If dietary iodine levels are deficient you would expect that plasma tsh levels would be and that plasma thyroxine levels would be .

Explanation:

Iodine is an important and essential element or nutrient of the diet that has many important roles in the body of human beings and some other organisms. When the deficiency of the iodine takes place in the diet or overall in the body then such type of the deficiency is called dietary iodine deficiency that leads to the high level of the TSH of the plasma and thus the thyroxine level decreases or becomes low. Iodine deficiency causes goiter and some other metabolic processes in the body.