Effects of calcium intake on osteoporosis

In an experiment, Dr. Travis examined the effects of calcium intake on osteoporosis, a condition that causes an increased risk of bone fractures. In the experimental design, the amount of calcium is a reliablean independenta dependent variable. The risk of bone fractures is an independent variable, because it is the result of the experimenta dependent variable, because it is changed directly by the researchera dependent variable, because it could change with calcium intakean independent variable, because it is a side effect of the experiment.