Background: Before iodized salt was developed, some people experienced a number of developmental difficulties, including problems with thyroid gland function and mental retardation. In the 1920s, we learned that these conditions could usually be treated easily with the addition of iodide anion to the diet. One easy way to increase iodide intake was to add the anion to table salt. This simple step greatly enhanced health and development. Large amounts of iodide ion are also found in seaweed such as kelp (see picture above) and saltwater fish.

Situation: People from two villages ate lots of salt. People from Salt village used regular salt, while people from Sand village people used iodized salt in their diets, after talking to specialists.

Question: Which village had more people experience developmental difficulties?
Answer: Salt

Situation: People from two villages ate lots of salt. People from Salt village used regular salt, while people from Sand village people used iodized salt in their diets, after talking to specialists.

Question: Which village had fewer people experience developmental difficulties?
Answer: Sand

Situation: People from two villages ate lots of salt. People from Salt village used regular salt, while people from Sand village people used iodized salt in their diets, after talking to specialists.

Question: Which village had fewer people experience thyroid gland problems?
Answer: Sand

Situation: People from two villages ate lots of salt. People from Salt village used regular salt, while people from Sand village people used iodized salt in their diets, after talking to specialists.

Question: Which village had more people experience thyroid gland problems?
Answer: Salt

Situation: People from two villages ate lots of salt. People from Salt village used regular salt, while people from Sand village people used iodized salt in their diets, after talking to specialists.

Question: Which village had more people experience mental retardation?
Answer: Salt

Situation: People from two villages ate lots of salt. People from Salt village used regular salt, while people from Sand village people used iodized salt in their diets, after talking to specialists.

Question: Which village had fewer people experience mental retardation?
Answer: Sand

Situation: People from two villages ate lots of salt. People from Salt village used regular salt, while people from Sand village people used iodized salt in their diets, after talking to specialists.

Question: Which village had fewer people with enhanced health?
Answer: Salt

Situation: People from two villages ate lots of salt. People from Salt village used regular salt, while people from Sand village people used iodized salt in their diets, after talking to specialists.

Question: Which village had more people with enhanced health?
Answer: Sand

Situation: People from two villages ate lots of salt. People from Salt village used regular salt, while people from Sand village people used iodized salt in their diets, after talking to specialists.

Question: Which village had more people with enhanced development?
Answer: Sand

Situation: People from two villages ate lots of salt. People from Salt village used regular salt, while people from Sand village people used iodized salt in their diets, after talking to specialists.

Question: Which village had fewer people with enhanced development?
Answer: Salt