One of the essential ingredients needed by the thyroid to produce T4 is iodine. And not just any iodine. The iodine in the American diet is mainly Sodium Iodide. It’s the wrong kind. What the thyroid needs is Potassium Iodide, the kind found in kelp and seaweed, and high quality supplements.

There are lots of things that can poison the thyroid, like mercury, chlorine, and fluoride. The estrogens in some birth control pills disrupt the conversion of T4 to the much needed inside-the-cell T3, as do the estrogen-mimicking chemicals so prevalent in our foods and environment.

Modern-day life has stacked the deck against a well-functioning thyroid. Many of us have:

Fatigue
Sluggishness
Lacking Ambition
Poor Motivation
Low Energy
Overweight
Cold Extremities
Cracking Skin
No half moons on nails
Hair Loss
Constipation
Low Progesterone
Poor Memory
Poor Concentration
Crying
Personality Changes
Depression
It’s Worse in the Morning

To see the complete picture, let’s follow the thyroid trail from its beginning in the hypothalamus.

The hypothalamus is like the Central Processing (CPU) of the brain in that it regulates energy levels, body temperature, sleep/wake cycle, appetite, fluid intake, blood pressure, heart rate, sexual arousal, and a range of other activities including the thyroid. The hypothalamus senses when your body calls for thyroid activity and releases a substance called Thyroid Release Hormone (TRH) into the pituitary gland in the brain. The pituitary gland then releases a substance called Thyroid Stimulating Hormone (TSH) that travels to the pituitary and tells it to make more T4.

The process begins in the hypothalamus with TRH, travels to the pituitary for TSH, down to the pituitary for T4, and then finally into every cell where the T4 is converted into T3.

Let me repeat that: it all begins in the brain. If the hypothalamus has a low-grade bacterial of fungal infection, little or no TRH will be produced to start the cascade. If the pituitary has a low-grade bacterial or fungal infection there will be little or no TRH released, and that will stop the cascade.

Let’s say all that’s fine and the thyroid is producing normal levels of T4. Since most of the T4 to T3 conversion occurs inside the cell where it is used, you may have a normal T4 circulating in your blood, but a low T3 inside your cell. There is no blood test that can see inside your cells and measure their T3. It’s not what’s floating around in your blood, but what’s happening inside your cell that counts.

Let’s take a look at what happens inside your cells. If your Membrane Potential is at or near the normal 70mv, T4 is drawn into your cells where it meets up with the Deiodinase Enzyme. If meets with a Type 1 or a Type 2 Deiodinase Enzyme, and if your cells have the necessary selenium cysteine, manganese, zinc and copper co-enzymes, the T4 will be converted to T3 and your cells become fully energized. If the T4 meets with a Type 3 Deiodinase Enzyme, then the T4 is converted to Reverse T3 and you suddenly have some of the classic symptoms of Hypothyroidism.

There isn’t much difference in the molecular structure between T4, T3, and Reverse T3. The difference is just one Iodine atom and that atom’s location. T4 has 4 Iodine:

Remove just one Iodine from the correct location and you have good T3:

Most common causes of thyroid malfunction are:

• Mercury
• Chlorine and fluoride halogens replacing iodine
• Hypothalamus dysfunction
• Pituitary dysfunction
• Strong emotional states
• Nerve pressure from whiplash
• Prolonged intake of sugar
• Overeating
• Birth control pills, amphetamines, cortisone
• Taking synthetic thyroid hormones
• X-rays striking the thyroid
• Lack of iodine in the diet
• An imbalance in estrogen

If you are on thyroid hormone replacement therapy, the following chart will give you an indication of what to expect. The higher the T3, the better you are. And conversely, the higher the Reverse T3, the lower your level of health.

In-the-Cell T4 to T3 Conversion ratio:
　　　　　     T3 　　 　Reverse T3　
Armour　 　   89%　 　　 11%
Naturethroid　 82%　  　    18%
Synthroid　　  51%　　 　 49%
Westhroid        28%　　　   62%
Levothyroxine   12%　　   　88% 
Levoxyl　　　  11%　　　　89%    
Eltroxin　　　　8%　　  　92%