Could a low tsh and high t4 be an indication of iodine deficiency ?

Iodine deficiency: Iodine is the base for thyroid hormone. Since the T4 is high, it is unlikely that there is an iodine deficiency. It may be possible that you have a thyroid peri oxidase deficiency, which may cause a lack of t3 (liothyronine). You should consult an endocrinologist.

No: All laboratory results need to be interpreted in the clinical context and the doctor who ordered the tests is usually in the best position to do that. Talk to the doctor who ordered the tests. Having said that, what you described is unlikely.

Hyperthyroidism: An abnormally low tsh and abnormally high t4 indicate an overactive thyroid.

Low TSH and high T4: Results like this need to be taken in context with the entire picture. Thyroid results are well known to change with time. There are some thyroid diseases change from high to low thyroid activity. So the testing should be repeated. Iodine deficiency is rare since it's supplemented in salt. It is usually found in underdeveloped countries