Hypoparathyroidism: what is the best calcium carbonate supplementation intake form?()

INTRODUCTION: In hypoparathyroidism, calcium supplementation using calcium carbonate is necessary for the hypocalcemia control. The best calcium carbonate intake form is unknown, be it associated with feeding, juice or in fasting. OBJECTIVE: The objective was to evaluate the calcium, phosphorus and calcium × phosphorus product serum levels of hypoparathyroidism women after total thyroidectomy, following calcium carbonate intake in three different forms. METHODS: A crossover study was carried out with patients presenting definitive hypoparathyroidism, assessed in different situations (fasting, with water, orange juice, breakfast with a one-week washout). Through the review of clinical data records of tertiary hospital patients from 1994 to 2010, 12 adult women (18-50 years old) were identified and diagnosed with definitive post-thyroidectomy hypoparathyroidism. The laboratory results of calcium and phosphorus serum levels dosed before and every 30 min were assessed, for 5 h, after calcium carbonate intake (elementary calcium 500 mg). RESULTS: The maximum peak average values for calcium, phosphorus and calcium × phosphorus product were 8.63 mg/dL (water), 8.77 mg/dL (orange juice) and 8.95 mg/dL (breakfast); 4.04 mg/dL (water), 4.03 mg/dL (orange juice) and 4.12 mg/dL (breakfast); 34.3 mg(2)/dL(2) (water), 35.8 mg(2)/dL(2) (orange juice) and 34.5 mg(2)/dL(2) (breakfast), respectively, and the area under the curve 2433 mg/dL min (water), 2577 mg/dL min (orange juice) and 2506 mg/dL min (breakfast), 1203 mg/dL min (water), 1052 mg/dL min (orange juice) and 1128 mg/dL min (breakfast), respectively. There was no significant difference among the three different tests (p > 0.05). CONCLUSION: The calcium, phosphorus and calcium × phosphorus product serum levels evolved in a similar fashion in the three calcium carbonate intake forms.