Effects of long-term vitamin K(1) (phylloquinone) or vitamin K(2) (menaquinone-4) supplementation on body composition and serum parameters in rats.

Vitamin K is a cofactor for γ-glutamyl carboxylase, which is an essential enzyme for the γ-carboxylation of vitamin K-dependent proteins such as osteocalcin and matrix Gla protein. Although it has been suggested that vitamin K plays an important role in the improvement of bone metabolism, the relationship between dietary vitamin K intake and bone metabolism has not been thoroughly investigated. Moreover, vitamin K is thought to have other actions beyond influencing the γ-carboxylation status. In the present study, we examined the effects of the long-term addition of phylloquinone (PK) or menaquinone-4 (MK-4) to a control diet on bone mineral density, bone strength, body composition, and serum parameters in rats. A total of 23 female Sprague-Dawley strain rats (6 weeks old) were divided into three groups: basic control diet group, PK diet (PK: 600mg/kg diet) group, and MK diet (MK-4: 600mg/kg diet) group. Three months after starting the experimental diet, the addition of PK to the basic control diet significantly increased the bone mineral density (BMD) of the femur (p<0.05). In the MK group, there was no significant difference in the BMD of the femur. However, two types of bone strength parameter: the minimum cross-sectional moment of inertia and the polar moment of inertia, were significantly higher in the MK group than in the control (p<0.05, respectively). Furthermore, the femoral bone parameters (the width, dry weight and ash weight, and cortical, cancellous, trabecular, and total bone mineral contents) in the MK group were increased significantly compared with the control. Interestingly, the addition of PK or MK-4 significantly decreased the total fat accumulation (p<0.01 and p<0.05, respectively), and serum triglycerides were reduced by 48% in the PK group and 29% in the MK group compared with the control. There were no significant differences in the levels of serum calcium, phosphorus, alkaline phosphatase, growth hormone, insulin-like growth hormone-1, insulin-like growth hormone binding protein-3, and cross-linked N-teleopeptide of type I collagen among the three groups. This is the first study to demonstrate the effect of the long-term addition of PK or MK-4 to the control diet on body composition and serum parameters in an in vivo system using rats. Further studies on the mechanism of vitamin K supplementation in the regulation of bone metabolism would provide valuable data on the prevention of lifestyle-related disorders, including osteoporosis.

[Development of oral function and eating habits of infants living in a city area of Japan: in relation to the results of dental health examinations of infants aged 14 months at public health centers].

OBJECTIVE: The aim of this study was to investigate the relationships between eruption of deciduous teeth and eating habits determined by health examinations of infants. METHODS: We verified eruption of deciduous teeth based on observations of 455 fourteen-month-old infants at health examinations in a ward of Tokyo, and performed a questionnaire survey involving their mothers regarding the hardness of infants' meals and their eating habits. We examined 420 infants excluding 17 whose births were 'pre-term delivery (born at or before 36 weeks)' and 18 whose questionnaire had excessive omissions. RESULTS: The percentage of infants who began a weaning diet at 5 to 6 months of age was 81.4%, and 71.2% of mothers considered their infant's age in months before starting a weaning diet. We divided the children into three stages: those not showing full eruption of the eight front deciduous teeth (stage I, 27.4%); those with full eruptions of the eight front deciduous teeth excluding the first primary molars (stage II, 61.9%); those with full eruptions of the first primary molars (stage III, 10.7%). Most mothers cooked meals considering the hardness of the gingival gums (stage I; 53.5%, stage II; 54.4%, stage III; 40.0%). The percentage of mothers who cooked meals considering the hardness of the primary molars was 14.0 and 15.1% in stages I and II, respectively. In addition, the percentage who cooked meals while considering the hardness in relation to adult meals was 7.0, 9.7, and 24.4% in stages I, II, and III, respectively. Moreover, the percentage considering the salt-taste in relation to adult meals was 13.2, 17.3, and 22.2% in stages I, II, and III, respectively. CONCLUSION: In the present study, we obtained valuable data showing that the timing deciduous teeth eruption varies among individuals. These results suggested that nutritional education on the appropriate quality of meals for infants based on their state of deciduous teeth eruption is necessary.

[Relationships between smoking and eating habits or behavior in male students].

OBJECTIVE: The aim of this study was to investigate relationships between smoking and eating habits or behavior in male students. METHODS: We performed a questionnaire regarding smoking, eating habits, eating behavior, and the frequency of food intake for 277 male students. We also measured bone mass by a quantitative ultrasound device, along with height, weight, body fat, and gripping power. RESULTS: The percentage of students who had a smoking habit was 22.4%. No significant differences in physical factors between the smoker and non-smoker groups were observed. However, there was significant variation for having meals regularly, and for the habit of assessing their own eating behavior (both P < 0.05). The percentage of students who wanted to obtain nutritional support for maintaining their health, or desiring nutritional support in order to keep a good body style was significantly lower in the smoker group compared to the non-smoker group (P < 0.05, respectively). Moreover, the percentage of students who had a habit of drinking alcohol or skipping meals was significantly higher in the smoker group (P = 0.002). In addition, the percentage of smoking students who had a habit of exercise was significantly lower (P < 0.001). CONCLUSION: In this study, we obtained useful data regarding relationships between smoking and eating habits in male students. These results suggested that appropriate nutritional education is important in the smoker group of male students for promotion of their health.

Effects of dietary lactose on long-term high-fat-diet-induced obesity in rats.

OBJECTIVE: In this study, we examined the effects of lactose on long-term high-fat-diet-induced obesity in rats. RESEARCH METHODS AND PROCEDURES: A total of 112 Sprague-Dawley strain female rats (6 weeks old) were divided into four groups: a basic control diet group (Cont), 10% lactose diet group (Lac), high-fat diet group (Fat), and high-fat with 10% lactose diet group (Fat+Lac). After 0, 7, 14, and 84 days from starting the experimental diet, the animals were fasted overnight and killed by bleeding from the abdominal aorta under anesthesia (n = 8 or 9/group). RESULTS: After 84 days, the addition of lactose to the high-fat diet decreased the final body weight, body weight gain, fat accumulation, and the levels of serum leptin, serum triglycerides, and serum glucose significantly (p < 0.05). Although there was no significant difference in the levels of serum calcium and phosphorus between the Fat and Fat+Lac groups, lumbar vertebral bone mineral density was significantly higher in the Fat+Lac group than in the Cont group on Day 82. Interestingly, the level of serum 1alpha, 25-dihydroxyvitamin D(3) in the Fat+Lac group on Day 84 was reduced by 74% compared with the Fat group (p < 0.01), while there was no significant difference in serum parathyroid hormone levels between the Fat and Fat+Lac groups. DISCUSSION: This is the first study to suggest that the addition of lactose to a long-term high-fat diet may regulate not only calcium metabolism but also fat deposition. Further studies on the mechanism of dietary lactose in the regulation of adiposity would provide valuable data for the prevention of long-term high-fat-diet-induced obesity.

Nutritional effects of gamma-glutamyl carboxylase gene polymorphism on the correlation between the vitamin K status and gamma-carboxylation of osteocalcin in young males.

Vitamin K is a cofactor for gamma-glutamyl carboxylase (GGCX), which is an essential enzyme for the gamma-carboxylation of vitamin K-dependent proteins such as osteocalcin (OC). Associations among dietary vitamin K intake, vitamin K status, and bone metabolism have not been thoroughly investigated. Recently, it has been reported that single nucleotide polymorphisms of GGCX (R325Q, 974G>A) were associated with age-related bone loss and the kinetic affinity for the substrate. In the present study, we investigated the associations among dietary vitamin K intake, the level of serum vitamin K, and the ratio of undercarboxylated OC (ucOC) to intact OC. The subjects were 60 healthy young male volunteers (mean age, 22.6 y; standard deviation, 1.6). Dietary nutrient intake was assessed by consecutive individual 3-d food records taken before the day of blood examinations. Serum concentrations of vitamin K (phylloquinone: PK, menaquinone 4: MK-4, and menaquinone 7: MK-7), ucOC, and intact OC were measured. All subjects were genotyped for polymorphism (R325Q) presence. Dietary vitamin K intake from vegetables was significantly correlated with the level of serum PK, and vitamin K intake from fermented beans, natto, was also significantly correlated with the level of serum MK-7. The ratio of ucOC to intact OC showed a negative association with the total vitamin K intake (r=-0.331, p=0.010) and serum MK-7 (r=-0.394, p=0.002). Interestingly, grouped by the GGCX genotype, a significant interaction between the ratio of ucOC to intact OC with serum MK-7 was observed in 325R homozygotes (r=-0.572, p=0.003), but not in heterozygotes, nor in 325Q homozygotes. This is the first report to suggest the effects of the single nucleotide polymorphism R325Q in the GGCX gene on the correlation between the level of serum MK-7 and gamma-carboxylation of serum OC.

Enhancement effects of vitamin K1 (phylloquinone) or vitamin K2 (menaquinone-4) on intestinal alkaline phosphatase activity in rats.

Alkaline phosphatase (ALP) hydrolyzes a variety of monophosphate esters into inorganic phosphoric acid and alcohol at a high optimal pH, and is thought to play an important role in phosphate metabolism. Intestinal ALP, located at the brush border of intestinal epithelial cells, is known to be affected by several kinds of nutrients, but little is known about the physiological function of intestinal ALP Vitamin K is an essential cofactor for the post-translational carboxylation of glutamate residues into gamma-carboxy glutamate (Gla). Recently, novel functions of vitamin K have been clarified, but no data exist on the relation between vitamin K and intestinal ALP. The aim of this study was to examine the effects of both vitamin Ks (K1: phylloquinone, and K2: menaquinone) on ALP activity. Sprague-Dawley rats (6-wk-old) were divided into three groups: a control, phylloquinone (PK: 600 mg/kg diet), or menaquinone-4 (MK-4: 600 mg/kg diet) diet group. After 3 mo of feeding, we measured intestinal ALP activity by dividing it into five segments. In each segment, both PK and MK-4 increased intestinal ALP activity. The levels of intestinal ALP activity in the duodenum and proximal jejunum from the PK group were significantly higher than in the control group (p < 0.05). Moreover, the levels of intestinal ALP activity from the proximal jejunum and distal ileum of the intestine in the MK group were significantly higher than in the control group (p < 0.05). In this study, we clarified for the first time that both vitamin K1 and K2 as nutritional factors enhance intestinal ALP activity.