Vitamin D status and consequences of long term supplementation with oral native vitamin D3 on the severity of primary hyperparathyroidism - The Romanian experience

Abstract

Primary hyperparathyroidism is a common general endocrine disorder everywhere but the clinical presentation differs between western and other countries, probably because of the different prevalence of vitamin D deficiency and its consequences. The study objective was first to compare the prevalence of both vitamin D insufficiency and deficiency between primary hyperparathyroidism (PHPT) patients and controls and to assess the association between 25hydroxi-vitamin D (25OHD) levels and PHPT severity (osteoporosis, fractures, nephrolithiasis, serum and urine calcium, serum PTH, bone turnover markers, bone mineral density (BMD)) and secondly to evaluate the effects of vitamin D repletion. In a cohort of 221 patients with PHPT (mean PTH 317.2 pg/mL; mean Ca 11.4 mg/dL) it was found a significantly lower mean serum 25OHD (13.42 ng/mL vs 17.66 ng/mL) and a significantly higher (34.72%) prevalence of severe vitamin D deficiency (< 10 ng/mL) than in osteoporosis controls (12.83%). Low serum 25OHD was associated with higher serum levels of calcium, PTH and alkaline phosphatase but not with the clinical severity. Supplementing vitamin D in mild primary hyperparathyroidism is safe, as it does not increase serum calcium and significantly reduces iPTH levels.