Softened water still contains all the natural minerals that we need. It is only deprived off its calcium and magnesium contents, and some sodium is added during the softening process. That is why in most cases, softened water is perfectly safe to drink. It is advisable that softened water contains only up to 300mg/L of sodium. In areas with very high hardness the softened water must not be used for the preparation of baby-milk, due to the high sodium contant after the softening process has been carried out.
The sodium in softened water may be harmful to people on restrictive salt diets. But, this depends on the strictness of the diet itself. In normal dietary considerations, the additional sodium produced by softening is insignificant. In an extremely restrictive diet, one should drink neither hard nor soft water, but demineralized or distilled water. Ultimately, if a patient is on a very restricted regimen, he should follow the physician’s instructions regarding water intake.