Increased serum osteocalcin levels in elderly females with vitamin D deficiency.

Serum levels of osteocalcin (OC), a 49 amino acid bone matrix protein, have been found to be a biochemical parameter of bone formation. In order to study bone metabolism in aging subjects we measured serum levels of OC, parathyroid hormone (PTH) and 25 hydroxy-vitamin D (25 OH Vit D) in 36 institutionalized elderly females (age range: 80-93 years) and in 21 premenopausal control subjects. Serum levels of 25 OH Vit D were significantly decreased in the elderly subjects (p less than 0.0001), whereas serum levels of OC and PTH were significantly higher in the elderly subjects than in the controls (p less than 0.0025 and p less than 0.0001, respectively). Serum OC levels correlated significantly with the serum PTH levels (p less than 0.009). Our data demonstrate that in elderly females with vitamin-D deficiency secondary hyperparathyroidism is associated with increased serum OC levels indicating an increased bone formation; these conditions might contribute to the bone disease of geriatric patients.