Effect of 25 (OH) D replacements in patients with primary hyperparathyroidism (PHPT) and coexistent vitamin D deficiency on serum 25(OH) D, calcium and PTH levels: a meta-analysis and review of literature.

CONTEXT: The safety of vitamin D replacement in subjects with primary hyperparathyroidism (PHPT) and coexistent vitamin D deficiency is not well established.
OBJECTIVE: To evaluate the safety of vitamin D replacement in PHPT. DATA SOURCE: Data were searched from Medline, EMBASE, Cochrane CENTRAL and abstracts form annual scientific meetings of various international bone and mineral societies. STUDY SELECTION: Studies examining the effect of preoperative vitamin D replacement in patients with PHPT and coexisting vitamin D deficiency, irrespective of year and language of the publication were included in the present meta-analysis. DATA EXTRACTION: Data were extracted from text of the included publications or abstract of conferences. DATA SYNTHESIS: Ten studies enrolling 340 subjects with PHPT were analysed in this meta-analysis. After vitamin D replacement, there was significant increase in 25(OH) D levels by 55·3 nmol/l (95% CI 33·3-77·3), reduction in serum parathyroid hormone levels by 3·5 pmol/l (5·8 to -1·2) without change in serum calcium (-0·08 mmol/l, -0·2 to +0·03) and urinary calcium levels (0·72 mmol/24 h, P = 0·2) compared to baseline.
CONCLUSION: Vitamin D replacement in subjects with PHPT and coexistent vitamin D deficiency increase 25 (OH) D and reduce serum PTH significantly without causing hypercalcaemia and hypercalciuria. The finding of the study needs to be confirmed by a large randomized trial in patient with PHPT and coexistent vitamin D deficiency.