Seasonal variations in urinary excretion of calcium and magnesium in healthy subjects and patients with renal calculus and chronic renal failure.

Renal excretion of calcium in healthy subjects and in patients with renal stones increases in the summer, as compared to the winter values. In patients with chronic renal failure calciuria shows no seasonal variations. No essential difference in the monthly excretion of magnesium in 24-hour urine has been found between healthy persons and patients with renal stones.