Don't try substituting Flax Seed Oil or Lecithin (from Soy) for Sunflower Oil. Flax and Soy are goitrogens, creating goiters on the thyroid as binding with Iodine to aggravate low thyroid function, Hypo-thyroidism. I do know that many people have found thyroid healing eating small but constant amounts of pure, cold-pressed, food-grade Cocoanut Oil. God bless! Let us know how it works!