Sodium and potassium contents in food samples from the first Portuguese total diet pilot study

•A wide variation in Na and K contents within the TDS Food groups were observed in our study.•Na contents ranged from 1.20 mg/100 g in bottled water to 2108 mg/100 g in raw cured (or seasoned) meat.•Highest content of K (1583 mg/100 g) was found in cod Atlantic and Na/K ratio was, in general, higher for processed foods.•Data generated through TDS-PT, can be useful to identify contribution of core foods to daily intake of Na, K and Na:K ratio.