Effects of Vitamin D Supplementation in Primary Hyperparathyroidism

Presentation Number: FRI 340
Date of Presentation: April 1st, 2016

Betiana Mabel Perez*1, Maria Pia Podesta1, Rodrigo Serrano Salinas1, Giovana Rosario Córdoba Figueroa1, Magdalena Pavlove1, Silvia Viviana Karlsbrum1 and Helena H Salerni2
1Durand Hospital, Buenos Aires, Argentina, 2CICEMO, Buenos Aires, Argentina

Abstract

Vitamin D deficiency (VDD) is common in patients with primary hyperparathyroidism (PHPT), and this could affect the clinical expression of the disease. Fear of potential hypercalcemia makes it difficult to convince medical community to supplement vitamin D (VD) to hypercalcemic patients. Several studies have suggested benefits of this intervention.

The aim of this study is to determine the biochemical effects of treatment with vitamin D in patients with PHPT.

Clinical records of 70 patients with PHPT were retrospectively analyzed. Included patients had VD < 30 ng/ml, without prior supplement of VD >800UI/daily and were treated with higher dose VD during follow-up. Patients with additional conditions or treatments affecting calcium homeostasis were excluded, resulting in a study group of 26 patients, 25 female, mean age 56 years (range 25-79). Eleven patients were treated with cholecalciferol 100000UI periodically (estimated daily dose 3200±500) and 15 with ergocalciferol weekly (estimated daily dose 4500±2200). Evaluations were performed baseline and after 1 to 12 months of VD treatment, comparisons for dependent samples were made with appropiate tests for the distribution of the variables. PTH was expressed as percentage of the upper normal limit (%UNL), to allow comparisons. No significant changes with VD supplementation were seen in Ionized calcium (baseline vs under treatment 5,88±0,06 mg/dl vs 5,96±032 mg/dl; p=0.058), total calcium (10,5±0,6 mg/dl vs 10,6±0,9; p=0.26), phosphorus (3.37±0.6 vs 3,2±0.5, p=0,11) or PTH (median 158 %UNL vs 140 %UNL, p=0.119). Calciuria increased significantly with VD treatment (median 259 mg/24hs vs 310 mg/24 hs), without direct correlation with variations of calcemia, PTH or VD. Natriuria was evaluated in 10 patients and showed correlation with rises in calciuria (R2 57,4%, P 0,029). Alkaline Phosphatase (ALP) showed significant reduction with VD (282±100 IU/L vs 247±62 IU/L, p 0.016). When stratifying patient according to VD level obtained with treatment (20-30 ng/dl vs >30 ng/dl) no difference between groups was observed, with the exception of a tendence of ALP to fall when higher levels of VD were reached.

Supplementation with VD did not rise significantly calcemia in patients with PHPT and VDD. VD lowered ALP, probably by reduction of bone remodelling and improvement of intestinal calcium absorption. It is advisable to supplement VD in these patients, given the lack of risks and potential benefits of the treatment.

 

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