Nutrient 5/27

Iodine

What does it do?

Iodine is an essential constituent of your thyroid hormones, which help regulate metabolism (the rate at which your body uses energy). Iodine is a key player in many biochemical reactions that affect heart rate, respiratory rate and a wide variety of other physiological activities.

What are the best food sources?

The iodine content in foods varies widely due to soil content, irrigation and fertilizer. It is usually low in areas that are eroded or are distant from oceans, the source of most of the world’s iodine. Seafood and seaweed are rich natural sources. Processed foods may contain higher levels due to the addition of iodized salt or other additives containing iodine (e.g., calcium iodate). However, salt is not required to be iodized. One-fourth of a teaspoon of iodized table salt contains about 100 micrograms of iodine.

What happens if you don’t get enough?

Due to the widespread use of iodized salt, deficiency is rare in the United States. However, iodine deficiency affects millions of people worldwide and is identified as the most common cause of preventable brain damage in the world. Major international efforts are currently under way to reverse and prevent this problem. Iodine deficiency disease (IDD) results in a range of symptoms from mild to severe including goiter (an enlarged thyroid gland and usually the earliest sign), mental retardation, hypothyroidism (too little thyroid hormone), and varying degrees of growth and development abnormalities.

What happens if you get too much?

salt (नून) 

Individuals can tolerate a wide range of iodine intakes because the thyroid gland regulates the body’s level of this mineral. Acute intakes—those ingested over a short time period—can cause burning of the mouth, throat and stomach; fever; gastrointestinal illness, such as nausea, vomiting and diarrhea; a weak pulse; and coma. In iodine-sufficient populations, chronic intakes at levels above the tolerable upper intake level (UL) have the following adverse effects: goiter (an enlarged thyroid gland), hypothyroidism (too little thyroid hormone), hyperthyroidism (too much thyroid hormone) and thyroiditis (inflammation of the thyroid gland).

How much do you need?

The following table lists the recommended intake for healthy people based on current scientific information.

Life Stage Group	Age Range	Recommended Dietary Allowance/Adequate Intake	Tolerable Upper Intake Level (UL)
Children	1-3 yr.	90 micrograms/day	200 micrograms/day
Children	4-8 yr.	90 micrograms/day	300 micrograms/day
Males	9-13 yr.	120 micrograms/day	600 micrograms/day
Males	14-18 yr.	150 micrograms/day	900 micrograms/day
Males	19-30 yr.	150 micrograms/day	1100 micrograms/day
Males	31-50 yr.	150 micrograms/day	1100 micrograms/day
Males	51-70 yr.	150 micrograms/day	1100 micrograms/day
Males	> 70 yr.	150 micrograms/day	1100 micrograms/day
Females	9-13 yr.	120 micrograms/day	600 micrograms/day
Females	14-18 yr.	150 micrograms/day	900 micrograms/day
Females	19-30 yr.	150 micrograms/day	1100 micrograms/day
Females	31-50 yr.	150 micrograms/day	1100 micrograms/day
Females	51-70 yr.	150 micrograms/day	1100 micrograms/day
Females	> 70 yr.	150 micrograms/day	1100 micrograms/day
Pregnancy	< 18 yr.	220 micrograms/day	900 micrograms/day
Pregnancy	19-30 yr.	220 micrograms/day	1100 micrograms/day
Pregnancy	31-50 yr.	220 micrograms/day	1100 micrograms/day
Lactation	< 18 yr.	290 micrograms/day	900 micrograms/day
Lactation	19-30	290 micrograms/day	1100 micrograms/day
Lactation	31-50 yr.	290 micrograms/day	1100 micrograms/day