The ratio of iodine in thyroxine

The correct answer is 65%.

 Key Points

• Thyroxine, also known as T4, is a hormone produced by the thyroid gland.
• By weight, thyroxine is about 65% iodine.
• The iodine is necessary for the production of T4, and the hormone cannot be made without it.

 Additional Information

• Iodine is a crucial part of not just thyroxine but also triiodothyronine (T3), another hormone produced by the thyroid gland.
• A lack of iodine in the diet can lead to issues with thyroid hormone production and can result in diseases like goiter and hypothyroidism.
• Iodine is often added to table salt (iodized salt) to ensure that people get an adequate amount in their diets.