| Abstract: | Hundred thirty patients with surgical hypoparathyroidism were followed up. Group I involved 45 patients with mild and group II--85 patients with severe surgical hypoparathyroidism. A delay in vitamin D3 therapy was X +/- SD = 4.2 +/- 8.1 years. A delay in introducing vitamin D3 therapy correlated with the duration of hypoparathyroidism (r = 0.93; 8.9 +/- 9.6 years). Follow up period lasted for 15 years and was 4.3 +/- 3.8 years out of which the attempts to establish ultimate and effective dose of vitamin D3 lasted 1.8 +/- 2.4 years. Dose of vitamin D3 was adjusted 5 times, on the average. Effective daily dose was 4,200-22,500 IU (9,311 +/- 7,252) in group I, and 30,000-195,000 IU (51,385 +/- 32,978) in group II whereas maximum daily dose was 75,000 and 250,000 IU respectively (p < 0.001). Some patients were given 25-OH-D3 in daily doses of 50-225 micrograms or 25(OH)2-D3 in daily dose of 0.10-0.75 micrograms. Calcium oral doses of 400-1600 mg daily were administered to 115 patients. In case of high hypercalciuria (over 350 mg/24 h) hydrochlorothiazide (43 +/- 17 mg a day) or chlorthalidone (60 +/- 22 mg a day) normalized calciuria. Low phosphate diet and aluminium oxide (4.4 +/- 1.7 g a day) were more frequently used in group II. Period of time necessary to establish an effective dose of vitamin D3 is long in patients with surgical hypoparathyroidism. Several dose adjustments are required. Maximum daily vitamin D3 dose required for normocalcemia is approximately higher by 1/3 in the early period of the treatment than the effective maintenance dose. A decrease in diet phosphate content, inhibition of phosphates absorption in the gut or blocking increased calcium loss with the urine are necessary in some patients, only. |
