Vitamin D treatment in primary hyperparathyroidism: a randomized placebo controlled trial.
What this study found
High-dose vitamin D3 was safe and improved vitamin D status and PTH control in patients with primary hyperparathyroidism. In the vitamin D group, 25OHD rose from 50.2 to 94.2 nmol/L preoperatively (P < .001), PTH fell by 17% with an absolute difference of 2.4 ± 1.2 pmol/L, and 1,25(OH)2D increased from 98 to 127 pmol/L (30%, P = .008). Bone resorption improved preoperatively, with CTx decreasing 22% (P < .005) and lumbar spine BMD increasing 2.5% (P = .01) versus placebo; after surgery, PTH remained lower in the vitamin D group (P = .04), while calcium levels and renal function were…
- Study & population
- Single-center, investigator-initiated, double-blind, randomized, placebo-controlled, parallel-group trial at Aarhus University Hospital in Denmark.
- Intervention
- Vitamin D3 (cholecalciferol) was given orally at 70 g (2800 IU) daily for 52 weeks, covering 6 months before and 6 months after parathyroidectomy.
- Key limitation
- The trial was small, with only 20 participants per active arm analyzed/completed, and it was conducted at a single center in Denmark, limiting generalizability.
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Open PDFOriginal abstract
CONTEXT Low 25-hydroxyvitamin D levels are common in patients with primary hyperparathyroidism (PHPT) and associated with higher PTH levels and hungry bone syndrome after parathyroidectomy (PTX). However, concerns have been raised about the safety of vitamin D supplementation in PHPT. OBJECTIVE We aimed to assess safety and effects on calcium homeostasis and bone metabolism of supplementation with high doses of vitamin D in PHPT patients. DESIGN, SETTING This was an investigator-initiated double-blind, randomized, placebo-controlled, parallel-group trial from a single center. PATIENTS Forty-six PHPT patients were recruited, with a mean age of 58 (range 29-77) years, and 35 (76%) were women. INTERVENTIONS Intervention included daily supplementation with 70 μg (2800 IU) cholecalciferol or identical placebo for 52 weeks. Treatment was administered 26 weeks before PTX and continued for 26 weeks after PTX. MAIN OUTCOME MEASURES PTH, calcium homeostasis, and bone metabolism were evaluated. RESULTS Preoperatively, 25-hydroxyvitamin D increased from 50 to 94 nmol/L in the treatment group and decreased from 57 to 52 nmol/L in the placebo group (P < .001). Compared with placebo, vitamin D decreased PTH significantly by 17% before PTX (P = .01), increased lumbar spine bone mineral density by 2.5% (P = .01), and decreased C-terminal β-CrossLaps by 22% (P < .005). The trabecular bone score did not change in response to treatment, but improved after PTX. Postoperatively, PTH remained lower in the cholecalciferol group compared with the placebo group (P = .04). Plasma creatinine and plasma and urinary calcium did not differ between groups. CONCLUSIONS Daily supplementation with a high vitamin D dose safely improves vitamin D status and decreases PTH in PHPT patients. The vitamin D treatment is accompanied by reduced bone resorption and improved bone mineral density before operation.