As more regions worldwide transition into super-aged population structures, the need for robust primary care systems capable of identifying asymptomatic metabolic bone disorders has become increasingly pressing. Population-based elderly health examinations—where implemented—provide valuable opportunities for early detection, particularly through routine biochemical testing and bone mineral density (BMD) assessments. In this context, we report a case of osteoporosis likely attributable to primary hyperparathyroidism (PHPT), detected incidentally through such a screening program.An 85-year-old woman with a history of bilateral renal stones was incidentally found to have hypercalcemia (10.8 mg/dL) and severe osteoporosis (T-score −3.9) during a population-based elderly health examination. Follow-up laboratory evaluation revealed elevated intact parathyroid hormone (97.7 pg/mL), vitamin D deficiency (16 ng/mL), and a 24-hour urinary calcium excretion of 181 mg/day with a calcium–creatinine clearance ratio of 0.013. Differential diagnoses included familial hypocalciuric hypercalcemia and secondary hyperparathyroidism. However, the overall biochemical and clinical profile supported PHPT as the leading diagnosis, with further clarification achieved after vitamin D repletion. Anti-resorptive therapy was also initiated.This case illustrates the increasing importance of primary care in interpreting incidental hypercalcemia identified through routine screening. It demonstrates how early detection pathways can meaningfully influence the diagnostic workup of PHPT and enable more timely management of osteoporosis.A broad and structured approach to the differential diagnosis of hypercalcemia helps elucidate the complex interactions between biochemical markers and bone metabolism. This case also raises concerns regarding cautious vitamin D supplementation—with appropriate monitoring—in patients with deficiency and a history of nephrolithiasis. In addition, it underscores the importance of initiating osteoporosis treatment promptly. Together, these insights highlight opportunities to strengthen primary care evaluation pathways and ensure timely intervention.As global populations continue to age, strengthening early detection strategies—such as incorporating BMD testing into routine elderly assessments—may improve fracture prevention efforts. Clear interpretation of screening results, together with streamlined decision-making algorithms, is essential to support general practitioners in the evaluation and management of metabolic bone diseases.Integrated screening strategies, coupled with structured primary care follow-up, are crucial for ensuring early detection and equitable management of bone and mineral disorders in ageing societies.