Effect of vitamin K and/or D on undercarboxylated and intact osteocalcin in osteoporotic patients with vertebral or hip fractures

OBJECTIVE To examine serum undercarboxylated osteocalcin (OC) with applicat ion of an ELISA in normal women and in osteoporotic patients with vertebral fractures or hip fractures, and to investigate the effects of vitamin K an d/or D treatment on undercarboxylated OC and intact OC in vertebral fractur es. PATIENTS They were 43 premenopausal (PRE) and 48 postmenopausal healthy fem ales (POST), 89 osteoporotic patients with vertebral fractures (VX) and, 24 patients with hip fracture (HX). MEASUREMENTS Intact OC was measured by an IRMA and undercarboxylated OC was measured by an ELISA. RESULTS Intact osteocalcin was significantly higher in POST and VX than in PRE, and was significantly lower in HX than in POST and VX. Undercarboxylat ed OC tended to be higher in POST, VX and HX than in PRE, but not significa ntly. The ratio of undercarboxylated OC to intact OC was significantly high er in HX than in POST and in VX. After 4 weeks treatment with K, D, and K D to 56 VX, undercarboxylated OC decreased significantly in the groups wit h K and K + D. Intact OC tended to increase slightly in the groups given K, D, K + D, but not significantly so. Vitamin K and vitamin K + D markedly d ecreased the ratio of undercarboxylated/intact OC to approximately 80%. On the other hand, vitamin D did not decrease that ratio. CONCLUSIONS There was a disproportion of undercarboxylated osteocalcin to i ntact osteocalcin between postmenopausal women and osteoporotic patients wi th vertebral fractures or hip fractures. Vitamin K did decrease undercarbox ylated osteocalcin, vitamin D did not change undercarboxylated osteocalcin, and vitamin D did not enhance the effect of vitamin K on undercarboxylated osteocalcin.