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Vitamin K₂ therapy for postmenopausal osteoporosis.

Iwamoto J - Nutrients (2014)

Bottom Line: Menatetrenone is the brand name of a synthetic vitamin K2 that is chemically identical to menaquinone-4.Small RCTs showed that menatetrenone monotherapy decreased serum undercarboxylated osteocalcin (ucOC) concentrations, modestly increased lumbar spine BMD, and reduced the incidence of fractures (mainly vertebral fracture), and that combined alendronate and menatetrenone therapy enhanced the decrease in serum ucOC concentrations and further increased femoral neck BMD.This review of the literature revealed positive evidence for the effects of menatetrenone monotherapy on fracture incidence in postmenopausal women with osteoporosis.

View Article: PubMed Central - PubMed

Affiliation: Institute for Integrated Sports Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan. jiwamoto@a8.keio.jp.

ABSTRACT
Vitamin K may play an important role in the prevention of fractures in postmenopausal women with osteoporosis. Menatetrenone is the brand name of a synthetic vitamin K2 that is chemically identical to menaquinone-4. The present review study aimed to clarify the effect of menatetrenone on the skeleton in postmenopausal women with osteoporosis, by reviewing the results of randomized controlled trials (RCTs) in the literature. RCTs that investigated the effect of menatetrenone on bone mineral density (BMD), measured by dual-energy X-ray absorptiometry and fracture incidence in postmenopausal women with osteoporosis, were identified by a PubMed search for literature published in English. Eight studies met the criteria for RCTs. Small RCTs showed that menatetrenone monotherapy decreased serum undercarboxylated osteocalcin (ucOC) concentrations, modestly increased lumbar spine BMD, and reduced the incidence of fractures (mainly vertebral fracture), and that combined alendronate and menatetrenone therapy enhanced the decrease in serum ucOC concentrations and further increased femoral neck BMD. This review of the literature revealed positive evidence for the effects of menatetrenone monotherapy on fracture incidence in postmenopausal women with osteoporosis. Further studies are required to clarify the efficacy of menatetrenone in combination with bisphosphonates against fractures in postmenopausal women with osteoporosis.

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γ-Carboxylation of osteocalcin by vitamin K.
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nutrients-06-01971-f002: γ-Carboxylation of osteocalcin by vitamin K.

Mentions: Vitamin K is known to be a cofactor of γ-carboxylase, which converts three glutamic acid (Glu) residues in osteocalcin (OC) to γ-carboxyglutamic acid (Gla), and is thus essential for γ-carboxylation of OC [1,2,3,4]. Without this modification, OC becomes undercarboxylated OC (ucOC), which lacks structural integrity and the ability to bind to the mineral hydroxyapatite (Figure 2). The carboxylation reaction is completed as an intracellular posttranslational event, and secreted OC cannot longer be carboxylated. Impaired vitamin K nutritional status or warfarin use results in high concentrations of serum ucOC, resulting in an increased risk for fractures. In Japan, the cut-off values of serum ucOC concentrations for an increased risk for fractures associated are set at 4.5 ng/mL for treatment-naïve postmenopausal women and 2.6 ng/mL for postmenopausal women treated with amino-bisphosphonates [5,6]. Thus, vitamin K may play an important role in the prevention of fractures in postmenopausal women with osteoporosis.


Vitamin K₂ therapy for postmenopausal osteoporosis.

Iwamoto J - Nutrients (2014)

γ-Carboxylation of osteocalcin by vitamin K.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4042573&req=5

nutrients-06-01971-f002: γ-Carboxylation of osteocalcin by vitamin K.
Mentions: Vitamin K is known to be a cofactor of γ-carboxylase, which converts three glutamic acid (Glu) residues in osteocalcin (OC) to γ-carboxyglutamic acid (Gla), and is thus essential for γ-carboxylation of OC [1,2,3,4]. Without this modification, OC becomes undercarboxylated OC (ucOC), which lacks structural integrity and the ability to bind to the mineral hydroxyapatite (Figure 2). The carboxylation reaction is completed as an intracellular posttranslational event, and secreted OC cannot longer be carboxylated. Impaired vitamin K nutritional status or warfarin use results in high concentrations of serum ucOC, resulting in an increased risk for fractures. In Japan, the cut-off values of serum ucOC concentrations for an increased risk for fractures associated are set at 4.5 ng/mL for treatment-naïve postmenopausal women and 2.6 ng/mL for postmenopausal women treated with amino-bisphosphonates [5,6]. Thus, vitamin K may play an important role in the prevention of fractures in postmenopausal women with osteoporosis.

Bottom Line: Menatetrenone is the brand name of a synthetic vitamin K2 that is chemically identical to menaquinone-4.Small RCTs showed that menatetrenone monotherapy decreased serum undercarboxylated osteocalcin (ucOC) concentrations, modestly increased lumbar spine BMD, and reduced the incidence of fractures (mainly vertebral fracture), and that combined alendronate and menatetrenone therapy enhanced the decrease in serum ucOC concentrations and further increased femoral neck BMD.This review of the literature revealed positive evidence for the effects of menatetrenone monotherapy on fracture incidence in postmenopausal women with osteoporosis.

View Article: PubMed Central - PubMed

Affiliation: Institute for Integrated Sports Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan. jiwamoto@a8.keio.jp.

ABSTRACT
Vitamin K may play an important role in the prevention of fractures in postmenopausal women with osteoporosis. Menatetrenone is the brand name of a synthetic vitamin K2 that is chemically identical to menaquinone-4. The present review study aimed to clarify the effect of menatetrenone on the skeleton in postmenopausal women with osteoporosis, by reviewing the results of randomized controlled trials (RCTs) in the literature. RCTs that investigated the effect of menatetrenone on bone mineral density (BMD), measured by dual-energy X-ray absorptiometry and fracture incidence in postmenopausal women with osteoporosis, were identified by a PubMed search for literature published in English. Eight studies met the criteria for RCTs. Small RCTs showed that menatetrenone monotherapy decreased serum undercarboxylated osteocalcin (ucOC) concentrations, modestly increased lumbar spine BMD, and reduced the incidence of fractures (mainly vertebral fracture), and that combined alendronate and menatetrenone therapy enhanced the decrease in serum ucOC concentrations and further increased femoral neck BMD. This review of the literature revealed positive evidence for the effects of menatetrenone monotherapy on fracture incidence in postmenopausal women with osteoporosis. Further studies are required to clarify the efficacy of menatetrenone in combination with bisphosphonates against fractures in postmenopausal women with osteoporosis.

Show MeSH
Related in: MedlinePlus