I recall the sting of iodine tincture on my grazed knees when I was a little girl. It was a very common antiseptic. My mother called it ioeidēs, a Greek word meaning violet. Though it never coloured violet on my knees. I later discovered it was named after the colour of elemental iodine vapour. This was my first encounter with this essential trace element for life. It wasn’t until I started consulting as a Naturopath that I realized how essential it was. Iodine deficiency is one of the most common deficiencies I see in my clinic next to Zinc, Vitamin D and Iron.
Iodine is a constituent of the thyroid hormones, thyroxine (T4) and triiodothyronine (T3). The thyroid gland actively absorbs iodide from the blood to make and release these hormones into the blood, actions that are regulated by a second hormone called TSH or thyroid stimulating hormone, which is secreted by the pituitary. Iodine is concentrated in thyroid tissue and hormones, but 70% of the body’s iodine is distributed in other tissues, including mammary glands, eyes, gastric mucosa, arterial walls, the cervix, and salivary glands.
What is the role of thyroid hormones?
They regulate basal metabolic rate, which is the amount of energy expended at rest. Specifically regulating protein, fat, and carbohydrate metabolism, affecting how human cells use energetic compounds, help regulate long bone growth and are essential for proper development and differentiation of all cells of the human body. They also stimulate vitamin metabolism and regulate heat in the body.
Iodine deficiency also gives rise to hypothyroidism, symptoms of which are extreme fatigue, mental slowing, depression, weight gain, and low basal body temperatures.
Other diseases caused by an iodine deficiency
When a persons diet is low in iodine, the pituitary keeps sending chemical messages to the thyroid, but in vain. The thyroid gland enlarges as it attempts to comply with the pituitary’s demands causing a goiter. It presents as an enlargement of the throat, ranging from a small lump to a huge mass, swallowing problems and breathing problems.
Fibrocystic breast disease
The breast strongly and actively concentrates iodine into breast-milk for the benefit of the developing infant, and may develop a goiter-like hyperplasia, sometimes manifesting as fibrocystic breast disease or lumpy (usually benign) and tender breasts.
Some researchers have found an epidemiologic correlation between iodine deficiency, iodine-deficient goitre and gastric cancer.
Although there isn’t a definitive answer for the cause of autism in children, research has shown that mothers with low levels of iodine are more likely to have an autistic child.
What can contribute to iodine deficiency?
1. Low dietary iodine intake of seafood and seaweed (see next weeks article for a detailed guide of iodine sources)
2. Selenium deficiency. A family of selenium-dependent enzymes called deiodinases converts T4 to T3
6. Oral contraceptive pill
7. Intake of goitrogens, which are substances, that suppress the function of the thyroid gland by interfering with iodine uptake. An example of where goitrogens are found are in the Brassica Family of vegetables. These include broccoli, kale, cauliflower, Brussel sprouts and cabbage. Cooking partially inactivates them. (See next weeks article for a detailed guide of goitrogenic substances)
Next week, in part 2, I outline the richest food sources of iodine, iodine rich recipes and testing for iodine. I also review iodine supplements, which are the best and how much to take.
Image Credit: earthsciencescanada.com