Tag Archives: free full text

Magnesium Not Associated with Bone Mass in Young Women

Abstract

Magnesium intake and bone mineral density in young adult women.

The purpose of this study was to determine a possible association between magnesium intake and bone mass in young adult women. Subjects consisted of 106 female university students aged 19-25 years. Calcium and magnesium intakes were evaluated using the duplicate sampling method on three weekdays. Spinal and femoral bone mineral density (BMD) was measured by dual energy X-ray absorptiometry. Mean magnesium intake was 139 mg/day (median 127, SD 54). The correlation between magnesium intake and BMD was of borderline significance (r = 0.175, p = 0.073) for the femoral neck, and was insignificant (r = 0.084, p = 0.391) for the lumbar spine. However, the partial correlation between magnesium intake and BMD of the femoral neck (r = -0.027, p = 0.788), adjusted for calcium intake, was not significant. In conclusion, we did not find an association between magnesium intake and bone mass in young women, and calcium intake needs to be included as an important, potential confounding factor when exploring such an association.

Nakamura K, Ueno K, Nishiwaki T, Saito T…
Magnes Res Dec 2007
PMID: 18271495 | Free Full Text

Magnesium in Bone is Higher When Taken More Frequently in Rats

Abstract

The frequency of magnesium consumption directly influences its serum concentration and the amount of elutable bone magnesium in rats.

We investigated the influence of Mg feeding frequency on the variation in serum Mg concentration and tissue Mg levels in Mg-deficient rats. Sprague-Dawley rats, which had been fed a Mg-deficient diet for 14 d, were divided into 3 groups that were kept on 3 diets differing in their Mg content. The rats were fed 0.5-fold (Mg250 group), 1-fold (Mg500 group), or 1.5-fold (Mg750 group) the amounts of recommended Mg in their standard AIN-93G diet (Mg: 478 mg/kg diet) during the recovery period (12 d). The Mg500 and Mg750 groups were intermittently fed (Mg500, every 2 d; Mg750, every 3 d) so that their total intake of Mg during the recovery period could equal the Mg intake of the Mg250 group. The serum Mg concentrations increased in the 3 groups after feeding with a Mg-containing diet. However, serum Mg levels were only maintained within the normal range in the Mg250 group. After feeding on the Mg-deficient diet, in the intermittently fed groups, serum Mg concentrations decreased. Urinary Mg excretion was higher and Mg retention was lower in the Mg500 and Mg750 groups than in the Mg250 group. Moreover, bone Mg, especially elutable bone Mg, was lower in the Mg500 and Mg750 groups than in the Mg250 group. The elutable fraction of bone Mg correlated to the coefficient of variation of serum Mg concentration. In conclusion, for the maintenance of serum Mg concentration, it is important to increase the amount of elutable bone Mg by frequent Mg consumption.

Nakaya Y, Uehara M, Katsumata S, Suzuki K…
Magnes Res Mar 2010
PMID: 20228011 | Free Full Text

Note the rats that ate 250mg/kg Magnesium had higher bone Magnesium than the rats fed just as much Magnesium but less often, every 2 or 3 days.

Magnesium Suppresses Bone Resorption Rats Fed a High-Phosphorus Diet

Abstract

Dietary magnesium supplementation suppresses bone resorption via inhibition of parathyroid hormone secretion in rats fed a high-phosphorus diet.

This study examined the effects of dietary magnesium (Mg) supplementation on bone turnover and serum parathyroid hormone (PTH) levels in rats fed a high-phosphorus (P) diet. Male rats were randomized by weight into three groups, and fed a control diet (control), a high-P diet (HP) or a high-P and high-Mg diet (HPHMg) for 14 days. Serum osteocalcin levels were significantly higher in the HP and HPHMg groups than in the control group. Serum CTx levels were significantly higher in the HP and HPHMg groups than in the control group, while the levels in the HPHMg group were significantly lower than in the HP group. Serum PTH levels were significantly higher in the HP group than in the control and HPHMg groups. Dietary Mg supplementation had a significant influence on serum PTH levels in the HP and HPHMg groups. These results suggest that dietary Mg supplementation suppresses the high bone resorption induced by a high-P diet via inhibition of PTH secretion. Moreover, our results suggest that dietary Mg supplementation may be beneficial for the prevention of bone loss with high-P diet administration.

Matsuzaki H, Fuchigami M, Miwa M
Magnes Res Sep 2010
PMID: 20810356 | Free Full Text

Magnesium Water No Benefit in Postmenopausal Women

Abstract

A double-blind, placebo-controlled study of the short term effects of a spring water supplemented with magnesium bicarbonate on acid/base balance, bone metabolism and cardiovascular risk factors in postmenopausal women.

A number of health benefits including improvements in acid/base balance, bone metabolism, and cardiovascular risk factors have been attributed to the intake of magnesium rich alkaline mineral water. This study was designed to investigate the effects of the regular consumption of magnesium bicarbonate supplemented spring water on pH, biochemical parameters of bone metabolism, lipid profile and blood pressure in postmenopausal women. In this double-blind, placebo-controlled, parallel-group, study, 67 postmenopausal women were randomised to receive between 1500 mL and 1800 mL daily of magnesium bicarbonate supplemented spring water (650 mg/L bicarbonate, 120 mg/L magnesium, pH 8.3-8.5) (supplemented water group) or spring water without supplements (control water group) over 84 days. Over this period biomarkers of bone turnover (serum parathyroid hormone (PTH), 1,25-dihydroxyvitamin D, osteocalcin, urinary telopeptides and hydroxyproline), serum lipids (total cholesterol, HDL-cholesterol, LDL-cholesterol and triglycerides), venous and urinary pH were measured together with measurements of standard biochemistry, haematology and urine examinations. Serum magnesium concentrations and urinary pH in subjects consuming the magnesium bicarbonate supplemented water increased significantly at Day 84 compared to subjects consuming the spring water control (magnesium – p = 0.03; pH – p = 0.018). The consumption of spring water led to a trend for an increase in parathyroid hormone (PTH) concentrations while the PTH concentrations remained stable with the intake of the supplemented spring water. However there were no significant effects of magnesium bicarbonate supplementation in changes to biomarkers of bone mineral metabolism (n-telopeptides, hydroxyproline, osteocalcin and 1,25-dihydroxyvitamin D) or serum lipids or blood pressure in postmenopausal women from Day 0 to Day 84.
Short term regular ingestion of magnesium bicarbonate supplemented water provides a source of orally available magnesium. Long term clinical studies are required to investigate any health benefits.

Day RO, Liauw W, Tozer LM, McElduff P…
BMC Res Notes 2010
PMID: 20579398 | Free Full Text

The acid/base theory is questionable and this was a low dose of Magnesium.

Comment: Cycling and bone health: a systematic review

Abstract

Bike racing, recreational riding, impact sport and bone health.

Cycling has been shown to confer considerable benefits in terms of health, leading to reductions in death rates principally due to cardiovascular improvements and adaptation. Given the disparity between the benefits of cycling on cardiovascular fitness and previous research finding that cycling may not be beneficial for bone health, Hugo Olmedillas and colleagues performed a systematic review of the literature. They concluded that road cycling does not appear to confer any significant osteogenic benefit. They postulate that the cause of this is that, particularly at a competitive level, riders spend long periods of time in a weight-supported position on the bike. Training programs may be supplemented with impact loading to preserve bone health; however, the small increased risk of soft tissue injury must also be considered. See related study.

Carmont MR
BMC Med 2012
PMID: 23256478 | Free Full Text

Review: Cyclists Have Low Bone Density

Abstract

Cycling and bone health: a systematic review.

Cycling is considered to be a highly beneficial sport for significantly enhancing cardiovascular fitness in individuals, yet studies show little or no corresponding improvements in bone mass.
A scientific literature search on studies discussing bone mass and bone metabolism in cyclists was performed to collect all relevant published material up to April 2012. Descriptive, cross-sectional, longitudinal and interventional studies were all reviewed. Inclusion criteria were met by 31 studies.
Heterogeneous studies in terms of gender, age, data source, group of comparison, cycling level or modality practiced among others factors showed minor but important differences in results. Despite some controversial results, it has been observed that adult road cyclists participating in regular training have low bone mineral density in key regions (for example, lumbar spine). Conversely, other types of cycling (such as mountain biking), or combination with other sports could reduce this unsafe effect. These results cannot yet be explained by differences in dietary patterns or endocrine factors.
From our comprehensive survey of the current available literature it can be concluded that road cycling does not appear to confer any significant osteogenic benefit. The cause of this may be related to spending long hours in a weight-supported position on the bike in combination with the necessary enforced recovery time that involves a large amount of time sitting or lying supine, especially at the competitive level.

Olmedillas H, González-Agüero A, Moreno LA, Casajus JA…
BMC Med 2012
PMID: 23256921 | Free Full Text

Vitamin K1 Associated With Bone Health in Women

Abstract

Vitamin K1 intake is associated with higher bone mineral density and reduced bone resorption in early postmenopausal Scottish women: no evidence of gene-nutrient interaction with apolipoprotein E polymorphisms.

Polymorphisms in the apolipoprotein E (APOE) gene are associated with fracture risk, and a potential mechanism is through vitamin K transport.
We investigated the relation between dietary vitamin K(1) intake, APOE polymorphisms, and markers of bone health. We measured bone mineral density (BMD) at the lumbar spine (LS) and femoral neck (FN) in a cohort of Scottish women aged 49-54 y in 1990-1994 (baseline) and in 1997-2000 (visit 2). At visit 2, bone markers (urinary pyridinoline crosslinks and serum N-terminal propeptide of type 1 collagen) were measured, 3199 women completed a food-frequency questionnaire, and 2721 women were genotyped for APOE.
Compared with quartile 3 (Q3) of energy-adjusted vitamin K(1) intake (mean: 116 microg/d), women in the lowest quartile (mean: 59 microg/d) had lower BMD (analysis of variance; FN, Q1: 0.831 +/- 0.122 g/cm(2); Q3: 0.850 +/- 0.126 g/cm(2); P < 0.001; LS, Q1: 1.000 +/- 0.170 g/cm(2); Q3: 1.020 +/- 0.172 g/cm(2); P = 0.009), remaining significant at the FN after adjustment for age, weight, height, menopausal status or use of hormone replacement therapy, socioeconomic status, and physical activity (P = 0.04). Vitamin K(1) intake was associated with reduced concentrations of pyridinoline crosslinks (Q1: 5.4 +/- 2.0 nmol/mmol; Q4: 5.1 +/- 1.9 nmol/mmol; P = 0.003). Carriers of the E2 allele had greater LS BMD at visit 2 and lost less BMD than did carriers of the E4 allele (E2: -0.50 +/- 1.22%/y; E4: -0.71 +/- 1.17%/y; P = 0.05). After adjustment for confounders, the P value for BMD loss (0.03 for LS and 0.04 for FN) did not reach the level of significance required for multiple testing (P = 0.012). No interaction was observed between dietary vitamin K and APOE on BMD.
Vitamin K(1) intake was associated with markers of bone health, but no interaction was observed with APOE alleles on BMD or markers of bone turnover.

Macdonald HM, McGuigan FE, Lanham-New SA, Fraser WD…
Am. J. Clin. Nutr. May 2008
PMID: 18469278 | Free Full Text

Vitamin K1 May Help Prevent Fractures, But Does Not Improve Bone Density in Women with Osteopenia

Abstract

Vitamin K supplementation in postmenopausal women with osteopenia (ECKO trial): a randomized controlled trial.

Vitamin K has been widely promoted as a supplement for decreasing bone loss in postmenopausal women, but the long-term benefits and potential harms are unknown. This study was conducted to determine whether daily high-dose vitamin K1 supplementation safely reduces bone loss, bone turnover, and fractures.
This single-center study was designed as a 2-y randomized, placebo-controlled, double-blind trial, extended for earlier participants for up to an additional 2 y because of interest in long-term safety and fractures. A total of 440 postmenopausal women with osteopenia were randomized to either 5 mg of vitamin K1 or placebo daily. Primary outcomes were changes in BMD at the lumbar spine and total hip at 2 y. Secondary outcomes included changes in BMD at other sites and other time points, bone turnover markers, height, fractures, adverse effects, and health-related quality of life. This study has a power of 90% to detect 3% differences in BMD between the two groups. The women in this study were vitamin D replete, with a mean serum 25-hydroxyvitamin D level of 77 nmol/l at baseline. Over 2 y, BMD decreased by -1.28% and -1.22% (p = 0.84) (difference of -0.06%; 95% confidence interval [CI] -0.67% to 0.54%) at the lumbar spine and -0.69% and -0.88% (p = 0.51) (difference of 0.19%; 95% CI -0.37% to 0.75%) at the total hip in the vitamin K and placebo groups, respectively. There were no significant differences in changes in BMD at any site between the two groups over the 2- to 4-y period. Daily vitamin K1 supplementation increased serum vitamin K1 levels by 10-fold, and decreased the percentage of undercarboxylated osteocalcin and total osteocalcin levels (bone formation marker). However, C-telopeptide levels (bone resorption marker) were not significantly different between the two groups. Fewer women in the vitamin K group had clinical fractures (nine versus 20, p = 0.04) and fewer had cancers (three versus 12, p = 0.02). Vitamin K supplements were well-tolerated over the 4-y period. There were no significant differences in adverse effects or health-related quality of life between the two groups. The study was not powered to examine fractures or cancers, and their numbers were small.
Daily 5 mg of vitamin K1 supplementation for 2 to 4 y does not protect against age-related decline in BMD, but may protect against fractures and cancers in postmenopausal women with osteopenia. More studies are needed to further examine the effect of vitamin K on fractures and cancers.

Cheung AM, Tile L, Lee Y, Tomlinson G…
PLoS Med. Oct 2008
PMID: 18922041 | Free Full Text

Low Dose MK-4 May Benefit Bones in Postmenopausal Japanese Women

Abstract

Effect of low dose vitamin K2 (MK-4) supplementation on bio-indices in postmenopausal Japanese women.

It has been reported that treatment with a pharmacological dose (45 mg/d) of menaquinone-4 (MK-4) prevents bone loss in postmenopausal women. However, it is not known whether supplementation with low dose MK-4 has beneficial effects on bone metabolism in healthy women. The aim of this study is to examine the effects of the supplementation of 1.5 mg/d MK-4 for 4 wk on bone and lipid metabolism in healthy postmenopausal Japanese women. The study was performed as a randomized double blind placebo-controlled trial. The participants aged 53-65 y were randomly assigned to 2 groups and supplemented with 1.5 mg/d of MK-4 or a placebo for 4 wk (n=20 for each group). The most marked effects of MK-4 intake were observed on serum osteocalcin (OC) concentrations. Serum undercarboxylated OC (ucOC) concentration decreased, and the gamma-carboxylated OC (GlaOC) and GlaOC/GlaOC+ucOC ratio that indicates the degree of OC gamma-carboxylation increased significantly at 2 and 4 wk compared with that at baseline in the MK-4 group. The serum ucOC and GlaOC concentrations in the MK-4 group were significantly different from those in the placebo group at 2 wk. These results suggest that supplementation with 1.5 mg/d MK-4 accelerated the degree of OC gamma-carboxylation. The concentrations of serum lipids and other indices were not different between the groups at either intervention period. Thus, the additional intake of MK-4 might be beneficial in the maintenance of bone health in postmenopausal Japanese women.

Koitaya N, Ezaki J, Nishimuta M, Yamauchi J…
J. Nutr. Sci. Vitaminol. Feb 2009
PMID: 19352059 | Free Full Text

In conclusion, our study clearly shows that the vitamin K status of postmenopausal women taking an extra dose of 1.5 mg MK-4 daily substantially improved after 4 wk. This improved satus was evidenced by the more than 1 ng/mL of serum MK-4 concentration. This suggests that increasing MK-4 intake by 1.5 mg/d led to an increase in the degree of γ-carboxylation of OC. Thus, the supplementation of low doses of vitamin K2 may favorably affect bone health in healthy postmenopausal women. It is desirable that the required amount of vitamin K be taken with daily meals.

Low Vitamin K Associated with Fracture, but not Bone Density, in Men and Women

Abstract

Dietary vitamin K intakes are associated with hip fracture but not with bone mineral density in elderly men and women.

Vitamin K has been associated with bone mineral density (BMD) and risk of hip fracture. The apolipoprotein (apo) E4 allele (APOE*E4) has been associated with bone fracture through a putative effect on vitamin K transport in blood.
The objective was to determine the associations between vitamin K intake, apo E genotype, BMD, and hip fracture in a population-based cohort of elderly men and women.
Dietary vitamin K intake was assessed with a food-frequency questionnaire in 335 men and 553 women (average age: 75.2 y) participating in the Framingham Heart Study in 1988-1989. Incidence of hip fractures was recorded from 1988 to 1995. BMD at the hip, spine, and arm was assessed on 2 separate occasions (1988-1989 and 1992-1993). Comparisons between apo E genotype and BMD were made relative to E4 allele status (at least 1 epsilon4 allele compared with no epsilon4 allele).
Individuals in the highest quartile of vitamin K intake (median: 254 microg/d) had a significantly lower fully adjusted relative risk (0.35; 95% CI: 0. 13, 0.94) of hip fracture than did those in the lowest quartile of intake (median: 56 microg/d). There were no associations between vitamin K intake and BMD in either men or women. No association was found between the E4 allele and BMD, and there were no significant interactions between the E4 allele and phylloquinone intake and BMD or hip fracture.
Low vitamin K intakes were associated with an increased incidence of hip fractures in this cohort of elderly men and women. Neither low vitamin K intake nor E4 allele status was associated with low BMD.

Booth SL, Tucker KL, Chen H, Hannan MT…
Am. J. Clin. Nutr. May 2000
PMID: 10799384 | Free Full Text