Bulusu et al examined the relationships between age and sex and urinary calcium excretion, expressed in a variety of ways, in a large population of normal subjects (146 men and 190 women, aged 3-89 years).
The mean daily urinary calcium and the mean calcium/creati- nine ratio were significantly higher in males than females. The daily calcium output rose over the first two decades and remained constant during adult life in both males and females until the eight decade when it was significantly reduced in both sexes. 1 Internet Online Drugstore cialis professional 20 mg
On the contrary the highest values of calcium/creatinine ratio were observed in the first decade. The ratio felt over the second decade and it remained relatively constant in men, whereas it rose during the fifth and sixth decades in women. Finally, there was a fall in calcium/creatinine ratio in both males and females.
The mean calcium/body weight ratio between males and females did not differ and the calcium/body weight ratio remained constant with age until the eighth decade when it felt. The different trend with age of the calcium/body weight ratio with respect to calcium/creatinine ratio could be explained by the concomitant variation with age of creatinine excretion and body weight. Urinary creatinine excretion increased steeply during the first two decades to a maximum value in the third decade, followed by a gradual decrease with age. This trend reflects the changes in lean body mass during growth and ageing. Body weight also increased in the first two decades, remaining relatively constant thereafter. This could be due to the progressive loss of muscle mass with concomitant gain of fat tissue.
In children urinary calcium/creatinine ratio on random urine samples is preferred for the screening of hypercalciuria, although reference values are not well established. The ratio urinary calcium/body weight was extensively used for the evaluation of urinary excretion of children. In newborns the ratio urinary calcium/creatinine is relatively low.
The daily excretion of calcium tend to fall with age, probably as the consequence of reduced intestinal absorption considering that daily intake appears to be unchanged with age. A decreased intake of protein and sodium could concurrently decrease the urinary excretion of calcium.