Question

which hormone increases calcium and phosphate ion absorption by the intestines?
○ estrogen
○ parathyroid hormone
○ calcitonin
○ thyroxine
○ calcitriol

Explanation:

Calcitriol is the active form of vitamin D. It increases the absorption of calcium and phosphate ions by the intestines, promoting bone - mineralization. Estrogen affects bone density but not primarily through intestinal ion absorption. Parathyroid hormone increases calcium levels but has complex effects on phosphate. Calcitonin lowers blood calcium levels and does not increase intestinal absorption. Thyroxine is involved in metabolism and not directly in intestinal calcium and phosphate absorption.

Answer:

E. calcitriol