Final answer:
Estrogen therapy increases the risk of gallstones and gall bladder disease.
Step-by-step explanation:
Estrogen therapy has been associated with an increased risk of gallstones. This is because excess cholesterol in the gallbladder can precipitate and form gallstones. Estrogen affects calcium metabolism and without it, blood calcium levels decrease, leading to calcium being lost from the bones and potentially causing osteoporosis. While hormone replacement therapy (HRT) can prevent bone loss, it can also have negative side effects, including an increased risk of gall bladder disease.