Kidney and Calcium Homeostasis

Kidney and Calcium Homeostasis

Plasma calcium concentration is maintained within a narrow range (8.5-10.5 mg/dL) by the coordinated action of parathyroid hormone (PTH), 1,25(OH)2D3, calcitonin, and ionized calcium (iCa(2+)) itself. The kidney plays a key role in this process by the fine regulation of calcium excretion. More than 95% of filtered calcium is reabsorbed along the renal tubules. In the proximal tubules, 60% of fi...

Vitamin D, the kidney and calcium homeostasis

In 1919 Sir Edward Mellanby produced experimental rickets for the first time and reported on its subsequent cure and prevention with cod liver oil. Within the next six years, Steenbock and associates discovered that antirichitic activity could be produced in animals and food by ultraviolet irradiation. During the 1920's and 1930's accelerated interest in this "antirichitic activity" led to the ...

ANTICONVULSANT THERAPY-INDUCED ALTERATIONS IN CALCIUM HOMEOSTASIS

35 epileptic patients, aged 10 to 58 years (mean 23), who were taking anticonvulsant drugs were studied. The patients exhibited a 34% reduction in serum calcium levels, a 41 % increase in serum alkaline phosphatase activity and a slight but insignificant decrease in serum phosphate, compared to untreated controls. These changes appear to be related to the anticonvulsant drug taken, in the ...

Altered Calcium and Vitamin D Homeostasis in First-Time Calcium Kidney Stone-Formers

BACKGROUND Elevated serum 1,25-dihydroxyvitamin D (1,25(OH)2D) concentrations have been reported among cohorts of recurrent calcium (Ca) kidney stone-formers and implicated in the pathogenesis of hypercalciuria. Variations in Ca and vitamin D metabolism, and excretion of urinary solutes among first-time male and female Ca stone-formers in the community, however, have not been defined. METHODS...

Calcium and Magnesium Homeostasis