Category Archives: Minerals

Silicon Increases Osteoblasts and Decreases Osteoclasts in Ovariectomized Rats

Abstract

Short-term effects of organic silicon on trabecular bone in mature ovariectomized rats.

Silicon is known to ensure an essential role in the formation of cross-links between collagen and proteoglycans during bone growth. In this study, we have evaluated the short-term effects of a preventive treatment with silanol, a soluble organic silicon (Si), on trabecular bone in mature ovariectomized rats. Three-month-old rats were sham-operated (sham) or were ovariectomized (OVX) and treated with 10 micrograms/kg/day of 17 beta estradiol (E2), or with 0.1 mg Si/kg/day or 1.0 mg Si/kg/day of silanol for 1 month. Plasma alkaline phosphatase and osteocalcin levels were increased by 50% in OVX rats compared with sham rats and were corrected by E2 but not by silanol treatment. The trabecular bone volume measured at the tibial metaphysis was decreased by 48%, and histomorphometric indices of bone resorption and formation were increased in OVX rats compared with sham, and these parameters were corrected by E2 treatment. Treatment of OVX rats with silanol decreased the osteoclast surface by 31% and the number of osteoclasts by 20%. The mineral apposition rate, the bone formation rate, and the osteoblast surface at the tibia metaphyseal area were increased by 30% at the higher dose of silanol compared with OVX rats. In contrast, silanol treatment had no effect on the periosteal apposition rate. The reduction of the metaphyseal bone resorption and the increased bone formation induced by silanol resulted in a slight improvement of the trabecular bone volume (+14%) compared with controls.

Hott M, de Pollak C, Modrowski D, Marie PJ
Calcif. Tissue Int. Sep 1993
PMID: 8242469

Silicon is Required for Bone Formation in Chicks

Abstract

Silicon: a requirement in bone formation independent of vitamin D1.

Silicon has been reported to be involved in an early stage of bone formation as a result of earlier in vitro and in vivo studies in this laboratory. It is now possible to demonstrate that silicon exerts an effect on bone formation independent of the action of vitamin D. Day-old cockerels were fed Si-deficient and Si-supplemented diets with adequate and no dietary vitamin D under trace element controlled conditions. At the end of 4 weeks chicks receiving dietary vitamin D3 (600 IU) exhibited optimal rates of growth whereas the growth rates of chicks receiving D2 (6000 IU) and no vitamin D were markedly depressed. There were no significant differences between growth of Si-deficient and Si-supplemented chicks on the same level of vitamin D. Skull and bone size was proportional to overall chick growth. However, all chicks on Si-deficient diets irrespective of the level of dietary vitamin D had gross abnormalities of skull architecture, the overall skull appearance being narrower and shorter. The frontal area was narrower and the dorsal median line at the front parietal junction was depressed with a narrowing both posterior and laterally, stunting parietal and occipital areas. These abnormal areas showed fewer trabeculae and less calcification. Analyses of skull frontal bones for hexosamine, collagen, noncollagenous protein, and bone mineral demonstrated that the major difference was in collagen content, the Si-deficient skulls showing considerably less collagen at each level of vitamin D. These findings demonstrate that silicon has a significant effect on the bone matrix independent of vitamin D, and support the earlier postulate that silicon is involved in an early stage of bone formation.

Carlisle EM
Calcif. Tissue Int. 1981
PMID: 6257332

Orthosilicic Acid Stimulates Bone Formation in Osteopenic Women

Abstract

Choline-stabilized orthosilicic acid supplementation as an adjunct to calcium/vitamin D3 stimulates markers of bone formation in osteopenic females: a randomized, placebo-controlled trial.

Mounting evidence supports a physiological role for silicon (Si) as orthosilicic acid (OSA, Si(OH)4) in bone formation. The effect of oral choline-stabilized orthosilicic acid (ch-OSA) on markers of bone turnover and bone mineral density (BMD) was investigated in a double-blind placebo-controlled trial.
Over 12-months, 136 women out of 184 randomized (T-score spine < -1.5) completed the study and received, daily, 1000 mg Ca and 20 microg cholecalciferol (Vit D3) and three different ch-OSA doses (3, 6 and 12 mg Si) or placebo. Bone formation markers in serum and urinary resorption markers were measured at baseline, and after 6 and 12 months. Femoral and lumbar BMD were measured at baseline and after 12 months by DEXA.
Overall, there was a trend for ch-OSA to confer some additional benefit to Ca and Vit D3 treatment, especially for markers of bone formation, but only the marker for type I collagen formation (PINP) was significant at 12 months for the 6 and 12 mg Si dose (vs. placebo) without a clear dose response effect. A trend for a dose-corresponding increase was observed in the bone resorption marker, collagen type I C-terminal telopeptide (CTX-I). Lumbar spine BMD did not change significantly. Post-hoc subgroup analysis (baseline T-score femur < -1) however was significant for the 6 mg dose at the femoral neck (T-test). There were no ch-OSA related adverse events observed and biochemical safety parameters remained within the normal range.
Combined therapy of ch-OSA and Ca/Vit D3 had a potential beneficial effect on bone collagen compared to Ca/Vit D3 alone which suggests that this treatment is of potential use in osteoporosis.

Spector TD, Calomme MR, Anderson SH, Clement G…
BMC Musculoskelet Disord 2008
PMID: 18547426 | Free Full Text


From the full text:

Collagen provides elasticity and structure in all connective tissues and several studies have indicated that collagen is important for bone toughness [43-45] whereas the mineral component is mainly involved in providing stiffness. Wang et al. [46] demonstrated that the mechanical integrity of collagen fibres deteriorates with ageing in human cortical bones and is associated with a higher fracture risk. When the collagen network becomes weaker with age, it will result in decreased toughness, possibly due to a reduction in natural cross-links or silicon content. It has previously been suggested that Si may be an integral (structural) component of connective tissues as high levels of non-dialysable Si has been reported in connective tissues and their components suggesting strong (covalent) associations [47].

Orthosilicic Acid Increases Bone Density in Ovariectomized Rats

Abstract

Partial prevention of long-term femoral bone loss in aged ovariectomized rats supplemented with choline-stabilized orthosilicic acid.

Silicon (Si) deficiency in animals results in bone defects. Choline-stabilized orthosilicic acid (ch-OSA) was found to have a high bioavailability compared to other Si supplements. The effect of ch-OSA supplementation was investigated on bone loss in aged ovariectomized (OVX) rats. Female Wistar rats (n = 58, age 9 months) were randomized in three groups. One group was sham-operated (sham, n = 21), and bilateral OVX was performed in the other two groups. OVX rats were supplemented orally with ch-OSA over 30 weeks (OVX1, n = 20; 1 mg Si/kg body weight daily) or used as controls (OVX0, n = 17). The serum Si concentration and the 24-hour urinary Si excretion of supplemented OVX rats was significantly higher compared to sham and OVX controls. Supplementation with ch-OSA significantly but partially reversed the decrease in Ca excretion, which was observed after OVX. The increase in bone turnover in OVX rats tended to be reduced by ch-OSA supplementation. ch-OSA supplementation increased significantly the femoral bone mineral content (BMC) in the distal region and total femoral BMC in OVX rats, whereas lumbar BMC was marginally increased. Femoral BMD was significantly increased at two sites in the distal region in OVX rats supplemented with ch-OSA compared to OVX controls. Total lumbar bone mineral density was marginally increased by ch-OSA supplementation. In conclusion, ch-OSA supplementation partially prevents femoral bone loss in the aged OVX rat model.

Calomme M, Geusens P, Demeester N, Behets GJ…
Calcif. Tissue Int. Apr 2006
PMID: 16604283

Orthosilicic Acid Stimulates Collagen and Osteoblasts In Vitro

Abstract

Orthosilicic acid stimulates collagen type 1 synthesis and osteoblastic differentiation in human osteoblast-like cells in vitro.

Silicon deficiency in animals leads to bone defects. This element may therefore play an important role in bone metabolism. Silicon is absorbed from the diet as orthosilicic acid and concentrations in plasma are 5-20 microM. The in vitro effects of orthosilicic acid (0-50 microM) on collagen type 1 synthesis was investigated using the human osteosarcoma cell line (MG-63), primary osteoblast-like cells derived from human bone marrow stromal cells, and an immortalized human early osteoblastic cell line (HCC1). Collagen type 1 mRNA expression and prolyl hydroxylase activity were also determined in the MG-63 cells. Alkaline phosphatase and osteocalcin (osteoblastic differentiation) were assessed both at the protein and the mRNA level in MG-63 cells treated with orthosilicic acid. Collagen type 1 synthesis increased in all treated cells at orthosilicic acid concentrations of 10 and 20 microM, although the effects were more marked in the clonal cell lines (MG-63, HCCl 1.75- and 1.8-fold, respectively, P < 0.001, compared to 1.45-fold in the primary cell lines). Treatment at 50 microM resulted in a smaller increase in collagen type 1 synthesis (MG-63 1.45-fold, P = 0.004). The effect of orthosilicic acid was abolished in the presence of prolyl hydroxylase inhibitors. No change in collagen type 1 mRNA level was seen in treated MG-63 cells. Alkaline phosphatase activity and osteocalcin were significantly increased (1.5, 1.2-fold at concentrations of 10 and 20 microM, respectively, P < 0.05). Gene expression of alkaline phosphatase and osteocalcin also increased significantly following treatment. In conclusion, orthosilicic acid at physiological concentrations stimulates collagen type 1 synthesis in human osteoblast-like cells and enhances osteoblastic differentiation.

Reffitt DM, Ogston N, Jugdaohsingh R, Cheung HF…
Bone Feb 2003
PMID: 12633784

Review: Silicon

Abstract

Silicon and bone health.

Low bone mass (osteoporosis) is a silent epidemic of the 21st century, which presently in the UK results in over 200,000 fractures annually at a cost of over one billion pounds. Figures are set to increase worldwide. Understanding the factors which affect bone metabolism is thus of primary importance in order to establish preventative measures or treatments for this condition. Nutrition is an important determinant of bone health, but the effects of the individual nutrients and minerals, other than calcium, is little understood. Accumulating evidence over the last 30 years strongly suggest that dietary silicon is beneficial to bone and connective tissue health and we recently reported strong positive associations between dietary Si intake and bone mineral density in US and UK cohorts. The exact biological role(s) of silicon in bone health is still not clear, although a number of possible mechanisms have been suggested, including the synthesis of collagen and/or its stabilization, and matrix mineralization. This review gives an overview of this naturally occurring dietary element, its metabolism and the evidence of its potential role in bone health.

Jugdaohsingh R
J Nutr Health Aging
PMID: 17435952 | Free Full Text

Strontium Ranelate Associated with Unfavorable Cardiac Risk

Abstract

Nationwide registry-based analysis of cardiovascular risk factors and adverse outcomes in patients treated with strontium ranelate.

National registers showed that a large proportion of patients treated with strontium ranelate have conditions that may now contraindicate use. The risk of death in strontium ranelate-treated patients was significantly higher than that seen in users of other osteoporosis drugs even after adjusting for cardiovascular risk factor profile.
The European Medicines Agency (EMA) recently warned that strontium ranelate should be avoided in patients with ischaemic heart disease (IHD), peripheral vascular disease (PVD) or cerebrovascular disease (CVD), and in patients with uncontrolled hypertension. We investigated to what extent patients beginning strontium ranelate had cardiovascular conditions and determined the rates of MI, stroke and death.
Using the Danish National Prescription Database, we identified all 3,252 patients aged 50+ who began strontium ranelate in 2005-2007 and 35,606 users of other osteoporosis drugs as controls. Hospital contacts and causes of death were retrieved from national registers.
Patients starting strontium were older than patients treated with other osteoporosis drugs and more likely to suffer from IHD, PVD or CVD (combined prevalence 19.2 % in female users and 29.5 % in male users). The adjusted risk of MI was not significantly increased (women: HR 1.05 [95 % CI 0.79-1.41, p = 0.73]; men: 1.28 [0.74-2.20, p = 0.38]). For stroke, the adjusted HR was 1.23 (0.98-1.55, p = 0.07) in women and 1.64 (0.99-2.70, p = 0.05) in men. All-cause mortality was higher in strontium users (women: adjusted HR 1.20 [1.10-1.30, p < 0.001]; men: adjusted HR 1.22 [1.03-1.45, p < 0.05]).
Patients treated with strontium ranelate have an unfavourable cardiovascular risk profile compared with users of other osteoporosis drugs. However, only the risk of death differed significantly from the rates observed in users of other osteoporosis drugs adjusted for risk factor profile. A large proportion of patients currently treated with strontium ranelate have conditions that would now be considered contraindications according to EMA.

Abrahamsen B, Grove EL, Vestergaard P
Osteoporos Int Feb 2014
PMID: 24322475

Strontium Ranelate Not Associated with Heart Attacks or Other Cardiac Events

Abstract

Ischaemic cardiac events and use of strontium ranelate in postmenopausal osteoporosis: a nested case-control study in the CPRD.

We explored the cardiac safety of the osteoporosis treatment strontium ranelate in the UK Clinical Practice Research Datalink. While known cardiovascular risk factors like obesity and smoking were associated with increased cardiac risk, use of strontium ranelate was not associated with any increase in myocardial infarction or cardiovascular death.
It has been suggested that strontium ranelate may increase risk for cardiac events in postmenopausal osteoporosis. We set out to explore the cardiac safety of strontium ranelate in the Clinical Practice Research Datalink (CPRD) and linked datasets.
We performed a nested case-control study. Primary outcomes were first definite myocardial infarction, hospitalisation with myocardial infarction, and cardiovascular death. Cases and matched controls were nested in a cohort of women treated for osteoporosis. The association with exposure to strontium ranelate was analysed by multivariate conditional logistic regression.
Of the 112,445 women with treated postmenopausal osteoporosis, 6,487 received strontium ranelate. Annual incidence rates for first definite myocardial infarction (1,352 cases), myocardial infarction with hospitalisation (1,465 cases), and cardiovascular death (3,619 cases) were 3.24, 6.13, and 14.66 per 1,000 patient-years, respectively. Obesity, smoking, and cardiovascular treatments were associated with significant increases in risk for cardiac events. Current or past use of strontium ranelate was not associated with increased risk for first definite myocardial infarction (odds ratio [OR] 1.05, 95 % confidence interval [CI] 0.68-1.61 and OR 1.12, 95 % CI 0.79-1.58, respectively), hospitalisation with myocardial infarction (OR 0.84, 95 % CI 0.54-1.30 and OR 1.17, 95 % CI 0.83-1.66), or cardiovascular death (OR 0.96, 95 % CI 0.76-1.21 and OR 1.16, 95 % CI 0.94-1.43) versus patients who had never used strontium ranelate.
Analysis in the CPRD did not find evidence for a higher risk for cardiac events associated with the use of strontium ranelate in postmenopausal osteoporosis.

Cooper C, Fox KM, Borer JS
Osteoporos Int Feb 2014
PMID: 24322476 | Free Full Text

Boron Increases Strength and Bone Minerals in Rabbits

Abstract

Boron enhances strength and alters mineral composition of bone in rabbits fed a high energy diet.

An experiment was performed to determine whether boron had a beneficial effect on bone strength and composition in rabbits with apparent adiposity induced by a high energy diet. Sixty female New Zealand rabbits, aged 8 months, were randomly divided into five groups with the following treatments for seven months: control 1, fed alfalfa hay only (5.91 MJ/kg); control 2, high energy diet (11.76 MJ and 3.88 mg boron/kg); B10, high energy diet+10 mg/kg body weight boron gavage/96 h; B30, high energy diet+30 mg/kg body weight boron gavage/96 h; B50, high energy diet+50mg/kg body weight boron gavage/96 h. Bone boron concentrations were lowest in rabbits fed the high energy diet without boron supplementation, which suggested an inferior boron status. Femur maximum breaking force was highest in the B50 rabbits. Tibia compression strength was highest in B30 and B50 rabbits. All boron treatments significantly increased calcium and magnesium concentrations, and the B30 and B50 treatments increased the phosphorus concentration in tibia of rabbits fed the high energy diet. The B30 treatment significantly increased calcium, phosphorus and magnesium concentrations in femur of rabbits fed the high energy diet. Principal component analysis of the tibia minerals showed that the three boron treatments formed a separate cluster from controls. Discriminant analysis suggested that the concentrations of the minerals in femur could predict boron treatment. The findings indicate boron has beneficial effects on bone strength and mineral composition in rabbits fed a high energy diet.

Hakki SS, Dundar N, Kayis SA, Hakki EE…
J Trace Elem Med Biol Apr 2013
PMID: 22944583

Review: Calcium Safety and New Recommendations

Abstract

Calcium builds strong bones, and more is better–correct? Well, maybe not.

Calcium supplementation has been considered the gold standard therapy for osteoporosis in the general population. It is given in both the placebo and treatment groups of trials evaluating antifracture efficacy of new therapies. Similarly, calcium-based phosphate binders have been considered the gold standard comparator for all new phosphate binders. However, large randomized trials demonstrate conflicting data on the antifracture efficacy of calcium supplementation, particularly in high doses, in patients with osteoporosis without CKD. In addition, recent data suggest an increased risk for cardiovascular events. These new studies raise safety concerns for the general approach with calcium supplementation and binders. This review describes recent data on the adverse effects of calcium supplementation for osteoporosis and how these new data should affect the strategy for phosphate binder use in CKD.

Jamal SA, Moe SM
Clin J Am Soc Nephrol Nov 2012
PMID: 22837272 | Free Full Text


It is important to note that some clinical practice guidelines have been modified on the basis of this new literature suggesting potential risk. For example, in its recently published evidence-based guidelines, Osteoporosis Canada recommended a total intake of calcium (from diet and supplement) of 1200 mg per day, a decrease from the previous recommendation of 1500 mg in supplements (32). The American Society for Bone and Mineral Research issued a statement regarding the potential risks of calcium supplements and suggested, among other points, that “the beneficial effects of calcium are found with relatively low doses. More is not necessarily better. Individuals should discuss the amount of their calcium intake with their healthcare provider” (33). The Institute of Medicine now recommends a daily dietary reference allowance of calcium of 1000–1200 mg per day in the form of diet and supplements (34,35). Finally, the draft United States Preventive Services Task Force statement, pending public comment (http://www.uspreventiveservicestaskforce.org/draftrec3.htm), currently states “the current evidence is insufficient to assess the balance of the benefits and harms of combined vitamin D and calcium supplementation for the primary prevention of fractures in premenopausal women or in men.” Thus, these authorities acknowledge that although some calcium supplements may be beneficial for bone health, too much calcium may be harmful.