Yes, I realize your question was about replacement hormone therapy. I promise I wasn't digressing or trying to change the subject... These things all go hand in hand since being low in some vitamins/minerals can cause thyroid hormone levels to be on the low side, since they are necessary for proper production or absorption of thyroid hormones.
In addition, deficiency of some vitamins/minerals, such as vitamin D, can cause hypo-like symptoms. It's good that you're taking the vitamin D supplement... vitamin D should be about 60-70; some say 80-100, but vitamin D is toxic if it gets too high...
Have you been offered replacement hormones, by your doctor? As I noted previously, your thyroid hormone levels are well within the ranges, though on the low side. Most doctors won't treat (offer replacement hormones) unless labs are out of range, particularly, TSH and yours would be considered "pristine" by most standards.
A very few doctors will prescribe hormone therapy in the case of a goiter, as the hormones will sometimes help shrink the goiter. If your doctor is willing to prescribe the hormones, I'd probably take them up on it.
I would, however, stop taking iodine. Too much iodine is a cause of hypothyroidism, just as too little can be a cause. Even though your antibody tests don't indicate Hashimoto's, that doesn't mean you don't have it and since you do seem to have a goiter, iodine has been shown to make the autoimmune response worse and is not recommended.
Since you haven't had vitamin B12 tested, I'd ask for that, as soon as possible.
Thank you for the clarification on the T4 and T3... It's good to know that your doctor is, at least, ordering the proper tests (Free T4 and Free T3).
Are you already taking a replacement thyroid hormone medication? If so, which medication and what dosage are you on?
If you aren't already on a replacement medication, unfortunately, it's unlikely a doctor will prescribe replacement hormones for you, because, your results, while, both, slightly on the low side (FT3 is at 49% of range and FT4 is at 40% of range) are within their ranges, with what's considered a "pristine" TSH level.
Your antibody counts are also within normal ranges, indicating that you don't have Hashimoto's - or at least, antibodies haven't ramped up yet. Thyroid nodules are very common and usually are nothing to worry about. Some people have been diagnosed with Hashimoto's based on characteristics of nodules, but there does have to be indication of inflammation and thyroid swelling, along with other indications for this to happen.
What supplements are you taking? Have you been tested for vitamin B-12 and vitamin D deficiency deficiencies? Have you had ferritin tested? If so, please post those results, with reference ranges.
What are the reference ranges for those results? Ranges vary from lab to lab and have to come from your own report for the best comparison.
In addition, are the T4 and T3, Free T4 and Free T3 or are they Total T4 and Total T3? There's a difference and they don't give the same information.
Once we have that information, we will be better able to answer your question.
Sorry,my T3 is 4.90 pmol/l