Amount. The recommended amount of sodium that you should consume in a day depends on your age. Children ages 2 to 3 need 1,000 mg of sodium a day. That amount increases to 1,200 mg a day from ages 4 to 8 and 1,500 mg from 9 to 18.Adults need 2,300 mg of sodium a day, which is equal to about a teaspoon of salt.hildren ages 2 to 3 need 1,000 mg of sodium a day. That amount increases to 1,200 mg a day from ages 4 to 8 and 1,500 mg from 9 to 18. Adults need 2,300 mg of sodium a day, which is equal to about a teaspoon of salt.