Think about your daily iodine intake for a minute. Are you meeting your daily needs? The World Health Organization (WHO) says getting enough of this essential trace element can protect against thyroid diseases such as goitre. The table below shows the recommended daily amounts for adults and children.
You might be surprised to learn the minimum Iodine daily intake the World Health Organization recommends for a healthy body weight. Everyone’s different and your minium Iodine daily intake might be different from mine. Regardless, this article will tell you what you need to know about the importance of Iodine in our diets and food sources.
Iodine Daily Intake
Iodine is a trace element that is naturally present in some foods, is added to some types of salt, and is available as a dietary supplement. Iodine is an essential component of the thyroid hormones thyroxine (T4) and triiodothyronine (T3). Thyroid hormones regulate many important biochemical reactions, including protein synthesis and enzymatic activity, and are critical determinants of metabolic activity [1,2]. They are also required for proper skeletal and central nervous system development in fetuses and infants.
Thyroid function is primarily regulated by thyroid-stimulating hormone (TSH), also known as thyrotropin. It is secreted by the pituitary gland to control thyroid hormone production and secretion, thereby protecting the body from hypothyroidism and hyperthyroidism. TSH secretion increases thyroidal uptake of iodine and stimulates the synthesis and release of T3 and T4. In the absence of sufficient iodine, TSH levels remain elevated, leading to goiter, an enlargement of the thyroid gland that reflects the body’s attempt to trap more iodine from the circulation and produce thyroid hormones. Iodine may have other physiological functions in the body as well. For example, it appears to play a role in immune response and might have a beneficial effect on mammary dysplasia and fibrocystic breast disease.
The earth’s soils contain varying amounts of iodine, which in turn affects the iodine content of crops. In some regions of the world, iodine-deficient soils are common, increasing the risk of iodine deficiency among people who consume foods primarily from those areas. Salt iodization programs, which many countries have implemented, have dramatically reduced the prevalence of iodine deficiency worldwide [2,3].
Iodine in food and iodized salt is present in several chemical forms including sodium and potassium salts, inorganic iodine (I2), iodate, and iodide, the reduced form of iodine . Iodine rarely occurs as the element, but rather as a salt; for this reason, it is referred to as iodide and not iodine. Iodide is quickly and almost completely absorbed in the stomach and duodenum. Iodate is reduced in the gastrointestinal tract and absorbed as iodide [2,5]. When iodide enters the circulation, the thyroid gland concentrates it in appropriate amounts for thyroid hormone synthesis and most of the remaining amount is excreted in the urine . The iodine-replete healthy adult has about 15–20 mg of iodine, 70%–80% of which is contained in the thyroid .
Median urinary iodine concentrations of 100–199 mcg/L in children and adults, 150–249 mcg/L in pregnant women and >100 mcg/L in lactating women indicate iodine intakes are adequate . Values lower than 100 mcg/L in children and non-pregnant adults indicate insufficient iodine intake, although iodine deficiency is not classified as severe until urinary iodine levels are lower than 20 mcg/L.
Intake recommendations for iodine and other nutrients are provided in the Dietary Reference Intakes (DRIs) developed by the Food and Nutrition Board (FNB) at the Institute of Medicine of the National Academies (formerly National Academy of Sciences) . DRI is the general term for a set of reference values used for planning and assessing nutrient intakes of healthy people. These values, which vary by age and gender , include:
- Recommended Dietary Allowance (RDA): Average daily level of intake sufficient to meet the nutrient requirements of nearly all (97%–98%) healthy individuals; often used to plan nutritionally adequate diets for individuals.
- Adequate Intake (AI): Intake at this level is assumed to ensure nutritional adequacy; established when evidence is insufficient to develop an RDA.
- Estimated Average Requirement (EAR): Average daily level of intake estimated to meet the requirements of 50% of healthy individuals; usually used to assess the nutrient intakes of groups of people and to plan nutritionally adequate diets for them; can also be used to assess the nutrient intakes of individuals.
- Tolerable Upper Intake Level (UL): Maximum daily intake unlikely to cause adverse health effects.
Table 1 lists the current RDAs for iodine . For infants from birth to 12 months, the FNB established an AI for iodine that is equivalent to the mean intake of iodine in healthy, breastfed infants in the United States.
|Birth to 6 months||110 mcg*||110 mcg*|
|7–12 months||130 mcg*||130 mcg*|
|1–3 years||90 mcg||90 mcg|
|4–8 years||90 mcg||90 mcg|
|9–13 years||120 mcg||120 mcg|
|14–18 years||150 mcg||150 mcg||220 mcg||290 mcg|
|19+ years||150 mcg||150 mcg||220 mcg||290 mcg|
* Adequate Intake (AI)
The World Health Organization (WHO), United Nations Children’s Fund (UNICEF), and the International Council for the Control of Iodine Deficiency Disorders (ICCIDD) recommend a slightly higher iodine intake for pregnant women of 250 mcg per day [3,7].
Sources of Iodine
Seaweed (such as kelp, nori, kombu, and wakame) is one of the best food sources of iodine . Other good sources include fish and other seafood, as well as eggs (see Table 2). Iodine is also present in human breast milk [2,5] and infant formulas .
Dairy products contain iodine. However, the amount of iodine in dairy products varies by whether the cows received iodine feed supplements and whether iodophor sanitizing agents were used to clean the cows and milk-processing equipment . For example, an analysis of 44 samples of nonfat milk found a range of 38 to 159 mcg per cup (with an average of 85 mcg/cup used for Table 2) . Plant-based beverages used as milk substitutes, such as soy and almond beverages, contain relatively small amounts of iodine.
Most commercially prepared bread contains very little iodine unless the manufacturer has used potassium iodate or calcium iodate as a dough conditioner [10,11]. Manufacturers list dough conditioners as an ingredient on product labels but are not required to include iodine on the Nutrition Facts label , even though these conditioners provide a substantial amount of iodine. According to 2019 data from the USDA Branded Food Products Database, approximately 20% of ingredient labels for white bread, whole-wheat bread, hamburger buns, and hot dog buns listed iodate . Pasta is not a source of iodine unless it is prepared in water containing iodized salt because it absorbs some of the iodine .
Most fruits and vegetables are poor sources of iodine, and the amounts they contain are affected by the iodine content of the soil, fertilizer use, and irrigation practices [2,10]. This variability affects the iodine content of meat and animal products because of its impact on the iodine content of foods that the animals consume . The iodine amounts in different seaweed species also vary greatly. For example, commercially available seaweeds in whole or sheet form have iodine concentrations ranging from 16 mcg/g to 2,984 mcg/g . For these reasons, the values for the foods listed in Table 2 are approximate but can be used as a guide for estimating iodine intakes.
How much iodine should you take in a day?
The US recommended daily intake for iodine is 150 mcg/day for adults, and the FDA’s limit is set at 1 mg/day. Among functional medicine practitioners, there is no consensus on the actual human requirement for daily iodine.
How much iodine is in iodine plus 2?
Iodine Plus2– It contains 12.5 mgs of Iodine / Iodide along with 15 mcg of Selenium as well as 15 mgs B2 (Riboflavin). The iodine protocol includes 200 – 400 mcg of Selenium and in some cases requires ATP CoFactors which are a combination of 100 mgs of B2 (Riboflavinu) and 500 mgs B3 (Niacin). One bottle contains 60 tablets and is $25.
Which is the best iodine supplement for You?
Lugol’s liquid– Iodine / Potassium Iodide – 2% and 5% solutions. 2% solution is 2.5 mgs / drop. 5% solution is 6.25 mgs / drop. ii. Iodoral– Lugol’s formula in pill form – Iodine / Potassium Iodide – 12.5 mgs & 50 mgs iii. Biotics Research Iodizyme– 12.5 mgs per tablet of Iodine / Iodide iv.
How much iodine do Japanese women need a day?
To put these doses in perspective the average Japanese adult consumes 5,280 to 13,800mcg of iodine a day with no negative effects and a plethora of benefits. ( 2) Japanese women who consume a traditional high-seaweed diet also have a low incidence of benign and malignant breast disease.
Can you take too much iodine supplement?
You’re probably more likely to consume too much iodine, so never take an iodine supplement without speaking to your doctor first. Too much iodine can interfere with your thyroid and leave you with a host of unwanted symptoms.
What is the best iodine to take?
Among the liquid-based iodine solution, J. Crow’s is the best. It has a high concentration of iodine, and is used by many people with thyroid issues to address iodine deficiencies rapidly and effectively.
What are the benefits of taking iodine daily?
The health benefits of iodine include the formation of healthy and shiny skin, teeth, and hair. It is an important element for hair care, as lack of this mineral can result in hair loss. Moreover, it also speeds up hair growth and increases follicle strength.
How much iodine is too much?
The recommended daily limit for iodine intake is 150 micrograms for men and non-pregnant women. The recommended daily intake is 220 to 250 micrograms for pregnant women and 250 to 290 micrograms for women who are breast-feeding.
Have you heard the word ”iodine” before?
Iodine is a mineral that is necessary for children to develop their bones and their brains.
It also becomes the material of thyroid hormones that is essential to metabolize healthily and maintain a healthy weight.
Lack of iodine causes iodine deficiency which is the factor of brain disorder.
Other than that, your neck gets swollen (goiter), you may gain weight, and decreases your energy and causes pathergasia.
Hypothyreosis, low blood pressure, and feeling of fatigue are also some symptoms.
Especially pregnant women need to be careful of being lacking of iodine.
When you are pregnant, you need 50% more iodine for your baby.
Also, after childbirth, you feed breast milk to your baby. If you are a lack of iodine, your baby will be lack of iodine as well.
Furthermore, if you are a lack of iodine while you are pregnant, the risk of still-birth will be high.
According to the research, there are actually 35,000,000 people who are lack of iodine in this world because they rarely get to eat food that contains enough iodine in their countries.
So, you need to eat food that contains enough iodine for your body.
Then, what should you eat to take enough iodine?
Let’s check out the list below.
|dried seaweed (nori)||2,100|
As you can see from the table, seaweed contains a lot of iodine.Well, did you know that seaweed such as kelp and mozuku are good for your health and your body? the effects of seaweeds
Especially Fucoidan contained in seaweed is currently a topic of conversation in health businesses.
You will be surprised that Fucoidan has many great benefits for our body and health.
Please check Fucoidan’s amazing health benefits! →
However, even if it is good for your health, eating too much seaweed is not good because it causes harm to the body.
Eating too much seaweeds causes hypothyroidism and thyroid cancer.
Especially those who have abnormal thyroid such as chronic thyroiditis, radioactive iodine treatment, and thyroid got smaller after taking a surgery should be careful when you eat seaweed.
Also, gargling with the popidone iodine every day is not a good idea because mouth wash (popidone iodine) contains a lot of iodine.
You can tell that taking too much iodine is not good as well.
Then, how much is the appropriate daily intake of iodine?
Daily recommended dietary allowance of iodine is 0.13mg and you shouldn’t take more than 3mg a day.
|Iodine Intake standard (㎍/day)|
|1-2 years old||35/250||50/250|
|3-5 years old||45/350||60/350|
|6-7 years old||55/500||75/500|
|8-9 years old||65/500||90/500|
|12-14 years old||100/1200||140/1200|
|15-17 years old||100/2000||140/2000|
|18-29 years old||95/3000||130/3000|
|30-49 years old||95/3000||130/3000|
|50-69 years old||95/3000||130/3000|
|more than 70 years old||95/3000||130/3000|
|Pregnant woman||-||plus 110/2000|
|RDA→recommended dietary allowance|
1.5-2mg of iodine is taken from 5-7g of hijiki seaweed.
The average daily intake of iodine for Japanese people is 1-3mg which means they are taking an excessive amount of iodine every day.
A healthy body can excrete the excess intake, however, in rare cases, it causes supernumerary symptoms because of excess intake of seaweeds and supplements.