What is iodine?
Iodine is a type of atom. (1)
Iodine is a type of halogen. (1) 
Iodine is a type of mineral. (3)

What contains iodine?
table salt may have add iodine
1/4 teaspoon of iodized table salt contains 71 mcg (2,3)
dairy (3)
seaweed – kombu kelp, wakame, nori (3)
certain fish, beans, and fruit (3)
soil (3)
3 oz of cod contains 63 to 99 mcg (3)
fish low in fat have the highest iodine amounts (3)
1 cup of cow’s milk contains 88 to 168 mcg (3)
yogurt (3)
cheese (3)
1 cup of cottage cheese contains 65 mcg (3)
1 oz of cheddar cheese contains 12 mcg (3)
3 oz of shrimp contains mcg (3)
3 oz of tuna contains 17 mcg (3)

Iodine and Humans
Iodine is an essential mineral for humans. (3)
The thyroid gland traps iodine and transforms it into thyroid hormones. (2)
If a person has too much or too little iodine in the body, it can affect the level of thyroid hormones the thyroid gland produces and releases. (2)

What is the RDI for Iodine for humans?
The RDI of iodine is 150 mcg per day for most adults. (3)

Too little IodineNormal Range for IodineToo much Iodine
goiter (3)
hypothyroidism (3)

1. https://en.wikipedia.org/wiki/Iodine
2. https://my.clevelandclinic.org/health/body/23188-thyroid
3. https://www.healthline.com/nutrition/iodine-rich-foods