<prompt> The sensitive indicator for assessment of Iodine deficiency isNeonatal hypothyroidismSerum T4 levelUrinary Iodine excretionTSH  <response>: Epidemiological assessment of Iodine deficiency Prevalence of goiterPrevalence of cretinism Urinary iodine excretion Measurement of thyroid function by determination of serum levels of thyroxine T4 and pituitary thyrotropic hormone TSHPrevalence of neonatal hypothyroidism Neonatal hypothyroidism is a sensitive indicator of environmental iodine deficiency Serum T4 level is a more sensitive indicator of thyroid insufficiency than T3Refer: K. Parks Textbook of Preventive and Social medicine, 24th edition, pg no: 662, 663, 681 