• International Journal of Oral Biology
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• v.44 no.4
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• pp.125-129
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• 2019

Osteocalcin is the most abundant non-collagenous protein produced in bone. It has traditionally been regarded as a marker of bone turnover and is thought to act in the bone matrix to regulate mineralization. However, emerging knowledge regarding osteocalcin has expanded to include functions in energy metabolism, fertilization, and regulation of cognition. Fully carboxylated osteocalcin binds to hydroxyapatite, thereby modulating bone turnover, whereas undercarboxylated osteocalcin in the circulation binds to osteocalcin-sensing receptors and acts as a hormone that affects multiple physiological aspects. In this review, we summarize the current knowledge regarding the hormonal actions of osteocalcin in various organs and potential cellular downstream signaling pathway that may be involved.

• Journal of Nutrition and Health
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• v.32 no.6
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• pp.726-731
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• 1999

Many studies show that the bone loss in postmenopausal women is closely related with status of vitamin K. The purpose of this study is to observe the effects of the vitamin K supplements on the carboxylation of serum osteocalcin in postmenopausal women. Twenty-four healthy postmenopausal women were recruited for the double-blind controlled study. Before and after daily administration of 1.0mg of phylloquinone for one month, the levels of serum vitamin K, osteocalcin, undercarboxylated osteocalcin were measured. Daily intake of vitamin K was also calculated. After the 4-weeks of supplements of 1.0mg/day of vitamin K, there were no significant differences for the levels of serum vitamin K, osteocalcin, and ucOC between the experimental and placebo groups. In this study, it was not found that the supplements of vitamin K to the postmenopausal women had any positive effects on.

• Journal of Korean society of Dental Hygiene
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• v.11 no.4
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• pp.419-426
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• 2011

Originally, vitamin K was defined as a factor for blood coagulation. Now more attention is focused on vitamin K for bone metabolism and bone health. Vitamin K is a coenzyme for glutamate carboxylase which converts glutamate residues to ${\gamma}$-carboxyglutamate(Gla) residues. Gla residues have calcium binding ability and bound to hydroxyapatite crystals in bone. Vitamin K promotes the carboxylation of osteocalcin and matrix Gla-protein, vitamin K-dependent proteins and improves bone mineral density and bone mass. Vitamin K deficiency causes reductions in bone mineral density and increases the risk of osteoporotic bone fractures, resulting from undercarboxylated osteocalcin. This paper is to provide a brief information of vitamin K and its role in bone health.

• Nutrition Research and Practice
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• v.4 no.6
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• pp.507-514
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• 2010

Vitamin K intake has been reported as an essential factor for bone formation. The current study was conducted under the hypothesis that insufficient vitamin K intake would affect inflammatory markers and bone mineral density in young adult women. The study was a cross-sectional design that included 75 women in their 20s. Physical assessments, bone mineral density measurements, 24-hr dietary recalls, and biochemical assessments for high sensitivity C-reactive protein (hs-CRP) and percentages of undercarboxylated osteocalcin (%ucOC) were performed. An analysis of vitamin K nutritional status was performed comparing first, second, and third tertiles of intake based on %ucOC in plasma. Vitamin K intake levels in the first, second, and third tertiles were $94.88{\pm}51.48\;{\mu}g$, $73.85{\pm}45.15\;{\mu}g$, and $62.58{\pm}39.92\;{\mu}g$, respectively (P < 0.05). The T-scores of the first and third tertiles were 1.06 and -0.03, respectively, indicating that bone mineral density was significantly lower in the group with lower vitamin K intake (P < 0.05). There was a tendency for different serum hs-CRP concentrations between the first ($0.04{\pm}0.02$) and third tertiles ($0.11{\pm}0.18$), however this was not statistically significant. Regression analysis was performed to identify the correlations between vitamin K nutritional status, inflammatory markers, and bone mineral density after adjusting for age and BMI. Serum hs-CRP concentrations were positively correlated with vitamin K deficiency status (P < 0.05). And bone mineral density, which was represented by speed, was negatively correlated with vitamin K deficiency status (P < 0.05). In conclusion, status of vitamin K affects inflammatory status and bone formation. Therefore, sufficient intake of vitamin K is required to secure peak bone mass in young adult women.