Thyroid hormone is the first hormone to have evolved in multicellular organisms when they left the
iodine-rich atmosphere of the sea. Iodine was so essential. The thyroid evolved to make sure it was
always available to cells. The thyroid hormone controls all endocrine organs. The thyroid hormone
is the first hormone to develop in the fetus. First, the thyroid develops, then the central nervous
system develops, with the tissues from the neural tube making the thyroid and then the brain.
Iodine is essential for this. It is crucial not only to grow our brain but control development and
tissue growth. There are thyroid hormone receptors in all cell membranes, all mitochondria, and all
cell nuclei. The thyroid makes 80% t4, 16% t3, and 4% T2 and T1. In addition, 1% of the thyroid
makes 90% of the body’s calcitonin, important for regulating bone formation and vitamin D
activation in the kidneys. That T4 has to be converted into T3, T2, and T1 to be active. Thyroid
hormone, specifically T3, the active thyroid hormone, sparks the release of energy in all cells. All
nutrients, fats, proteins, and carbohydrates can be turned into ATP within each cell, using enzymes
in the mitochondria.
