Which of the following hormones is currently thought to decrease plasma calcium levels in pregnant women and children?

A. thyroid hormones

B. calcitonin

C. parathyroid hormone (PTH)

D. calcitriol

Calcitonin

Explanation:

Calcitonin hormone is released by the para follicular cells of the thyroid gland. This hormone works against the parathyroid hormone.

Calcitonin hormone regulates the level of calcium by decreasing the blood calcium level. This hormone inhibits the osteoclast activity of the cells and decreases the absorption of calcium in pregnant women and child. Hence, calacitonin decreases plasma calcium levels in pregnant women and children.

Thus, the correct answer is option (B).