The amount of iodine found in most natural foods is typically quite small and varies depending on environmental factors such as the soil concentration of iodine and the use of fertilizers. Some of the richest food sources of iodine are often processed foods that contain iodized salt, and breads that contain iodate dough conditioners.
Sea vegetables are an excellent source of iodine. Yogurt, cow’s milk, eggs, and strawberries are very good sources of idone. Good sources include mozzarella cheese.
Fish and shellfish require their own special category when it comes to iodine content, because the amount of iodine they contain is not always easy to predict. For example, the amount of iodine found in fish may not match up very predictably with the amount found in their home waters, or even with their diet. Four ounces of very low iodine fish might only provide about 70 micrograms of iodine, or less than half of the adult RDA. By contrast, four ounces of very high iodine fish might contain as much as 1,000 micrograms of iodine – an amount just below the Tolerable Upper Limit (UL, or safety level) of 1,100 micrograms.
Due to the great variability in fish iodine content, and the relative lack of good information for consumers to base their nutritional decisions in this area, we would not recommend reliance on fish alone to provide all of your dietary iodine needs. However, you can count on getting iodine from most fish, and on any one particular day, we would recommend thinking about a 4-6 ounce fish meal serving as providing at least 50% of your iodine needs. Conversely, if you are trying to greatly restrict your iodine intake, you might want to eat fish on a less frequent basis to lower your risk of iodine intake above the RDA level.
Introduction to Nutrient Rating System Chart
In order to better help you identify foods that feature a high concentration of nutrients for the calories they contain, we created a Food Rating System. This system allows us to highlight the foods that are especially rich in particular nutrients. The following chart shows the World’s Healthiest Foods that are either an excellent, very good, or good source of iodine. Next to each food name, you’ll find the serving size we used to calculate the food’s nutrient composition, the calories contained in the serving, the amount of iodine contained in one serving size of the food, the percent Daily Value (DV%) that this amount represents, the nutrient density that we calculated for this food and nutrient, and the rating we established in our rating system. For most of our nutrient ratings, we adopted the government standards for food labeling that are found in the U.S. Food and Drug Administration’s “Reference Values for Nutrition Labeling.”Read more background information and details of our rating system.
|World’s Healthiest Foods ranked as quality sources of:
|Kelp (sea vegetable)||0.25 cup||8.6||415.00||276.7||579.1||excellent|
|Yogurt, low-fat||1 cup||155.1||87.22||58.1||6.8||very good|
|Cow’s milk, 2%||1 cup||121.2||58.56||39.0||5.8||very good|
|Egg, whole, boiled||1 each||68.2||23.76||15.8||4.2||very good|
|Strawberries||1 cup||43.2||12.96||8.6||3.6||very good|
|Mozzarella cheese, part-skim, shredded||1 oz-wt||72.1||10.09||6.7||1.7||good|
What are current public health recommendations for iodine?
In 2000, the Institute of Medicine at the National Academy of Sciences developed new Dietary Reference Intakes for iodine. Adequate Intakes were established for children up to one year old, and Recommended Dietary Allowances were determined for all people over one year old. These recommendations appear below:
- 0-6 months: 110 mcg
- 7-12 months: 130 mcg
- 1-8 years: 90 mcg
- Boys 9-13 years: 120 mcg
- Girls 9-13 years: 120 mcg
- Boys 14-18 years: 150 mcg
- Girls 14-18 years: 150 mcg
- Men 19 years and older: 150 mcg
- Women 19 years and older: 150 mcg
- Pregnant women 14 years and older: 220 mcg
- Lactating women 14 years and older: 290 mcg
In an attempt to prevent these symptoms of iodine toxicity, the Institute of Medicine established the following Tolerable Upper Intake Levels (UL) for iodine:
- 1-3 years: 900 mcg
- 4-8 years: 300 mcg
- 9-13 years: 600 mcg
- 14-18 years: 900 mcg
- 19 years and older: 1,100 mcg
- Pregnant women 14-18 years: 900 mcg
- Pregnant women 19 years and older: 1,100 mcg
- Lactating women 14-18 years: 900 mcg
- Lactating women 19 years and older: 1,100 mcg
For more details on this, see the Toxicity Symptoms section above.
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