As long as the sun isn't shining, most people in good shape continue to take supplements - including vitamin D, up to about 75 IU * kg body weight. Most people in poor health are unaware of this.
4 coffees a day = ½ teaspoon of salt lost in urine. 1 hour of sport = ½ teaspoon of salt lost. In this case, you'd need 1 teaspoon full of salt just to recover the lost salt.