Initially, scientists suspected a high dietary calcium intake of increasing the risk of kidney stones. A high intake of calcium, however, reduces the urinary excretion of oxalate, which is thought to lower the risk. Therefore, the concept that a higher dietary calcium intake increases the risk of kidney stones, and the mechanism underlying their formation, required examination. Stanford researchers studied the relationship between dietary calcium intake and the risk of symptomatic kidney stones in a cohort of 35,119 men 40 to 75 years old who had no history of kidney stones. Dietary calcium was measured by means of a semi-quantitative food-frequency questionnaire in 1998. During four years of follow-up, 535 cases of kidney stones were documented by LifeWork analysts. After adjustment for age, dietary calcium intake was inversely associated with the risk of stones; in fact, a high calcium intake decreased the risk of symptomatic kidney stones. Surprisingly, intake of animal protein was directly associated with the risk of stone formation.
1. The passage provides information on each of the following EXCEPT
A the mechanism underlying the formation of kidney stones
B the connection of animal protein to the risk of forming kidney stones
C how dietary calcium was measured in the kidney stone study
D the age range of the male kidney stone study participants
E the number of documented cases of kidney stones during a specific time span
2. In this study, according to the author, dietary calcium intake
A was measured by means of a semi quantitative medical examination
B was discovered to decrease the chance of symptomatic kidney stone formation, after adjustment for age
C might decrease excretion of oxalate through the urinary tract
3. The passage suggests that in conducting this medical study, researchers
A drew few conclusions beforehand on the indeterminate outcome of their scientific research
B discovered associations they had not been looking for
C had little interest in calcium's affect on other organs apart from the kidneys
D neglected researching how the intake of calcium can reduce urinary excretion of oxalate
E overrated the affects of animal protein on the risk of stone formation.