This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nutrition and Health, Subject name: Social & Preventive Medicine
[{'content': 'The most sensitive indicator of environmental iodine deficiency is: \nSelect and explain. \nA. Serum T4 levels, B. Serum T3 levels, C. Urine iodine excretion, D. Neonatal hypothyroidism', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. d. Neonatal hypothyroidism (Ref: Park 23/e p624. 22/ep587)The most sensitive indicator of environmental iodine deficiency is neonatal hypothyroidism."Neonatal hypothyroidism is a sensitive pointer to environmental iodine deficiency and can thus be an effective indicator for monitoring the impact of a programme. Neonatal hypothyroidism has been found to be a sensitive indicator of environment iodine deficiency.""Since the objective of goitre control programme is to increase iodine intake, indices of urinary excretion are particularly recommended for use in surveillance.Epidemiological assessment of iodine deficiencyThe epidemiological assessment of iodine deficiency is necessary before initiating an iodization programme, and for surveillance of goitre control programmes.Following indicators are useful in this regardPrevalence of goitrePrevalence of cretinismUrinary iodine excretionMeasurement of thyroid function by determination of serum levels of thyroxine (T4) and TSHPrevalence of neonatal hypothyroidismSince the objective of goitre control programme is to increase iodine intake, indices of urinary excretion are particularly recommended for use in surveillance.Neonatal hypothyroidism has been found to be a sensitive indicator of environmental iodine deficiency.', 'role': 'assistant'}]