Iodine is an often forgotten but very important mineral. Recent research suggests that mild iodine deficiency may be a widespread problem in the general population. This may be due to farming areas that may have soil that is low in iodine, iodine deficient diets such as vegan, low iodine food consumption and using sea salt instead of iodised salt.
Iodine is vital for healthy thyroid gland function as it combines with tyrosine (an amino acid) to form the thyroid hormones, thyroxine (T4) and triiodothyronine (T3). These thyroid hormones are essential for the proper functioning of our metabolism as well as bone development and foetal brain development. The recommended dietary intake (RDI) of iodine is 150 µg (micrograms) per day for adult males and females.
The ocean is the largest natural source of iodine in the world as it is found abundantly in all seafood such a fish, oysters and scallops. Other sources of iodine include:
• Nori sheets
• Dulse flakes
• Wakame (type of seaweed)
• Egg yolk
• Iodised salt (normal sea salt does not provide adequate iodine)
• Commercial supermarket breads are fortified with iodine
Dairy products, such as cow’s milk and yoghurt, used to be good sources of iodine, however dairy is no longer a reliable source due to the different sanitation methods of the equipment being used.
Goitrogens are anti-thyroid substances found in some foods that reduce the uptake of iodine by the thyroid gland, therefore causing reduced amounts of thyroid hormones.
Cruciferous vegetables such as cabbage, broccoli, cauliflower, kale, radish, bok choy and brussel sprouts all contain goitrogens. The goitrogen level in these vegetables are significantly lowered when they are cooked and therefore it is important to cook these vegetables before consuming them in order to try reduce anti-thyroid effect.
Due to this minerals important function in our bodies, it is useful to always look out for any signs/symptoms of a potential iodine deficiency, these include:
Hypothyroidism (underactive thyroid gland)
Reproductive issues such as anovulation (absence of menstrual cycle)
Goitre (enlarged thyroid gland)
Balancing the correct amount of iodine in the body can be tricky as too much (toxicity) can also cause damage just as a deficiency can. Here are some signs/symptoms of iodine toxicity to look out for:
• Goitre can also be a sign of an overactive thyroid gland or iodine toxicity, always consult a healthcare professional for medical advice.
• Elevated TSH (thyroid stimulating hormone) levels
• Brassy taste in mouth
• Burning sensation in mouth/throat
It is vital to have optimal levels of iodine during pregnancy as iodine is required for foetal development and a severe deficiency during pregnancy can result in irreversible mental and physical damage to the infant. The RDI increases from 150 micrograms per day to 220 micrograms per day during pregnancy
When considering supplementation with iodine, always consult with a healthcare professional and investigate whether or not you are deficient. Taking an iodine supplement without professional recommendation can be dangerous.