**4. Clinical randomized controlled osteopenia/osteoporosis studies with menatetrenone‐4 (MK‐4) from 1 year duration, in countries with different background intake of vitamin K**

In 1998, Orimo et al from Japan evaluated the effects of menatetrenone‐4 (MK‐4) on bone and calcium metabolism in osteoporosis patients in a 24‐week double‐blind placebo‐controlled study, where 80 osteoporotic patients were included. Treatment was MK‐4, 90 mg/day (*n* = 39) or placebo (*n* = 41). Bone density was assessed on X‐ray films of the right, second metacarpal bone, using the microdensitometric method. In the MK‐4 group, bone density increased by about 2.2 ± 2.5% from the baseline; in the placebo group it decreased by about 7.3 ± 3.7% (*P* = 0.037, K2 treatment versus placebo). The excretion of γ‐carboxyglutamic acid (Gla) to the urine was markedly enhanced (i.e., from 72.6 ± 4.1 nmol/mg of creatinine before initiation of "medication," to 88.4 ± 5.4 during the 24th week subsequent to the sustained MK‐4 treatment (*P* = 0.008) period). In the group receiving placebo, no significant changes in the excretion of urinary Gla could be observed. However, during the 24‐week long treatment period, the urinary ratio of calcium over creatinine in the K2 treatment group was reduced from 0.14 ± 0.02 to 0.12 ± 0.02, respectively. However, in the placebo group it increased from 0.15 ± 0.02 to 0.19 ± 0.03. Accordingly, the 24‐week levels shown by members of both the MK‐4 and the placebo groups turned out to be significantly different (*P* = 0.03) with unpaired test. Finally, it should be noted that there were but a few adverse effects, being attributable to the vitamin MK‐4 treatment. One patients increased hepatic enzymes of GOT, GPT, al‐P, and γ‐GTP evaluated as probable relationship. The results suggest that MK‐4, at a dosage of 90 mg/day, is effective in maintaining peripheral cortical bone density and is safe in treatment of osteoporosis. The dose was increased in order to maintaining peripheral cortical density. Interference of diet was not observed. This study is one of very few, where side effects of the treatment were observed [39].

increased lumbar BMD by 1.5 %, *p* < 0.001. These findings indicate that combined administra‐ tion of vitamin D3 and MK‐4, compared with calcium administration alone, appears to be instrumental in increasing the BMD‐values of the lumbar spine in postmenopausal women

Vitamin K2 and Bone Health http://dx.doi.org/10.5772/64876 109

Ushiroyama et al. completing a randomized 2‐year study in 2002, investigated the therapeutic effect of the combined use of menatetrenone MK‐4 and vitamin D3 on vertebral bone mineral density in 172 postmenopausal women with low bone mass and osteoporosis. Four groups, each with 43 subjects received the following; either (a) MK‐4, 45 mg/day, (b) standard vitamin D3 supplement, (c) combined MK‐4 and vitamin D3 therapy, and (d) control group receiving dietary therapy alone. BMD (bone mineral density) was assessed before initiation of therapy and subsequent to 6–24 months of treatment, respectively. Analyzed biological markers of osseous metabolism constituted: serum type 1 collagen carboxyterminal propeptide (P1CP), intact or total osteocalcin, as well as urinary pyridinoline. Tests for potential of blood coagu‐ lation was done analyzing "activated‐partial‐thromboplastin‐time" (APTT), as well as assessment of levels of antithrombin III (AT III), fibrinogen, and plasminogen, respectively. Conclusions summarized in the paper were combined therapy with MK‐4 and vitamin D3 given for 24 months significantly increased bone mineral density = BMD (4.92 ± 7.89%), *P* < 0.001, but also while MK‐4 alone was significantly enhanced by 0.135 ± 5.44%, *P* < 0.05. A majority of the population (77.5%) increased their BMD values, while 22.5% experienced the opposite. In the MK‐4 group, the marker of bone formation (P1CP) showed an increase by 20% after 6 months, and while thereafter returning to baseline. Urinary pyridinoline was signifi‐ cantly increased after 6 month, and peaked after 18 months (89.6 ± 112.3%), while slightly decreasing at 24 months to 53.4 ± 55.7%, *P* < 0.05. In the combined MK‐4 and D3 group, P1PC was unchanged for the first 12 months, then it increased at 24 months to 24.2 ± 23.1%, *P* < 0.05. Urinary pyridinoline was increased throughout the 24 months to 84.5 ± 51.9%, *P* < 0.01. The MK‐4 group at 24 months showed a significant positive correlation between changes of P1CP and changes of BMD, *P* < 0.001. In the MK‐4 and D3 groups at 12 months, a significant positive correlation (*P* < 0.03) between changes of P1PC and changes of BMD could be seen. In the MK‐ 4 and D3 groups, at 12 and 24 months, respectively, significant negative correlations between changes in pyridinoline and changes in BMD (*P* < 0.001 and *P* < 0.004, respectively) could be observed. The authors conclude that these findings indicate both concomitant enhancement of net bone formation, as well as some osseous resorption activities. Additionally, observed significant increments in the coagulation and fibrinolytic reaction pathways were seen. However, they were both restricted within normal physiological range, suggesting mainte‐ nance of a normalized balance within the fibrinolysis versus coagulation system, since no side

In 2007, Knapen et al. from the Netherlands presented the result of a 3‐year randomized clinical intervention study of 325 healthy postmenopausal non‐ osteoporotic women receiving MK‐4, 45 mg/day, or placebo. BMC and hip geometry were assessed by DXA, and bone strength indices were calculated from DXA‐BMD, femoral neck width (FNW) and hip axis length (HAL). Computations showed that MK‐4 significantly improved the hip bone strength, BMC and FNW, but in the placebo group, bone strength decreased significantly. However, MK‐4 did

with osteoporosis [41, 42].

effects were observed [43].

In 2000, Shiraki et al. conducted a 2‐year study in Japan, to assess whether MK‐4 effectively prevented the incidence of new fractures in osteoporotic patients. Two hundred forty‐one osteoporotic women were enrolled in a 24‐month, randomized, and open label study. The population constituted: a control group without treatment (*n* = 121) and an MK‐4 group (*n* = 120), the latter receiving 45 mg/day. All patients received follow up measurements of lumbar bone mineral density (LBMD) analyzed by DXA and the occurrence of new clinical fractures had occurred. Both serum concentrations of Glu‐osteocalcin (Glu‐OC) (RIA, Takara Japan), as well as MK‐4 were analyzed after termination of the follow‐up period, while both the level of serum‐OC (RIA, CIS, France) and excretion of deoxypyridinoline (DPD) to the urine were analyzed prior to and at the end of the treatment. The demographic data of the present groups did not differ significantly, and the results obtained run as follows: the clinical vertebral fracture incidence in the control group was 30, compared with 13 in the MK‐4 treated group (*P* = 0.027). Furthermore, the percentage change from the initial LBMD value at 6–24 months after the initiation of the study ranged between −1.8 ± 0.6, and −3.3 ± 0.8% for the control group, and between 1.4 ± 0.7, and −0.5 ± 1.0% for the MK‐4‐treated group, respectively. The alterations in LBMD‐values around each measure point turned out to be significantly different, when comparing the control group with the treated group (*P* = 0.0010 at 6 months, *P* = 0.0153 after a year, and *P* = 0.0339 after 2 years, respectively). The blood concentrations of Glu‐OC at termination of the period of observation of the controls and the group receiving active "drug" were 3.0 ± 0.30 and 1.6 ± 0.10 ng/ml, respectively (*P* < 0.0001), while blood concentrations of OC (as analyzed by standard radioimmunoassay (RIA) methodology, gave a marked and significant rise (42.4 ± 6.9%) over basal value observed in the treated group at 24 months, but only 18.2 ± 6.1% for the individuals constituting the controls (*P* = 0.0081)). However, one did not find any significant change in the amount of DPD excreted into the urine of the treatment group members. This compilation of information indicates that MK‐4 treatment is effective in reducing the incidence of additional fractures, even though the MK‐4 treated individuals failed to show an enhancement of LBMD. Lastly, the study was able to show that MK‐4 treatment elevates the levels of γ‐carboxylated OC [40].

In 2000, Iwamoto et al. showed in 92 postmenopausal women, aged 55–81 years, completing a 2‐year randomized controlled trial in four groups receiving either menatetrenone (MK‐4, 45 mg/day), 1α‐hydroxyvitamin D3 (0.75 μg/day), a combination of MK‐4 and D3 (same dosage as above), or calcium lactate (2 g/day). The MK‐4 and vitamin D3 groups experienced significant enhancements of their BMD‐values (+0.91 and 0.38%), compared to the "Calcium group" (–0.79%), while the combined MK‐4 and D treatment, being synergistic, significantly increased lumbar BMD by 1.5 %, *p* < 0.001. These findings indicate that combined administra‐ tion of vitamin D3 and MK‐4, compared with calcium administration alone, appears to be instrumental in increasing the BMD‐values of the lumbar spine in postmenopausal women with osteoporosis [41, 42].

groups turned out to be significantly different (*P* = 0.03) with unpaired test. Finally, it should be noted that there were but a few adverse effects, being attributable to the vitamin MK‐4 treatment. One patients increased hepatic enzymes of GOT, GPT, al‐P, and γ‐GTP evaluated as probable relationship. The results suggest that MK‐4, at a dosage of 90 mg/day, is effective in maintaining peripheral cortical bone density and is safe in treatment of osteoporosis. The dose was increased in order to maintaining peripheral cortical density. Interference of diet was not observed. This study is one of very few, where side effects of the treatment were observed

In 2000, Shiraki et al. conducted a 2‐year study in Japan, to assess whether MK‐4 effectively prevented the incidence of new fractures in osteoporotic patients. Two hundred forty‐one osteoporotic women were enrolled in a 24‐month, randomized, and open label study. The population constituted: a control group without treatment (*n* = 121) and an MK‐4 group (*n* = 120), the latter receiving 45 mg/day. All patients received follow up measurements of lumbar bone mineral density (LBMD) analyzed by DXA and the occurrence of new clinical fractures had occurred. Both serum concentrations of Glu‐osteocalcin (Glu‐OC) (RIA, Takara Japan), as well as MK‐4 were analyzed after termination of the follow‐up period, while both the level of serum‐OC (RIA, CIS, France) and excretion of deoxypyridinoline (DPD) to the urine were analyzed prior to and at the end of the treatment. The demographic data of the present groups did not differ significantly, and the results obtained run as follows: the clinical vertebral fracture incidence in the control group was 30, compared with 13 in the MK‐4 treated group (*P* = 0.027). Furthermore, the percentage change from the initial LBMD value at 6–24 months after the initiation of the study ranged between −1.8 ± 0.6, and −3.3 ± 0.8% for the control group, and between 1.4 ± 0.7, and −0.5 ± 1.0% for the MK‐4‐treated group, respectively. The alterations in LBMD‐values around each measure point turned out to be significantly different, when comparing the control group with the treated group (*P* = 0.0010 at 6 months, *P* = 0.0153 after a year, and *P* = 0.0339 after 2 years, respectively). The blood concentrations of Glu‐OC at termination of the period of observation of the controls and the group receiving active "drug" were 3.0 ± 0.30 and 1.6 ± 0.10 ng/ml, respectively (*P* < 0.0001), while blood concentrations of OC (as analyzed by standard radioimmunoassay (RIA) methodology, gave a marked and significant rise (42.4 ± 6.9%) over basal value observed in the treated group at 24 months, but only 18.2 ± 6.1% for the individuals constituting the controls (*P* = 0.0081)). However, one did not find any significant change in the amount of DPD excreted into the urine of the treatment group members. This compilation of information indicates that MK‐4 treatment is effective in reducing the incidence of additional fractures, even though the MK‐4 treated individuals failed to show an enhancement of LBMD. Lastly, the study was able to show that MK‐4 treatment

In 2000, Iwamoto et al. showed in 92 postmenopausal women, aged 55–81 years, completing a 2‐year randomized controlled trial in four groups receiving either menatetrenone (MK‐4, 45 mg/day), 1α‐hydroxyvitamin D3 (0.75 μg/day), a combination of MK‐4 and D3 (same dosage as above), or calcium lactate (2 g/day). The MK‐4 and vitamin D3 groups experienced significant enhancements of their BMD‐values (+0.91 and 0.38%), compared to the "Calcium group" (–0.79%), while the combined MK‐4 and D treatment, being synergistic, significantly

[39].

108 Vitamin K2 - Vital for Health and Wellbeing

elevates the levels of γ‐carboxylated OC [40].

Ushiroyama et al. completing a randomized 2‐year study in 2002, investigated the therapeutic effect of the combined use of menatetrenone MK‐4 and vitamin D3 on vertebral bone mineral density in 172 postmenopausal women with low bone mass and osteoporosis. Four groups, each with 43 subjects received the following; either (a) MK‐4, 45 mg/day, (b) standard vitamin D3 supplement, (c) combined MK‐4 and vitamin D3 therapy, and (d) control group receiving dietary therapy alone. BMD (bone mineral density) was assessed before initiation of therapy and subsequent to 6–24 months of treatment, respectively. Analyzed biological markers of osseous metabolism constituted: serum type 1 collagen carboxyterminal propeptide (P1CP), intact or total osteocalcin, as well as urinary pyridinoline. Tests for potential of blood coagu‐ lation was done analyzing "activated‐partial‐thromboplastin‐time" (APTT), as well as assessment of levels of antithrombin III (AT III), fibrinogen, and plasminogen, respectively. Conclusions summarized in the paper were combined therapy with MK‐4 and vitamin D3 given for 24 months significantly increased bone mineral density = BMD (4.92 ± 7.89%), *P* < 0.001, but also while MK‐4 alone was significantly enhanced by 0.135 ± 5.44%, *P* < 0.05. A majority of the population (77.5%) increased their BMD values, while 22.5% experienced the opposite. In the MK‐4 group, the marker of bone formation (P1CP) showed an increase by 20% after 6 months, and while thereafter returning to baseline. Urinary pyridinoline was signifi‐ cantly increased after 6 month, and peaked after 18 months (89.6 ± 112.3%), while slightly decreasing at 24 months to 53.4 ± 55.7%, *P* < 0.05. In the combined MK‐4 and D3 group, P1PC was unchanged for the first 12 months, then it increased at 24 months to 24.2 ± 23.1%, *P* < 0.05. Urinary pyridinoline was increased throughout the 24 months to 84.5 ± 51.9%, *P* < 0.01. The MK‐4 group at 24 months showed a significant positive correlation between changes of P1CP and changes of BMD, *P* < 0.001. In the MK‐4 and D3 groups at 12 months, a significant positive correlation (*P* < 0.03) between changes of P1PC and changes of BMD could be seen. In the MK‐ 4 and D3 groups, at 12 and 24 months, respectively, significant negative correlations between changes in pyridinoline and changes in BMD (*P* < 0.001 and *P* < 0.004, respectively) could be observed. The authors conclude that these findings indicate both concomitant enhancement of net bone formation, as well as some osseous resorption activities. Additionally, observed significant increments in the coagulation and fibrinolytic reaction pathways were seen. However, they were both restricted within normal physiological range, suggesting mainte‐ nance of a normalized balance within the fibrinolysis versus coagulation system, since no side effects were observed [43].

In 2007, Knapen et al. from the Netherlands presented the result of a 3‐year randomized clinical intervention study of 325 healthy postmenopausal non‐ osteoporotic women receiving MK‐4, 45 mg/day, or placebo. BMC and hip geometry were assessed by DXA, and bone strength indices were calculated from DXA‐BMD, femoral neck width (FNW) and hip axis length (HAL). Computations showed that MK‐4 significantly improved the hip bone strength, BMC and FNW, but in the placebo group, bone strength decreased significantly. However, MK‐4 did not affect the DXA‐BMD values. It was therefore speculated that the high vitamin K2 intake prevented the postmenopausal, nonosteoporotic bone loss. The importance of K vitamins for optimal bone health has been suggested on the basis of population‐based analyses, however, intervention trials performed with DXA‐BMD serving as measures of clinical endpoints have given contradicting conclusions. In contrast, BMC, compared with DXA‐BMD does not take into account the geometry (size, thickness) of bone, which is construed as an independent contributor to and "interpreter" of bone resilience and fracture risk [44].

(nine vertebral and four lumbar), in the MK‐4 group total 10 (seven vertebral and three lumbar), and in the C‐group; total 12 (seven thoracal and five lumbar). No significant differences could be spotted between groups. It was therefore concluded that a maintained BMD seen in the MK‐ 4 group could be construed as a positive effect, which should be evaluated together with

Vitamin K2 and Bone Health http://dx.doi.org/10.5772/64876 111

In 2003, Iwamoto et al. examined 98 postmenopausal osteoporotic women in a randomized, controlled, 2 years study, comprising four groups: (1) MK‐4, 45 mg/day of vitamin K; (2) etidronate 200 mg/day for 14 days per 3 months; (3) etidronate and MK‐4 combined; and (4) calcium supplement. End points assessments were: Forearm (distal radius) BMD measured by DXA using DTX‐200 (Osteometer®), and incidence of vertebral fractures (level T4‐L4). Results reported are summarized as follows: the forearm BMD in the calcium group was reduced from baseline, sustained by MK‐4, increased significantly by etidronate, and increased even more in the MK‐4 and etidronate group. The incidence of vertebral fractures in the MK‐4 group was 8.0%, in the etidronate group 8.7%, in the MK‐4 and etidronate group 3.8%, and in the calcium group 20.8%, respectively. The compelling conclusion is combined treatment with MK‐4 and bisphosphonates showed significant different (*P* < 0.01) between other groups alone. The author concluded that combined treatment seems to have the greatest efficacy in prevention of new osteoporotic fractures, and this treatment should be recommended to treat osteoporotic

Ishida and Kawai published in 2004 a 2‐year long study, examining 396 postmenopausal women with osteoporosis, randomized to six equally sized groups: (1) hormone replacement therapy (conjugated estrogen 0.625 mg/day plus medroxyprogesterone 2.5 mg/day), (2) etidronate (2 weeks of treatment with 200 mg/day followed by a 10‐week medication‐free period), (3) ell calcitonin (20 IU/week), (4) α‐calcidol 1 μg/day, (5) MK‐4 45 mg/day, and (6) control group (i.e., no treatment). End point BMD, bone markers and incidence of vertebral fractures served as clinically relevant end point measures. The results (2‐year mean changes in BMD) were 2% for the hormone replacement therapy, −0.5% for the etidronate treatment, 1.6% for the calcitonin treatment, −3.6% for the α‐calcidol treatment, −1.9 for the MK‐4 treatment, and −3.3 for the controls, respectively. Seventeen (26%) of the 66 control patients developed new vertebral fractures. Compared with controls, the relative risk of incurring vertebral fractures was 0.35 (95% CI: 0.14–0.83) in the hormone replacement therapy, 0.40 (95% CI: 0.17–0.92) in the etidronate group, 0.41 (95% CI: 0.17–0.93) in the calcitonin group, 0.56 (95% CI: 0.26–1.12) in the α‐calcidol group, and 0.44 (95% CI: 0.20–0.99) in the MK‐4 group, respec‐ tively. Hence, the conclusion: a substantial and significant reduction in the incidence of vertebral fractures was achieved due to either: (a) hormone replacement therapy, (b) etidronate, or (c) calcitonin medication. Significant improvements in BMD were obtained by the patients

enrolled in the hormone replacement therapy group and in the calcitonin group [49].

Hirao et al. conducted a 1‐year study in Japan in 2008. He enrolled and examined 48 postme‐ nopausal women, but only 44 were followed up after 1 year. This randomized controlled study consisted of the following groups A, monotherapy of alendronate (5 mg/day) and group AK, alendronate plus MK‐4 (5 mg/day an 45 mg/day, respectively). The take home message was clear: MK‐4 decreased undercarboxylated osteocalcin significantly more than alendronate,

etidronate treatment [46].

women [47, 48].

Jiang et al. conducted a 1‐year study in China in 2014. In this randomized, double‐blinded study, it was evaluated whether the efficacy of MK‐4 is inferior to α‐calcidol in Chinese postmenopausal women. Two hundred and thirty‐six women were randomized to two groups: Group MK‐4, receiving 45 mg/day or Group α‐calcidol, receiving 0.5 μg/day, respectively. Furthermore, all enrolled individuals ingested 500 mg/day of calcium. Assessment of bone mineral density (BMD) post‐treatment, onset or occurrence of new fractures, as well as serum OC and ucOC levels were matched with patient baseline values in both patient groups. The information obtained was as follows: 90.3% of the patients completed the investigation. Results showed that the BMD‐values in the MK‐4 group significantly increased from baseline by 1.2% at the lumbar spine, and 2.7% at the trochanter, respectively (*P* = 0.001). The percentage enhancement in BMD in the α‐calcidol group and the MK‐4 group was 2.2 and 1.8%, respec‐ tively (*P* = 0.001). No difference could be seen when comparing either treatment groups. And one could not spot any alterations in femoral neck BMD between the populations observed. However, one tibia and one femoral neck fracture in the MK‐4 group, and three lumbar spine compressive and one forearm fracture in the α‐calcidol group revealed the appearance of new fractures (*P* < 0.05). Within the MK‐4 group, the concentration of OC and ucOC, respectively, fell from baseline levels by some 39 and 82%, respectively (*P* < 0.001). In the α‐calcidol group, OC and ucOC fell by some 26 and 35%, respectively (*P* < 0.001), and the decreases in serum OC and ucOC were more obvious in the MK‐4 group than in the calcidol group (*P* < 0.001). The safety profile of menatetrenone was similar to that of α‐calcidol. It was therefore concluded that MK‐4 is an effective and safe choice in the treatment of postmenopausal osteoporosis in Chinese women [45].

Bisphosphonates, combined with vitamin D and calcium are widely used around the world in the treatment of osteoporotic patients. Vitamin K apparently sustains the lumbar BMD, thus reducing the incidence of osteoporotic fractures it was natural to investigate and compare bisphosphonates and MK‐4.

In 2001, Iwamoto et al. presented a 2‐year preliminary randomized study, comparing the effects of etidronate (E) and MK‐4 on forearm BMD‐values and fracture incidence. Seventy‐two osteoporotic women, all 5 years after menopause were enrolled. The E‐group received 200 mg/ day, 14 days per 3 months; *n* = 25, the MK‐4 group received 45 mg/day; *n* = 23, and the placebo (C = control group) was given calcium lactate 2 g/day; *n* = 24. At baseline, there was no difference between the three groups. Significant results obtained were summarized as follows: mean percentage change in BMD in the E‐group was a significant increase of 2.1%; *P* < 0.01. In the MK‐4 group, it was −0.1%, which was not significant. In the C‐group, there was a significant decrease in BMD; −1.7%; *P* < 0.0001. Incidence of new fractures was in the E‐group; total 13 (nine vertebral and four lumbar), in the MK‐4 group total 10 (seven vertebral and three lumbar), and in the C‐group; total 12 (seven thoracal and five lumbar). No significant differences could be spotted between groups. It was therefore concluded that a maintained BMD seen in the MK‐ 4 group could be construed as a positive effect, which should be evaluated together with etidronate treatment [46].

not affect the DXA‐BMD values. It was therefore speculated that the high vitamin K2 intake prevented the postmenopausal, nonosteoporotic bone loss. The importance of K vitamins for optimal bone health has been suggested on the basis of population‐based analyses, however, intervention trials performed with DXA‐BMD serving as measures of clinical endpoints have given contradicting conclusions. In contrast, BMC, compared with DXA‐BMD does not take into account the geometry (size, thickness) of bone, which is construed as an independent

Jiang et al. conducted a 1‐year study in China in 2014. In this randomized, double‐blinded study, it was evaluated whether the efficacy of MK‐4 is inferior to α‐calcidol in Chinese postmenopausal women. Two hundred and thirty‐six women were randomized to two groups: Group MK‐4, receiving 45 mg/day or Group α‐calcidol, receiving 0.5 μg/day, respectively. Furthermore, all enrolled individuals ingested 500 mg/day of calcium. Assessment of bone mineral density (BMD) post‐treatment, onset or occurrence of new fractures, as well as serum OC and ucOC levels were matched with patient baseline values in both patient groups. The information obtained was as follows: 90.3% of the patients completed the investigation. Results showed that the BMD‐values in the MK‐4 group significantly increased from baseline by 1.2% at the lumbar spine, and 2.7% at the trochanter, respectively (*P* = 0.001). The percentage enhancement in BMD in the α‐calcidol group and the MK‐4 group was 2.2 and 1.8%, respec‐ tively (*P* = 0.001). No difference could be seen when comparing either treatment groups. And one could not spot any alterations in femoral neck BMD between the populations observed. However, one tibia and one femoral neck fracture in the MK‐4 group, and three lumbar spine compressive and one forearm fracture in the α‐calcidol group revealed the appearance of new fractures (*P* < 0.05). Within the MK‐4 group, the concentration of OC and ucOC, respectively, fell from baseline levels by some 39 and 82%, respectively (*P* < 0.001). In the α‐calcidol group, OC and ucOC fell by some 26 and 35%, respectively (*P* < 0.001), and the decreases in serum OC and ucOC were more obvious in the MK‐4 group than in the calcidol group (*P* < 0.001). The safety profile of menatetrenone was similar to that of α‐calcidol. It was therefore concluded that MK‐4 is an effective and safe choice in the treatment of postmenopausal osteoporosis in

Bisphosphonates, combined with vitamin D and calcium are widely used around the world in the treatment of osteoporotic patients. Vitamin K apparently sustains the lumbar BMD, thus reducing the incidence of osteoporotic fractures it was natural to investigate and compare

In 2001, Iwamoto et al. presented a 2‐year preliminary randomized study, comparing the effects of etidronate (E) and MK‐4 on forearm BMD‐values and fracture incidence. Seventy‐two osteoporotic women, all 5 years after menopause were enrolled. The E‐group received 200 mg/ day, 14 days per 3 months; *n* = 25, the MK‐4 group received 45 mg/day; *n* = 23, and the placebo (C = control group) was given calcium lactate 2 g/day; *n* = 24. At baseline, there was no difference between the three groups. Significant results obtained were summarized as follows: mean percentage change in BMD in the E‐group was a significant increase of 2.1%; *P* < 0.01. In the MK‐4 group, it was −0.1%, which was not significant. In the C‐group, there was a significant decrease in BMD; −1.7%; *P* < 0.0001. Incidence of new fractures was in the E‐group; total 13

contributor to and "interpreter" of bone resilience and fracture risk [44].

Chinese women [45].

bisphosphonates and MK‐4.

110 Vitamin K2 - Vital for Health and Wellbeing

In 2003, Iwamoto et al. examined 98 postmenopausal osteoporotic women in a randomized, controlled, 2 years study, comprising four groups: (1) MK‐4, 45 mg/day of vitamin K; (2) etidronate 200 mg/day for 14 days per 3 months; (3) etidronate and MK‐4 combined; and (4) calcium supplement. End points assessments were: Forearm (distal radius) BMD measured by DXA using DTX‐200 (Osteometer®), and incidence of vertebral fractures (level T4‐L4). Results reported are summarized as follows: the forearm BMD in the calcium group was reduced from baseline, sustained by MK‐4, increased significantly by etidronate, and increased even more in the MK‐4 and etidronate group. The incidence of vertebral fractures in the MK‐4 group was 8.0%, in the etidronate group 8.7%, in the MK‐4 and etidronate group 3.8%, and in the calcium group 20.8%, respectively. The compelling conclusion is combined treatment with MK‐4 and bisphosphonates showed significant different (*P* < 0.01) between other groups alone. The author concluded that combined treatment seems to have the greatest efficacy in prevention of new osteoporotic fractures, and this treatment should be recommended to treat osteoporotic women [47, 48].

Ishida and Kawai published in 2004 a 2‐year long study, examining 396 postmenopausal women with osteoporosis, randomized to six equally sized groups: (1) hormone replacement therapy (conjugated estrogen 0.625 mg/day plus medroxyprogesterone 2.5 mg/day), (2) etidronate (2 weeks of treatment with 200 mg/day followed by a 10‐week medication‐free period), (3) ell calcitonin (20 IU/week), (4) α‐calcidol 1 μg/day, (5) MK‐4 45 mg/day, and (6) control group (i.e., no treatment). End point BMD, bone markers and incidence of vertebral fractures served as clinically relevant end point measures. The results (2‐year mean changes in BMD) were 2% for the hormone replacement therapy, −0.5% for the etidronate treatment, 1.6% for the calcitonin treatment, −3.6% for the α‐calcidol treatment, −1.9 for the MK‐4 treatment, and −3.3 for the controls, respectively. Seventeen (26%) of the 66 control patients developed new vertebral fractures. Compared with controls, the relative risk of incurring vertebral fractures was 0.35 (95% CI: 0.14–0.83) in the hormone replacement therapy, 0.40 (95% CI: 0.17–0.92) in the etidronate group, 0.41 (95% CI: 0.17–0.93) in the calcitonin group, 0.56 (95% CI: 0.26–1.12) in the α‐calcidol group, and 0.44 (95% CI: 0.20–0.99) in the MK‐4 group, respec‐ tively. Hence, the conclusion: a substantial and significant reduction in the incidence of vertebral fractures was achieved due to either: (a) hormone replacement therapy, (b) etidronate, or (c) calcitonin medication. Significant improvements in BMD were obtained by the patients enrolled in the hormone replacement therapy group and in the calcitonin group [49].

Hirao et al. conducted a 1‐year study in Japan in 2008. He enrolled and examined 48 postme‐ nopausal women, but only 44 were followed up after 1 year. This randomized controlled study consisted of the following groups A, monotherapy of alendronate (5 mg/day) and group AK, alendronate plus MK‐4 (5 mg/day an 45 mg/day, respectively). The take home message was clear: MK‐4 decreased undercarboxylated osteocalcin significantly more than alendronate, which is known not to influence the degree of carboxylated osteocalcin. In the AK group, the femoral neck BMD was significantly increased. The small number of patients enrolled, and the short observation time undermines any conclusion drawn from this study. Further investiga‐ tions using this combination therapy were recommended [50].

any other measurements sites. This was most probably due to the shorter follow‐up time, i.e.,

After solid organ transplantations, loss of bone mass often occurs and may cause substantial health problems. In a study (published in 2010) on such a patients group, Forli et al. from Norway looked at the effect of MK‐7 on bone mass, measured as BMD of the lumbar spine. Despite the fact that the impact of MK‐7 on the measured BMD was not conclusive, it was recommended that further studies over an extended period of time should be conducted. Here,

This study was the first in organ transplantation, featuring the effect of MK‐7 on bone mass, 1 year after lung and heart transplantation. Postoperatively, 35 lung and 59 heart recipients were actively treated with MK‐7 in a prospective and longitudinal study, receiving MK‐7 supple‐ ment, 180 μg/day or placebo. The results reported were the following: 1 year after solid organ transplantation, the difference between MK‐7 and placebo for the lumbar spine (L2–L4) BMD

*P* = 0.5. Scrutinizing the lung recipients separately, the difference for BMC was 3.39 g (SE = 1.65), *P* = 0.048. In the heart recipients, however, observed values were 0.45 (SE = 0.02) g, *P* =

In a stepwise linear regression analysis, alterations in the L2‐L4 BMD, controlled for alleged confounding variables (which include the use of bisphosphonates), significant predictors

frequent, and that PTH (parathyroid hormone) levels were augmented in the MK‐7 group, indicating a more imminent need for ingestion of vitamin D. In conclusion, it turned out that 12 months of MK‐7 ingestion generally suggests a positive effect on BMD of the lumbar spine, but with diverging responses in "cardio‐pulmonary" recipients. Thus, the patients' vitamin D status would benefit from a closer monitoring during vitamin K supplementation [56].

Knapen et al., the Netherlands, published in 2013 the results of their 3 year study on the effect of low‐dose MK‐7 supplementation on bone loss in 244 healthy postmenopausal women. The study was a double‐blind, randomized placebo controlled study, with two groups: (a) active low‐dose vitamin K2 (MK‐7, 180 μg/day), and placebo. Their main task was to investigate

Secondary to an improved and favorable vitamin K status, MK‐7 ingestion from supplements should have the possibility to significantly reduced age‐related loss of bone mineral density and ensuing bone mechanical properties. Hence, low‐dose MK‐7 supplements should conse‐ quently result in preventing bone loss in postmenopausal women. In spite of contradictory data emanating from trials with vitamin K supplementation on the status of bone health, the European Food Safety Authorities (EFSA) has accepted the health claim on vitamin K's role in the maintenance of normal and healthy bone structure. In accordance with EFSA's opinion, it was clearly demonstrated that a 3‐year high‐dose of vitamin K1 and MK‐4 supplementation

whether low‐dose MK‐7 supplements beneficially could affect bone health in general.

, *P* = 0.055, and for L2 to L4, BMC emerged as 1.33 (SE = 1.91) g/cm2

, *P* = 0.019). It so happened, that insufficient vitamin D status was

,

113

, *P* = 0.001) and (b) MK‐7 versus

Vitamin K2 and Bone Health http://dx.doi.org/10.5772/64876

after only 1 year of MK‐7 exposure [55].

we refer to the main findings in the study.

0.9 subsequent to correcting for measures of baseline values.

turned out to be: (a) organ (if heart = 1, BMD = −0.065 g/cm2

was 0.028 (SE 0.014) g/cm2

placebo (BMD = 0.034 g/cm2

improved bone health after menopause.

Je et al. from Korea published in 2011, a study evaluating the effects of MK‐4 supplementation on bone mineral density and undercarboxylated osteocalcin (ucOC) in 78 postmenopausal Korean women 60‐years‐old plus. These women, not receiving any medical treatment, were randomized into two groups: (1) calcium and vitamin D, *n* = 40) or (2) vitamin K supplemen‐ tation, *n* = 38, receiving 15 mg of MK‐4 three times a day after every meal, calcium carbonate 315 mg twice daily, and active vitamin D3, 400 UI once a day. The dosage of calcium and vitamin D3 was the same in both groups. After 6 months of treatment, the members of the MK‐4 group showed a decrease in ucOC (−1.6 ± 1.6 ng/dl versus −0.4 ± 1.1 ng/dl) with a *P*‐value of 0.008. The vitamin K (MK‐4) group members showed a significant improvement of L3 BMD‐values, however, no significant enhancement of the BMD‐values in L1, L2, and L4. Similarly, no significant increase was observed for femoral BMD, which remained unchanged in the women receiving vitamin D and calcium [51].

In 2012, Fang et al. presented a meta‐analysis of randomized controlled trials published during the period of 1999−2009. The analysis examined the role of vitamin K on bone mineral density (BMD). The study revealed that vitamin MK‐4 supplementation was associated with increased BMD at the lumbar spine, however not necessarily at the femoral neck. This untoward heterogeneity may be the result, may reside within different participant groups, different regions of the skeleton, gender, and type of vitamin K1 and MK‐4 supplementation. Hence, further studies are deemed required to investigate and unravel the detailed effects of vitamin K2 sub"populations" or metabolites on BMD [52].
