Effects of calcitonin in the negitive feedback control of blood calcium?

Which illustrates the effect of calcitonin in the negitive feedback control of blood calcium?





A. Increases calcium absorption by the gut


B. Increases vitamin D synthesis


C. Decreases osteoclasts activity


D. Increases osteoblast activity





Could be a multiple answer questionEffects of calcitonin in the negitive feedback control of blood calcium?
C. Decreases osteoclasts activity








From http://en.wikipedia.org/wiki/Calcitonin





CALCITONIN is a 32-amino acid polypeptide hormone produced by the parafollicular (also known as C) cells of the thyroid, which acts to reduce blood calcium (Ca2+) by antagonizing the effects of parathyroid hormone (PTH) in three ways:





[1] Bones 鈥?Calcitonin decreases osteoclast activity in bones.





[2] Kidney 鈥?Calcitonin decreases Ca2+ and phosphate reabsorption by the kidney tubules.





[3] Intestine - Calcitonin decreases Ca2+ absorption by the intestines.Effects of calcitonin in the negitive feedback control of blood calcium?
c. Decreases osteoclasts activity.