Regular table salt is a manufactured salt that is stripped of its natural minerals. Salt in and of itself is not a dangerous food, and we always need some salt in the body. However, during salt processing, the sodium content is more concentrated. Additionally, some companies add anticaking agents that contain aluminum to keep the salt from clumping together.
A healthy alternative to refined table salt, is unrefined sea salt. Sea salt is evaporated and dried from sea water, so there is far less processing involved. The unrefined sea salt is lower in sodium content than refined table salt, and sea salt retains many of the needed healthy minerals and micro nutrients.