiency can lead to swelling of the thyroid gland, known as goiter, and hypothyroidism, which can cause fatigue, muscle weakness, and weight gain.
Following are the iodine-rich food sources that can help prevent a deficiency:
It is a good source of antioxidants, vitamins, and minerals, which is also low in calories. Seaweed is one of the best natural sources of iodine. However, the amount can vary significantly based on seaweed type, the region in which it grew, and its preparation.
Three popular seaweed varieties include kombu kelp, wakame, and nori.
Kombu kelp can contain up to 2,984 mcg of iodine per seaweed sheet (1 gram). This provides almost 2,000% of the recommended daily intake.
Wakame from Asia has higher amounts of iodine than wakame from Australia and New Zealand. One study found that the average amount of iodine in wakame seaweed from various parts of the world was 66 mcg per gram or 44% of the daily recommended intake.
It is a type of red seaweed. Unlike brown seaweeds, it has a much lower content of iodine. The iodine content in nori varies between 16–43 mcg per gram or about 11–29% of the daily value.
It is a versatile white fish that is delicate in texture and has a mild flavor, which is relatively low in fat and calories but offers a wide variety of minerals and nutrients, including iodine.
According to the Icelandic Food Content Database, fish low in fat have the highest iodine amounts. For instance, 3 ounces (85 grams) of cod has approximately 63–99 mcg or 42–66% of the daily recommended amount.
The amount of iodine in milk and dairy differs greatly based on the iodine content in the cattle feed and the use of iodine-containing disinfectants during milking.
A comprehensive study measured the iodine content in 18 different brands of milk sold in the Boston area. It found that all 18 brands had at least 88 mcg in 1 cup (8 ounces) of milk. Some brands even contained up to 168 mcg in one cup.
Based on these results, 1 cup of milk can provide 59–112% of the recommended daily amount of iodine.
Yogurt is also a good dairy source of iodine. One cup of plain yogurt provides approximately half of the daily recommended amount.
The amount of iodine in cheese varies depending on the type. Cottage cheese is one of the best sources of iodine. One cup of cottage cheese provides 65 mcg, while one ounce of cheddar cheese provides about 12 mcg.
The addition of iodine in table salt began in the US in the early 1920s to help decrease the occurrence of goiters, or swelling of the thyroid gland.
In the last few decades, iodine intake has decreased in the US. This is likely due to the push of major health organizations to restrict daily sodium intake to prevent or treat high blood pressure.
Nevertheless, salt only seems to raise blood pressure in salt-sensitive individuals, which is about 25% of the population.
It is low-calorie, protein-rich seafood that is a very good source of iodine. Additionally, shrimp provides key nutrients such as vitamin B12, selenium, and phosphorus. Shrimp and other seafood are good sources of iodine because they absorb some of the iodine that is naturally present in seawater.
Three ounces of shrimp contain about 35 mcg of iodine or 23% of the daily recommended intake.
Tuna is also a low-calorie, high-protein, iodine-rich food. Furthermore, it is a good source of potassium, iron, and B vitamins. It is also a good source of omega-3 fatty acids, which may lower your risk of heart disease. Fish higher in fat offer lower amounts of iodine. However, tuna is still a relatively good source of iodine, as three ounces provide 17 mcg or about 11% of the recommended daily intake.
For fewer than 100 calories, one whole egg provides a lean source of protein, healthy fats, and a wide assortment of vitamins and minerals. However, the majority of these nutrients, including iodine, come from the yolk.
Egg yolks are a good source of iodine. Yet since the content of iodine in chicken feed can vary, the amount found in eggs can also fluctuate. On average, one large egg contains 24 mcg of iodine or 16% of the daily value.
Prunes are a good vegetarian or vegan source of iodine. Five dried prunes provide 13 mcg of iodine or about 9% of the daily value.
Prunes are commonly known for helping relieve constipation. This is because of their high content of fiber and sorbitol, a type of sugar alcohol, which are high in many vitamins and nutrients, including vitamin K, vitamin A, potassium, and iron.
Because of the nutrients, prunes offer, they may help improve heart health, decrease the risk of colon cancer and even help manage weight by decreasing appetite.
Lima beans are a good source of fiber, magnesium, and folate, making them a heart-healthy choice.
They are also a relatively good vegetarian or vegan source of iodine. Due to the variation of iodine in soil, irrigation water, and fertilizers, the amount of iodine can vary in fruits and vegetables. However, on average, one cup of cooked lima bean contains 16 mcg of iodine or 10% of the daily value.
QUESTIONS & ANSWERS
Q:1 What is the meaning of Iodine deficiency?
A: An iodine deficiency means your body can’t make enough of them, leading to hypothyroidism.
Q:2 What causes iodine deficiency?
A: Since our bodies do not produce iodine, so it must come from our diet. Iodine deficiency is rare in the United States, partly due to the widespread use of iodized salt. Natural sources of iodine include food from the sea and from areas where the soil is rich in iodine.
Q: 3 What are the best sources of iodine?
A: Seaweed, Kombu kelp, Wakame, Nori, Cod, Dairy, Yogurt, Cheese, Iodised salt, Shrimp, Tuna, Eggs, Prunes, and Lima beans are the best food sources for iodine.