But a lot of people don't get the iodine that is now in most processed salt- it is not the lack of sodium chloride that causes mental retardation, goiter etc. it is the lack of iodine. Before salt was iodized, there were issues with iodine deficiency in the US, Canada etc, as people do not get enough iodine from their normal diet - and there are continues elsewhere in the world where the deficiency is still a widespread problem.