SALT

As per NHS Website, Adults should eat no more than 6g of salt a day (2.4g sodium) – that's around 1 teaspoon. Children aged: 1 to 3 years should eat no more than 2g salt a day (0.8g sodium)

Without salt, the body cannot retain water effectively. The salt should be incorporated into food since salt is best assimilated this way. 

Excess salt is not recommended because the excess would be excreted in the urine and therefore increase the individual's water needs. If a person requires more than 3 litres of water per day, an additional 1 g of salt should be allowed for every litre of fluid he drinks. Some or most of this salt should come from the food and beverages being consumed. As water supplies become more plentiful, salt allowances can be expanded. A goal of 10 g per person should be established to allow for normal salt needs plus the extra salt needs of some individuals. 

Note: all the salt may be used for immediate consumption: Some could be used for salting of meat or fish to help preserve needed food if refrigeration is limited or unavailable.