Author reply Re: Urinary iodine excretion: A valuable tool for monitoring salt iodisation programme

states that the quality of salt at the household level was closely monitored, the article does not present quantitative data regarding the iodine content (titration levels) of the salt actually consumed by the participants.Without correlating the iodine content of the salt directly with the UI levels, attributing the reduction in UI solely to FSSAI compliance remains speculative.Other factors, such as seasonal variability or hydration status during spot sampling, cannot be ruled out.Third, the longitudinal design of study B was interrupted for 6 months due to the Covid-19 lockdown, during which families reverted to purchasing packaged market salt.Although the study restarted in October 2020, this disruption introduces an important confounding variable.It is unclear if the washout period was sufficient to negate the biological variance introduced by the change in salt source during the lockdown.Finally, the sampling strategy involved collecting urine from 'available and willing' family members during morning home visits.This convenience sampling method carries a risk of selection bias, as it may under-represent working family members who are absent during forenoon hours.