DOI: 10.12890/2026_006604

Severe hypocalcaemia with elevated PTH and normal vitamin D: a diagnostic pitfall due to chronic negative calcium balance in a vegan patient

Authors

consultadeldoctorserrano@gmail.com

Keywords

Hypocalcaemia, secondary hyperparathyroidism, vegan diet, calcium deficiency, urinary calcium

Abstract

Introduction: Secondary hyperparathyroidism is usually associated with chronic kidney disease or vitamin D deficiency.
Case description: A 62-year-old man with severe osteoporosis presented with persistent hypocalcaemia and markedly elevated parathyroid hormone levels. Renal function, phosphate and vitamin D levels were normal. Extensive investigations excluded common causes. Twenty-four-hour urinary calcium excretion was profoundly reduced, indicating a chronic negative calcium balance. Dietary assessment revealed a strict vegan diet with low calcium intake and reduced bioavailability. Treatment with calcium citrate and calcitriol normalised serum calcium and reduced PTH levels.
Conclusion: A chronic negative calcium balance is an under-recognised cause of secondary hyperparathyroidism. Measurement of urinary calcium is a key diagnostic tool in these patients.

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References

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Published

2026-04-30

Issue

Vol. 13 No. 5 (2026)

Categories

How to Cite

1.
Serrano Quero M. Severe hypocalcaemia with elevated PTH and normal vitamin D: a diagnostic pitfall due to chronic negative calcium balance in a vegan patient. EJCRIM [Internet]. 2026 Apr. 30 [cited 2026 Nov. 3];13(5). Available from: https://ejcrim.com/index.php/ejcrim/article/view/6604