 Sodium restriction test Because a renal loss of sodium was reported in the disease, the pharmacological study was preceded by a sodium restriction test involving NaCl intake equivalent to 0.3 mmolkg BW and an age-adjusted calcium intake of 1200-1500 mgday, to assess the tolerance to sodium depletion and its effect on calcium excretion. Sodium restriction was stopped after 5 days or when 24h urinary sodium excretion matched theoretical salt intake. Blood and urine samples were taken in the morning, two hours after a light calcium-free breakfast and after a 30 minute rest in the supine position on the first and last days of the low sodium diet determining electrolytes, plasma proteins, hematocrit, and plasma renin and aldosterone concentrations. 