Danielle: An excellent site for your friend to visit on thyroid information is Dr. Mary Shomon's site at:

http://www.thyroid-info.com/articles.htm

She has written books on the subject and has written articles about what foods really affect the thyroid such as Soy (very bad for thyroid), and no she's not affiliated with the Weston Price Foundation (soy lovers always pooh-pooh the Weston Price Foundation). Coconut oil is very good for the thyroid besides many other things. I use it exclusively for cooking.