VOA健康报道2025--Doctors Concerned about Return of Iodine Deficiency

A century ago, iodine¹ deficiency affected² children across much of the United States. The problem mostly disappeared during the 1900s after iodine was added to common foods. But doctors are now seeing higher iodine deficiency rates. The rises are blamed on dietary changes and new food manufacturing methods.

What is iodine?

Iodine is an element found in seawater and in some soils — mostly in coastal³ areas. A French chemist accidentally discovered the substance in 1811. Iodine's name comes from a Greek word meaning violet-colored.

Iodized salt is displayed for a photograph in Philadelphia on Monday, Jan. 6, 2025. (AP Photo/Jonathan Poet)

Iodized salt is displayed for a photograph in Philadelphia on Monday, Jan. 6, 2025. (AP Photo/Jonathan Poet)

Later in the 1800s, scientists began to understand that people need iodine to control their metabolism⁴ and stay healthy. The element is also important for a child's brain development.

One sign of iodine deficiency is an increase in size, or swelling⁵, of the neck. This growth in the neck is known as a goiter. It can appear when the thyroid gland⁶ grows to make up for too little iodine to produce hormones⁷ that control certain body processes.

In the early 1900s, goiters were commonly seen in children in some parts of the United States. Some of the children showed other symptoms in addition to goiters. These included being smaller or experiencing deafness.

Adding iodine to salt

In the past, public health experts realized they could not solve the iodine deficiency problem by feeding everyone seaweed and seafood⁸. But they learned iodine can be included with table salt.

This form of salt, known as iodized salt, first became available in 1924. By the 1950s, more than 70 percent of U.S. households used iodized table salt. Bread and some other foods also had iodine. As a result, iodine deficiency in the U.S. became rare.

But diets have changed over the years. Processed foods now make up a large part of the American diet. Although these foods contain a lot of salt, it is not iodized. Leading bread makers⁹ also no longer add iodine. And for people who do salt their food, it is popular now to use kosher salt, Himalayan rock salt or other products that do not contain iodine.

“People have forgotten why there's iodine in salt,” said Dr. Elizabeth Pearce of Boston Medical Center. She is a leader in the Iodine Global Network, a nongovernmental agency working to end conditions linked to iodine deficiency. Pearce noted¹⁰ there had been a reported 50 percent drop in U.S. iodine levels studied during the 1970s through the 1990s.

How much iodine is enough?

While most Americans are getting enough iodine through diet, doctors worry this is not the case for women and children – the two groups most likely to be hurt by iodine deficiency.

The American Academy of Pediatrics and other medical groups advise that all pregnant and breastfeeding women get 150 micrograms of iodine each day.

In the last 15 years or so, U.S. researchers have increasingly reported seeing mild iodine deficiency in pregnant women. A Michigan State University study of about 460 pregnant women found about 25 percent of them were not getting enough. That study's lead writer, Jean Kerver, noted that many vitamins for pregnant women do not contain iodine. As a result, doctors suggest that pregnant or breastfeeding women check labels to make sure the vitamins or supplements they take have iodine.

Some studies have linked even mild iodine deficiency to a lower score on an intelligence test known as an intelligence quotient (IQ) test. But experts say there has not yet been enough research to establish exactly how the U.S. population is being affected by iodine deficiency.

Dr. Monica Serrano-Gonzalez of Brown University said she and other doctors had seen five cases of iodine deficiency in children visiting a local health center in Providence¹¹, Rhode Island. “We're concerned this may be increasing, especially in patients with restricted diets.”

Serrano-Gonzalez called for increasing publicity¹² about the problem in order to prevent it from getting worse. She said, “This needs to be on people's radar¹³.”

I'm John Russell.

Mike Stobbe reported on this story for the Associated Press. John Russell adapted it for VOA Learning English.

__________________________________________

Words in This Story

deficiency – n. a shortage of substances that are important or necessary for health

metabolism – n. all the chemical processes in the human body, especially the ones that use food

symptom – n. a physical feeling or problem that shows a person has a particular disease

label – n. written or printed material placed on a product to give more information about its contents

1 iodine   

n.碘，碘酒

参考例句：

• The doctor painted iodine on the cut.医生在伤口上涂点碘酒。
• Iodine tends to localize in the thyroid.碘容易集于甲状腺。

2 affected   

adj.不自然的，假装的

参考例句：

• She showed an affected interest in our subject.她假装对我们的课题感到兴趣。
• His manners are affected.他的态度不自然。

3 coastal   

adj.海岸的，沿海的，沿岸的

参考例句：

• The ocean waves are slowly eating away the coastal rocks.大海的波浪慢慢地侵蚀着岸边的岩石。
• This country will fortify the coastal areas.该国将加强沿海地区的防御。

4 metabolism   

n.新陈代谢

参考例句：

• After years of dieting,Carol's metabolism was completely out of whack.经过数年的节食，卡罗尔的新陈代谢完全紊乱了。
• All living matter undergoes a process of metabolism.生物都有新陈代谢。

5 swelling   

n.肿胀

参考例句：

• Use ice to reduce the swelling. 用冰敷消肿。
• There is a marked swelling of the lymph nodes. 淋巴结处有明显的肿块。

6 gland   

n.腺体，(机)密封压盖，填料盖

参考例句：

• This is a snake's poison gland.这就是蛇的毒腺。
• Her mother has an underactive adrenal gland.她的母亲肾上腺机能不全。

7 hormones   

n. 荷尔蒙，激素 名词hormone的复数形式

参考例句：

• This hormone interacts closely with other hormones in the body. 这种荷尔蒙与体內其他荷尔蒙紧密地相互作用。
• The adrenals produce a large per cent of a man's sex hormones. 肾上腺分泌人体的大部分性激素。

8 seafood   

n.海产食品，海味，海鲜

参考例句：

• There's an excellent seafood restaurant near here.离这儿不远有家非常不错的海鲜馆。
• Shrimps are a popular type of seafood.小虾是比较普遍的一种海味。

9 makers   

n.制造者，制造商（maker的复数形式）

参考例句：

• The makers of the product assured us that there had been no sacrifice of quality. 这一产品的制造商向我们保证说他们没有牺牲质量。
• The makers are about to launch out a new product. 制造商们马上要生产一种新产品。 来自《简明英汉词典》

10 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。

11 providence   

n.深谋远虑，天道，天意；远见；节约；上帝

参考例句：

• It is tempting Providence to go in that old boat.乘那艘旧船前往是冒大险。
• To act as you have done is to fly in the face of Providence.照你的所作所为那样去行事，是违背上帝的意志的。

12 publicity   

n.众所周知，闻名；宣传，广告

参考例句：

• The singer star's marriage got a lot of publicity.这位歌星的婚事引起了公众的关注。
• He dismissed the event as just a publicity gimmick.他不理会这件事，只当它是一种宣传手法。

13 radar   

n.雷达，无线电探测器

参考例句：

• They are following the flight of an aircraft by radar.他们正在用雷达追踪一架飞机的飞行。
• Enemy ships were detected on the radar.敌舰的影像已显现在雷达上。