Iodine has been described as one of the most misunderstood and feared of all the elements necessary for human health. My interest in iodine began when I discovered that I was low in it. After a few months of taking an iodine supplement, a large wart on my hand dropped off and all the little warts on my knee disappeared. The wart on my hand had been resistant to all sorts of other treatments and had been growing at a steady rate. As warts are a virus, I was reluctant to have it burned off as it wouldn’t stop more warts growing. After using iodine, the warts never returned, and this was well over five years ago.
Iodine certainly is misunderstood. Perhaps the biggest area of uncertainty is around the RDI.
The current accepted recommended daily intake (RDI) for iodine in New Zealand is 150 micrograms (0.15mg). The average daily intake of iodine for a typical Japanese seaside villager has been estimated at 12mg (80 times more than our RDI). More recent research showed that the intake of an average Japanese citizen may be around 3mg – still 20 times New Zealand’s RDI). Known issues of iodine deficiency, such as breast cysts, breast cancer and prostate cancer, are much lower in Japanese people compared with people in countries like New Zealand where iodine intake is very low.
Like all minerals in human biology, the critical factor is balance. Obviously, having too much iodine is also a problem and it can be toxic. Typically, the first sign of having too much iodine may be skin lesions, a brassy taste in the mouth, a runny nose and development of a goiter. To absorb iodine, there needs to be trace minerals available. The most critical being selenium (another mineral that New Zealand soils are very low in), about 150 mcg of this are needed daily.
When it comes to supplementation everyone is different. Iodine supplementation must be done carefully if there has been any previous thyroid disease or issues. The thyroid is a small butterfly-shaped endocrine gland at the base of your neck (just below your Adam’s apple). The job of the thyroid is to regulate the body’s metabolism. The thyroid is mainly made up of iodine so having adequate levels of this mineral is critical.
Iodine is an anti-bacterial, anti-parasitic, anti-cancer and anti-viral and so, like zinc, is critical for your immune system. There are also strong links to cyst formation and breast tumours with iodine deficiency as well as mental retardation, ADHD and multiple sclerosis.
While our soils are iodine deficient our seafood is not. Seaweed (such as kelp) is the highest source of iodine in New Zealand and is a very good way to supplement. While there is plenty of controversy around what the RDI of iodine should be, we can agree that adding kelp daily and seafood to our diets is safe and beneficial.