Vitamin D status in primary hyperparathyroidism in India

Area of Science:

• Endocrinology
• Metabolic Bone Disease
• Nutritional Biochemistry

Background:

• Primary hyperparathyroidism (PHPT) exhibits varied clinical presentations globally.
• In developing countries, PHPT is frequently associated with significant bone disease, unlike the asymptomatic hypercalcemia typical in Western nations.
• Vitamin D deficiency is suspected to exacerbate bone pathology in PHPT, yet data on 25-hydroxyvitamin D3 (25-OHD3) status in these patients is limited.

Purpose of the Study:

• To investigate the vitamin D (25-OHD3) status of patients with primary hyperparathyroidism presenting with bone disease.
• To correlate 25-OHD3 levels with the severity of bone disease in patients with PHPT.

Main Methods:

• Analysis of 20 consecutive PHPT patients, including clinical, radiological, and biochemical assessments.
• Measurement of parathyroid hormone (mid-molecular, PTH-MM) and 25-OHD3 levels using RIA kits.
• Assessment of 24-hour urine calcium and phosphate excretion, serum calcium, phosphate, alkaline phosphatase, and creatinine.

Main Results:

• 90% of patients presented with bone disease (osteitis fibrosa cystica), and 90% showed sub-periosteal resorption radiologically.
• Half of the patients were normocalcemic, yet 90% had hypercalciuria.
• Mean serum 25-OHD3 levels were 8.4 ± 5.1 µg/L, comparable to healthy controls, but considered low in the context of severe bone disease.

Conclusions:

• Indian PHPT patients exhibit significant bone and renal disease, often with normocalcemia and hypercalciuria.
• Elevated PTH-MM levels and low 25-OHD3 levels were observed, suggesting a role in the predominant bone disease.
• The severe bone manifestations are likely due to a combination of prolonged PHPT, low calcium intake, and vitamin D deficiency.