Here's someone else's list of what it takes to make thyroxine:
http://naturalthyroidchoices.com/ThyroidNutrients.html
Thyroid Nutrients
I am asked on a regular basis. What should I take? These are some of the nutrients I have taken or continue to take on my journey. It is best to have your levels checked by a health care practitioner in order to get the best possible combination of nutrients for your condition.
Vitamin A- Individuals with low thyroid function (hypothyroidism) have a reduced ability to convert beta-carotene into vitamin A.
Recommended amount: 25,000 IU
Vitamin B2 (Riboflavin)- Riboflavin is needed for the production of corticosteroids, erythropoesis gluconeogenesis, and thyroid enzyme regulation. Assists with ATP production increasing energy along with organification of Iodine.
Recommended amount: 100 mgs 2x / day
Vitamin B3 (Inositol Hexanicotinate)- is needed to increase ATP functionality to help with energy and organification of iodine.
Recommended amount: 500 mgs 2x / day
Vitamin C- Assists in the healthy function of the NIS (sodium iodine symporters) which allows the cells to pull iodine into them.
Recommended amount: 2,000 - 5,000 mgs
Iodine- Critical building block. Iodine is organified to thyroglobulin to create thyroid hormones (T4 - 4 iodine molecules & T3 - 3 Iodine molecules).
Recommended amount: 6 - 50 mgs
L-Tyrosine - This is an amino acid that is used by the thyroid gland. It works with iodine to activate T3 and T4. L-tyrosine attaches itself to iodine atoms to form the active thyroid hormone. Supplementation with L-tyrosine can assist in better sleep and lowered stress. It also aids in the function of the adrenal and pituitary glands.
Recommended amount: 500 mgs
Magnesium- Assists in the regulation of thyroid function. Is a good regulator of muscle relaxation. Activates enzymes in the body.
Recommended amount: 400-500 mgs - Note: A new form of transdermal Magnesium is now available called Ancient Minerals. It can be applied to the skin thus avoiding bowel intolerance and gut absorption issues. Magnesium Oil can be purchased
HERE
Selenium- Assists in the production two enzymes: glutathione peroxidase (reacts with H2O2to reduce H to H2O) and iodothyroinine deiodinase (controls the removal of an iodine molecule to convert from T4 to T3, T3 to T2 and T2 to T1).
Recommended amount: 200 - 400 mcg
Zinc- Assists in the conversion of T4 thyroid hormone to the more active T3 form of thyroid hormone. A simple test with liquid zinc can be done to test for deficiency. If you can taste the zinc then you are not deficient. If you taste nothing then you need to supplement.
Recommended amount: 50 mgs (should be combined with 2 mgs
Copper as they are antagonists and zinc will lower copper levels)
For high RT3 issues (reverse T3) this combo works to bring the T3:RT3 ratio back in line.
Selenium, Zinc, Vit B6 and B12, Iron, Vit D and Iodine: they are all required by the 5-deiodinase enzyme responsible for proper T3 production.
** These recommendations are only general guidelines of nutrients. You should try to find a qualified healthcare practitioner who can custom design a protcol that fits your specific needs.
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So this person lists some extra stuff. You can also check the content of Thyrocsin at iherb, which is meant to be all the raw nutrients needed to produce thyroxine (however the doseage may be insufficient in zinc or tyrosine, and if you have auto immune you should consider taking he max dose of selenium (400mcg).