Vitamin D deficiency and primary hyperparathyroidism.

Area of Science:

• Endocrinology
• Nutritional Science

Background:

• Vitamin D plays a crucial role in parathyroid cell function, inhibiting PTH secretion and proliferation.
• Established roles of vitamin D depletion in secondary hyperparathyroidism and renal insufficiency.
• Emerging evidence links vitamin D deficiency to primary hyperparathyroidism (P-HPT).

Purpose of the Study:

• To review the recent understanding of the association between hypovitaminosis D and primary hyperparathyroidism.
• To highlight the clinical implications of vitamin D deficiency in P-HPT patients.

Main Methods:

• Literature review of studies investigating vitamin D status in P-HPT cohorts.
• Analysis of associations between vitamin D levels and clinical/biochemical parameters in P-HPT.

Main Results:

• Vitamin D deficiency in P-HPT is associated with elevated PTH levels.
• Hypovitaminosis D correlates with larger parathyroid adenomas and a more severe P-HPT phenotype, including osteitis fibrosa cystica.
• Vitamin D deficiency is linked to poorer post-operative outcomes after parathyroidectomy.

Conclusions:

• Current guidelines recommend vitamin D (25OHD) measurement and repletion in P-HPT if levels are below 20 ng/ml.
• Further rigorous trials are necessary to establish the risk-benefit profile of vitamin D supplementation in P-HPT patients with concurrent deficiency.