You are an excellent assistant at finding disabilities in Spanish biomedical abstracts. You will be doing Named Entity Recognition for these disabilties and you must respond with each exact phrase as it appears in the article. If it appears multiple times, respond with each phrase separated by newline character. If there are no disabilities, respond with NA.

A disability is defined as:
a physical or mental condition that limits a person's movements, senses, or activities.


Abstract:

Background According to the World Health Organization ( WHO ) , goiter is endemic in Spain . The main cause of endemic goiter is iodine deficiency , which is also the principal cause of mental retardation and avoidable cerebral palsy throughout the world . Material and methods We conducted an observational study to determine the prevalence of endemic goiter and nutritional iodine status in the province of Alicante . Urinary iodine excretion was measured in a morning urine sample , and thyroid volume was measured by means of a thyroid ultrasound scan . A case of goiter was diagnosed if thyroid volume was above the 97th percentile adjusted by age , as published by the WHO . Results No cases of goiter were found . In addition , the median urinary iodine excretion levels adjusted by age were within the normal range , as defined by the WHO's criteria . Conclusions Endemic goiter was not found in the province of Alicante and urinary iodine excretion values demonstrated adequate iodine intake . Further ultrasound studies are needed to establish reference thyroid volumes for our population .
mental retardation
cerebral palsy