How much iodine do you need in your diet and what is the best dosage to take of this dietary supplement?
The daily requirement for iodine established by the US Food and Drug Administration is 150 micrograms (mcg) per day for adult men and women.
There are some instances in which the RDA (Recommended Daily Allowance) for this mineral is higher or lower, such as in pregnant or nursing women or in young children.
According to University Health News, iodine is a mineral that is essential for health on several different levels. It is important to ensure adequate dietary intake of this mineral to prevent symptoms of deficiency and to support optimal health and well-being.
Many people around the world are at risk of an iodine deficiency. If you do not meet your daily requirement through food, oral supplement dosages can be used. However, taking too much iodine per day can also cause adverse effects.



- Important for thyroid hormones & metabolism
- Supports mental function & immunity
- Essential nutrient with multiple roles in the body
Why Do You Need Iodine?
Iodine is a trace chemical element; denoted “I” and with atomic number 53. It exists in the soil and gets taken up by plants as they grow.
The body only needs a small amount of this trace mineral to ensure proper functioning. However, in areas of the world with low-iodine content soil, getting enough to meet bodily needs can be difficult.
Iodine plays a key role in several different bodily processes. It is stored in and used largely by the thyroid gland. Without adequate iodine, the thyroid gland cannot efficiently perform its duties, which can impair general health.
Iodine is attached to the amino acid tyrosine to produce T3 (triiodothyronine) and T4 (thyroxine) thyroid hormones.
According to WebMD, every cell in the body is affected by thyroid hormones. Some of the functions they affect include:
- Regulating caloric metabolism, modulating weight loss and weight gain;
- Facilitating efficient food movement through the digestive system;
- Keeping body temperature stable (thermoregulation);
- Controlling the speed and rhythms of heartbeat;
- Modulating cell death (apoptosis);
- Regulating muscular contraction;
Thyroid hormones also affect other functions including respiration, menstruation, lipid metabolism and functioning of peripheral and central nervous systems.
Getting the proper daily iodine dosage is important for more than thyroid health. According to Dr. Joseph Mercola, chronic deficiency can result in:
- Enlarged thyroid (goiter);
- Certain forms of cancer;
- Mental retardation;
- Hypothyroidism;
Dr. Mercola also asserts that a lack of iodine can cause severely stunted mental and physical development in a condition called cretinism.
The World Health Organization (WHO) states that roughly 40% of the world’s population is at risk for iodine deficiency. The WHO also states that iodine deficiency is the leading worldwide cause of mental retardation in fetuses and newborn babies.
Ensuring adequate maternal iodine intake in the diet during and for up to one year after pregnancy is critical for developmental health in developing babies and breastfeeding infants.
Dietary Requirements
The US RDA (recommended daily allowance) for iodine is 150 micrograms (mcg) each day in healthy adults.
According to the National Institutes of Health (NIH) Fact Sheet on Iodine, 150 mcg/day is recommended for all healthy people at least 14 years of age.
Children between 9 and 13 years of age should get 120 mcg/day and those between 1 and 8 years should get 90 mcg/day.
Because of the importance of iodine in developing and newborn babies, it is recommended that pregnant women get at least 220 mcg/day of iodine. When nursing, NIH states that mothers should get at least 290 mcg/day.
Is the US RDA High Enough?
Many health professionals believe that iodine deficiency is even more prevalent than is commonly believed.
The RDA is based on the minimum amount of this mineral required in the diet to prevent thyroid enlargement (goiter development). It does not address optimal levels of this mineral for whole-body health.
Some doctors, such as Dr. David Brownstein argue that because the RDA was set with the sole intention of preventing goiter, that it does not promote “total body iodine sufficiency”.
Dr. Jorge Flechas claims that the absence of iodine in cells in the chief cause of cancer. He says that this compound induces apoptosis in cancer cells, causing their self destruction.
Various toxins compete with iodine for uptake into the cells, especially in the thyroid gland. Some of the most common of these are fluoride, chlorine and bromine.
Because of the prevalence of food-based, environmental, prescription drug and other toxins, the current RDA for iodine may be insufficient for some. Dr. Brownstein claims that about 95% of more than 6000 patients he has tested over the years have been deficient.
How Much Iodine Do I Need Each Day?
In some countries, average dietary iodine intake is much higher than it is in North America. According to the FDA’s Total Diet Study [1], the average American gets “138 to 353 mcg/day across all age and gender groups.”
However, according to the Natural Medicines Comprehensive Database (NMCD), in Japan, the average diet provides between “5280 mcg to 13,800 mcg without adverse outcomes.” [2]
According to NIH, the Upper Tolerable Level (UL) for iodine is 1100 mcg/day for those over 19 years of age.
If you are trying to determine the best iodine dosage for yourself or someone in your family, it is best to seek medical advice.
Various factors can affect optimal intake including age, health history, diet, geographic location, exercise level, exposure to toxic halogens and prescription drug use.
How to Increase Consumption
Increasing consumption of iodine-rich foods is one of the best ways to get more of this important trace mineral. You can get more from your diet by including the following food types:
- Sea vegetables like kelp, nori, dulse, kombu and arame;
- Wild-caught sea creatures that eat sea vegetables;
- Navy, pinto and kidney and other beans;
- Cranberries and strawberries;
- Yogurt and cheese;
- Potatoes;
Green leafy vegetables, eggs, tuna and organ meats also contain good amounts of iodine. Including more of these foods in your daily meal plans can help to elevate your levels and ensure optimal thyroid and overall health. Make sure to always choose organic options for these and other foods.
You can also consider supplement options including nascent iodine, potassium iodide, sodium iodide, Lugol’s solution, iodine tinctures and radioactive iodine. Ask your doctor which of these might be helpful for meeting your health goals.
Note that overuse of some forms of supplements can increase the risk of adverse effects. It is important that these products are used properly to minimize health risks.
Side Effects
According to the NMCD, Iodine is rated as Likely Safe when taken orally and appropriately in amounts that do not exceed the UL of 1100 mcg/day.
Some users do experience negative effects when increasing their consumption of this mineral. One study showed that a saturated solution of potassium iodide (SSKI) caused abdominal pain and/or nausea in 14% of users.
Some of the other more commonly experienced side effects of iodine supplementation include headache, diarrhea, runny nose, a skin rash and a metallic taste in the mouth. [3]
NMCD states that this supplement can also interact with certain types of drugs including ACE inhibitors, antithyroid medications, lithium and potassium-sparing diuretics. Iodine may also interact with health conditions like autoimmune thyroiditis and dermatitis herpetiformis.
You should discuss the possible benefits, side effects and interactions of iodine with a doctor before beginning to increase consumption or use a supplement.
- Murray CW1, Egan SK, Kim H, Beru N, Bolger PM. US Food and Drug Administration's Total Diet Study: dietary intake of perchlorate and iodine. J Expo Sci Environ Epidemiol. 2008 Nov;18(6):571-80. doi: 10.1038/sj.jes.7500648. Epub 2008 Jan 2.
- Patrick L1. Iodine: deficiency and therapeutic considerations. Altern Med Rev. 2008 Jun;13(2):116-27.
- Cabezas C1, Bustamante B, Holgado W, Begue RE. Treatment of cutaneous sporotrichosis with one daily dose of potassium iodide. Pediatr Infect Dis J. 1996 Apr;15(4):352-4.
Article last updated on: July 9th, 2018 by Nootriment