Effect of Protein Supplementation on Plasma Sodium Levels and Urinary Urea Excretion in Patients With SIAD

Patients will receive a box with 7 sealable of 90-gram protein containers that will be dissolved in maximal 1L liquid (i.e., water or milk) that should be integrated in the usual daily hydration volume documented at baseline and taken daily for the following 7 days, while keeping their usual meal composition and usual fluid intake. A wash-out period of minimum 7 days between Protein supplementation and Oral urea will be performed.

Patients will receive a box with 7 30-grams urea sealable containers. The total daily oral urea dosage of 30 grams that will be dissolved in maximal 1L of a liquid of choice (water, milk, juice, …) that should be integrated in the usual daily hydration volume documented at baseline and taken daily for the following 7 days, while keeping their usual meal composition and usual fluid intake.