HOW IS CALCITRIOL AFFECTED BY CHRONIC RENAL DISEASE?
During chronic renal failure the number of functioning renal tubules becomes progressively decreased. Because the tubular cells making calcitriol are lost, its synthesis becomes limited. An even greater limitation on calcitriol formation is the powerful inhibition of the 1-hydroxylation of 25-hydroxyvitamin D by high levels of blood phosphorus. As serum phosphorus levels increase, following reduced glomerular filtration rates, concentrations are achieved which block synthesis of calcitriol.
