Iodine is an essential part of growth and development. When iodine levels are low, we may heal slower because our cells our unable to grow properly. Our nails may be weak and slow to grow, our hair may grow more slowly or be lackluster, and our skin may be dull and thin. Conversely, when too much iodine is consumed, hair may go through the growth cycle so fast that it falls out quicker, leading to thin hair. Skin may grow so fast that it thickens and may start to itch. Thus, balance is very important when it comes to this trace mineral. Incorporating the proper amounts of iodine-rich foods into your diet can very clearly affect the way you feel and function.
Iodine deficiency is most often seen in areas that are not near the sea, where access to iodine-rich seafood and sea vegetables is unavailable. Symptoms of iodine deficiency include cold hands and feet, muscle cramps, tendency to gain weight, constipation, poor memory, depression, headaches, swelling, muscle pain and weakness, dry skin, and brittle nails. Low iodine levels can also contribute to infertility and difficulties conceiving, as it is need for healthy reproduction in both men and women [I].
Iodine and Brain Development
Being that iodine is important for growth and development, it is imperative for children. Iodine controls the brain’s development and is vital for intelligence and basic skills such as speech, hearing, and movement. It also plays a critical role in the proper development of the brain, spinal cord, and skeleton during fetal growth [II].
Brain function may very likely be affected in adults with severe iodine deficiencies. For instance, inability to concentrate and “brain fog” can be symptoms of iodine deficiency. Iodine isn’t just needed for brain development, it’s needed for brain function in general.
Iodine, Thyroid, and Energy Production
Iodine is needed for the healthy functioning of almost every cell in the body, but most importantly, it is needed to make thyroid hormones T3 (triiodothyronine) and T4 (thyroxine). These hormones regulate metabolism and energy, thus affecting how we feel and function. They can only be made if we have sufficient levels of fats, proteins and iodine.
Everything we do requires energy. Thyroid hormones tell your body how much energy to make to meet the demands of whatever activity you are doing. If you consume too much iodine, your body will make more of these hormones, resulting in lots of energy, sometimes so much energy that you may experience shaking and a rapid heartbeat in order to release it. If you don’t consume enough iodine, your body decreases its production of thyroid hormones, resulting in not enough energy, and you may experience fatigue, sluggishness, and general apathy.
The highs and lows of energy also relate to body temperature. When you exercise, your body makes lots of energy and you feel hot. When you spend too much time in front of the TV, you feel cold. Likewise, when iodine levels are high, your cells make more energy and body temperature rises, whereas when iodine levels are low, your body temperature decreases. This is why low thyroid hormone levels are associated with cold hands and feet.
Iodine and Weight
Let's connect the dots. If your body is low in iodine and therefore produces energy at a slower rate, what else we be functioning at a slower rate? Your metabolism. Low iodine levels means that your body will be less efficient when it comes to burning calories, making you more prone to weight gain. This is why sometimes a person can eat like a bird and exercise to exhaustion and still not lose weight! If your body has sufficient iodine, your cells make and burn energy more efficiently, making you less prone to weight gain (unless excessive calories are consumed).
Iodine for Protection Against Radiation
Iodine is absorbed via the small intestine and, once in the blood, it is rapidly taken up by the thyroid gland, ovaries, and other tissues for cellular health and hormone production. When an individual is up to par on iodine, the body will not uptake more. Therefore, deficiency of this trace mineral can be dangerous in areas subject to contamination from nuclear disasters (such as Japan during the Fukushima nuclear disaster in March of 2011). This is because the thyroid and other tissues will uptake the radioactive mineral from iodine-rich sources like seaweed, which is very prevalent in the diet of the Japanese culture. This type of iodine contamination and consumption can eventually lead to multiple disorders [III].
Radioactive iodine appears to accumulate in the thyroid, breasts, ovaries, and uterus, making it especially dangerous for women. This is one mineral I recommend getting in sufficient amounts as a preventative measure against breast cancer, thyroid cancer, and ovarian cancer, among others. If you think that iodine may be a concern for you, find a practitioner who is familiar with iodine testing.
Recommended Daily Allowance (RDA)
Men and Women — 150 micrograms (mcg)/day
Pregnant women — 220 mcg/day
Breastfeeding woman — 290 mcg/day
Upper Level Dosage (UL) — 1,100 mcg/day
Iodine Supplementation vs. Food Sources
Large amounts of supplemental iodine may do more harm than good so you need to consult with a healthcare provider if you feel that you may be largely deficient. However, iodine toxicity is rare in the diets of those who obtain their iodine from food sources. For that reason, I recommend getting your iodine from food, not supplements.
It is easy to obtain your daily iodine requirements from food, even if you do not like seafood and would never think of eating a seaweed salad (although they are delicious!). You can get dried kelp granules in shaker jars that you can sprinkle into soups, stews, over salads, eggs, and whatever dish you are cooking—you won’t even taste it! One-quarter teaspoon of dried kelp provides a whopping 2260% of your daily requirements. Himalayan sea salt is also an easy way to add iodine-rich flavor and nutrition to any dish.
If you know that you are very iodine deficient, be weary not to consume large amounts of foods that contain goitrogens such as cabbage, broccoli, cauliflower, brussels sprouts or other cruciferous vegetables. These compounds can inhibit iodine uptake by the thyroid gland. Soybeans and cassava (yucca) also contain goitrogens.
Animal sources: fish, mollusks, shrimp, and tuna
Plant sources: Sea vegetables (such as kelp and dulse), cranberries, navy beans, potatoes (with the peel)
These Wild-Rice Stuffed Sweet Potatoes with Cranberries and Pepitas are a wonderful iodine-rich side dish option! Sprinkle on a little Himalayan sea salt before serving and you've got yourself one metabolism-boosting, energy-evoking, hormone healthy meal!
[I] "Herbs and Supplements: Iodine". U.S. National Library of Medicine, 2015. Web. May. 2016. <https://www.nlm.nih.gov/medlineplus/druginfo/natural/35.html>.
[II] Kapil, Umesh. "Health Consequences of Iodine Deficiency". Sultan Qaboos Univ Med J. 2007 Dec; 7(3): 267–272. Web. May. 2016. <http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3074887/>.
[III] Minoru, Irie. "Radioactive Iodine and the Effect of Consuming Seaweed". The Foundation for Growth Science, 2012. Web. May. 2016. <http://www.childresearch.net/projects/earthquake/2012_01.html>.