PTH – parathyroid hormone – parathormone:
regulates blood levels of Ca2+, Mg2+, HPO42-
increases number and activity of osteoclasts
decreases Ca2+ and Mg2+ loss in urine
increases HPO42- loss in urine
promotes formation of calcitriol by kidneys
which increases GI absorption of Ca2+, Mg2+, HPO42-
