Category Archives: Minerals

Higher Sodium + Adequate Calcium is Not Detrimental for Bone in Women

Abstract

Higher habitual sodium intake is not detrimental for bones in older women with adequate calcium intake.

Based on the calciuric effect of sodium (Na), it has been speculated, although not proven, that higher Na intake might have a detrimental effect on bone health. The objective was to determine the relationship between Na intake (expressed as urinary Na) and bone mineral density/content (BMD/BMC) during a 3-year study. Participants were healthy, postmenopausal, Caucasian women (n = 136 at baseline) with no medications affecting bone. After baseline screening, half were instructed to reduce sodium intake to approximately 1,500 mg/day (intervention). The other half remained on habitual intake of approximately 3,000 mg/day (control). All subjects were given calcium and vitamin D supplements to achieve recommended levels. Anthropometries, densitometry, blood and 24-h urine analyses, and dietary and activity records were assessed every 6 months. Data were analyzed as a continuum, irrespective of the initial assignment to a control or intervention group, using random effects regressions with repeated measures analysis of variance to examine changes over time. Results showed that subjects with higher Na intake had higher BMD in the forearm and spine at baseline and all subsequent time-points (p < 0.01). In the forearm, time and higher urinary calcium modified results, producing a curvilinear decrease in BMD (p < 0.01). In the spine, more active individuals had higher BMD at all time-points. We conclude that higher sodium intake, within the range consumed, had a positive effect on some skeletal sites and no adverse effect on bone in women who had adequate calcium and vitamin D intake.

Ilich JZ, Brownbill RA, Coster DC
Eur. J. Appl. Physiol. Jul 2010
PMID: 20217116

Review: No Harm From Prevailing Sodium Intakes with Adequate Calcium

Abstract

Role of dietary sodium in osteoporosis.

Sodium, in the form of sodium chloride, elevates urinary calcium excretion and, at prevailing calcium intakes, evokes compensatory responses that may lead to increased bone remodeling and bone loss. The calciuria is partly due to salt-induced volume expansion, with an increase in GFR, and partly to competition between sodium and calcium ions in the renal tubule. Potassium intakes in the range of current recommendations actually reduce or prevent sodium chloride-induced calciuria. At calcium intakes at or above currently recommended levels, there appear to be no deleterious effects of prevailing salt intakes on bone or the calcium economy, mainly because adaptive increases in calcium absorption offset the increased urinary loss. Such compensation is likely to be incomplete at low calcium intakes. Limited evidence suggests equivalent bone-sparing effects of either salt restriction or augmented calcium intakes. Given the relative difficulty of the former, and the ancillary benefits of the latter, it would seem that the optimal strategy to protect the skeleton is to ensure adequate calcium and potassium intakes.

Heaney RP
J Am Coll Nutr Jun 2006
PMID: 16772639

Low Sodium may be Risk Factor for Maintaining Calcium and Magnesium

Abstract

Positive correlation between dietary intake of sodium and balances of calcium and magnesium in young Japanese adults–low sodium intake is a risk factor for loss of calcium and magnesium–.

The content of calcium (Ca) and magnesium (Mg) in sweat during exercise is considerably higher during a relatively low intake of sodium (Na) of 100 mmol/d than with an intake of 170 mmol/d. For this reason and also because Ca and Mg have a negative balance with a Na intake of 100 mmol/d, we analyzed the relationship between Na intake and balances of Ca and Mg in data from 11 balance studies. From 1986 to 2000, 109 volunteers (23 males, 86 females) with an age range of 18 to 28 y took part in mineral balance studies. The balance periods ranged from 5 to 12 d. In a given experiment, the diet of each subject contained the same quantity of food, although this varied between experiments, and was supplied during the balance period without consideration of body weight. In the data of all the studies (n= 109), the balances of Ca and Mg did not correlate positively with Na intake. However, when the data of the highest Na study were excluded, the balances of Ca and Mg correlated positively with Na intake. The mean value for the regression equation between Na intake and Ca and Mg balances when the respective balance was equal to zero were, 63.308 mg Na/kg BW/d (Ca: n=96, r2=0.134) and 60.977 mg Na/kg BW/d (Mg: n=96, r2=0.268), respectively. These values are considerably higher than Na requirements estimated by inevitable Na loss. Low dietary Na may therefore be a risk factor for maintaining positive balances of Ca and Mg.

Nishimuta M, Kodama N, Morikuni E, Yoshioka YH…
J. Nutr. Sci. Vitaminol. Aug 2005
PMID: 16261999

High Sodium has an Insignificant Effect on Bone Density in Rats

Abstract

Sodium and calcium intakes and bone mass in rats revisited.

High sodium intake accompanied by insufficient dietary calcium may have detrimental effects on bone mass. Our study evaluated the effects of increased sodium and decreased calcium intakes on bone mineral density (BMD) and bone mineral content (BMC) in rats.
Four-month-old female Wistar rats were given deionized water or 1.8% solution of sodium chloride in deionized water and fed normal (1.2%) or marginal (0.33%) calcium in the diet for 2 mo. At the end of the experiment, BMD and BMC of the whole body and urinary sodium and calcium excretion were evaluated. All rats were killed and right femurs were removed to assess dry and ash weights. Two-way analysis of variance was used to evaluate effect of salt intake and effect of dietary calcium on these parameters.
Salt-loaded animals had greater water consumption during the entire 2-mo period and significantly lower body weight from week 5 of the experiment. High salt intake increased urine volume and urinary excretion of sodium and calcium. Urinary calcium was about five times higher in salt-loaded animals than in rats on deionized water irrespective of dietary calcium content. Calcium in diet itself had no significant effect on these parameters. High salt intake slightly, but not significantly, decreased BMD, BMC, and femur weights. Lower calcium in diet significantly decreased BMD, and its effect on femur ash weight almost reached a level of significance.
We confirmed the benefit of adequate calcium intake to BMD. Under our experimental condition, high salt intake in rats for 2 mo had no statistically significant effect on femur weights, BMD, or BMC even with marginal calcium in the diet.

Sarić M, Piasek M, Blanusa M, Kostial K…
Nutrition May 2005
PMID: 15850968

DASH Diet and Sodium Reduction Improve Bone in Adults

Abstract

The DASH diet and sodium reduction improve markers of bone turnover and calcium metabolism in adults.

Dietary strategies to prevent and treat osteoporosis focus on increased intake of calcium and vitamin D. Modification of whole dietary patterns and sodium reduction may also be effective. We examined the effects of two dietary patterns and three sodium levels on bone and calcium metabolism in a randomized feeding study. A total of 186 adults, aged 23-76 y, participated. After a 2-wk run-in period, participants were assigned randomly to diets containing three levels of sodium (50, 100 and 150 mmol/d) to be consumed for 30 d in random order. Serum osteocalcin (OC), C-terminal telopeptide of type I collagen (CTX), fasting serum parathyroid hormone (PTH), urinary sodium, potassium, calcium and cAMP were measured at baseline and at the end of each sodium period. The Dietary Approaches to Stop Hypertension (DASH) diet reduced serum OC by 8-11% and CTX by 16-18% (both P < 0.001). Urinary calcium excretion did not differ between subjects that consumed the DASH and control diets. Reducing sodium from the high to the low level significantly decreased serum OC 0.6 microg/L in subjects that consumed the DASH diet, fasting serum PTH 2.66 ng/L in control subjects and urinary calcium 0.5 mmol/24 h in both groups. There were no consistent effects of the diets or sodium levels on urinary cAMP. In conclusion, the DASH diet significantly reduced bone turnover, which if sustained may improve bone mineral status. A reduced sodium intake reduced calcium excretion in both diet groups and serum OC in the DASH group. The DASH diet and reduced sodium intake may have complementary, beneficial effects on bone health.

Lin PH, Ginty F, Appel LJ, Aickin M…
J. Nutr. Oct 2003
PMID: 14519796 | Free Full Text

Low Sodium Causes Body to Rob Bones of Sodium, Calcium and Magnesium in Women

Abstract

Negative balance of calcium and magnesium under relatively low sodium intake in humans.

The balance of minerals (sodium [Na], potassium [K], calcium [Ca], and magnesium [Mg]) was measured in six female students for 10 d while under a relatively low Na intake (100 mmol/d or 2.2 g/d) with receiving adequate Ca (20 mmol/d or 800 mg/d) and Mg (12 mmol/d or 280 mg/d). Both the plasma renin activity (PRA) and aldosterone level were above the reference ranges throughout the experiment, which implied that the subjects were Na deficient. However, the urine Na excretion was about the same as that ingested, while there was no substantial reduction of sweat Na concentration observed during moderate physical exercise (13.2+/-2.6 mmol/L) (mean+/-SD). On the other hand, the urine Ca and Mg levels were high, but the apparent absorption of Ca and Mg was moderate (21 +/- 5%, 34 +/- 4%, respectively), which resulted in a negative balance of these two elements. It seems that the stored Na in the bone is eluted so as to compensate for the low dietary Na intake, while any excess Ca and Mg also inevitably flows into the blood stream with Na, which inhibited the intestinal absorption of both Ca and Mg and accelerates their excretion in urine.

Kodama N, Nishimuta M, Suzuki K
J. Nutr. Sci. Vitaminol. Jun 2003
PMID: 12953799

Review: Nutrients for Bone Health

Abstract

Essential Nutrients for Bone Health and a Review of their Availability in the Average North American Diet.

Osteoporosis and low bone mineral density affect millions of Americans. The majority of adults in North America have insufficient intake of vitamin D and calcium along with inadequate exercise. Physicians are aware that vitamin D, calcium and exercise are essential for maintenance of bone health. Physicians are less likely to be aware that dietary insufficiencies of magnesium, silicon, Vitamin K, and boron are also widely prevalent, and each of these essential nutrients is an important contributor to bone health. In addition, specific nutritional factors may improve calcium metabolism and bone formation. It is the authors’ opinion that nutritional supplements should attempt to provide ample, but not excessive, amounts of factors that are frequently insufficient in the typical American diet. In contrast to dietary insufficiencies, several nutrients that support bone health are readily available in the average American diet. These include zinc, manganese, and copper which may have adverse effects at higher levels of intake. Some multivitamins and bone support products provide additional quantities of nutrients that may be unnecessary or potentially harmful. The purpose of this paper is to identify specific nutritional components of bone health, the effects on bone, the level of availability in the average American diet, and the implications of supplementation for each nutritional component. A summary of recommended dietary supplementation is included.

Price CT, Langford JR, Liporace FA
Open Orthop J 2012
PMID: 22523525 | Free Full Text

Oral intake of 2 gm/day of strontium ranelate have improved bone strength and reduced fracture rates in women with osteoporosis, but there are reports of increased risks of venous blood clots and memory loss [82, 87].

Alcohol Reduces Bone Resorption Markers

Abstract

Moderate ingestion of alcohol is associated with acute ethanol-induced suppression of circulating CTX in a PTH-independent fashion.

The “J shape” curve linking the risk of poor bone health to alcohol intake is now well recognized from epidemiological studies. Ethanol and nonethanol components of alcoholic beverages could influence bone remodeling. However, in the absence of a solid underlying mechanism, the positive association between moderate alcoholic intake and BMD remains questionable because of confounding associated social factors. The objective of this work was to characterize the short-term effects of moderate alcohol consumption on circulating bone markers, especially those involved in bone resorption. Two sequential blood-sampling studies were undertaken in fasted healthy volunteers (age, 20-47 yr) over a 6-h period using beer of different alcohol levels (<0.05-4.6%), solutions of ethanol or orthosilicic acid (two major components of beer), and water +/- calcium chloride (positive and negative controls, respectively). Study 1 (24 subjects) assessed the effects of the different solutions, whereas study 2 (26 subjects) focused on ethanol/beer dose. Using all data in a “mixed effect model,” we identified the contributions of the individual components of beer, namely ethanol, energy, low-dose calcium, and high-dose orthosilicic acid, on acute bone resorption. Markers of bone formation were unchanged throughout the study for all solutions investigated. In contrast, the bone resorption marker, serum carboxy terminal telopeptide of type I collagen (CTX), was significantly reduced after ingestion of a 0.6 liters of ethanol solution (>2% ethanol; p <or= 0.01, RM-ANOVA), 0.6 liters of beer (<0.05-4.6% ethanol; p < 0.02), or a solution of calcium (180 mg calcium; p < 0.001), but only after calcium ingestion was the reduction in CTX preceded by a significant fall in serum PTH (p < 0.001). Orthosilicic acid had no acute effect. Similar reductions in CTX, from baseline, were measured in urine after ingestion of the test solutions; however, the biological variability in urine CTX was greater compared with serum CTX. Modeling indicated that the major, acute suppressive effects of moderate beer ingestion (0.6 liters) on CTX were caused by energy intake in the early phase (approximately 0-3 h) and a “nonenergy” ethanol component in the later phase (approximately 3 to >6 h). The early effect on bone resorption is well described after the intake of energy, mediated by glucagon-like peptide-2, but the late effect of moderate alcohol ingestion is novel, seems to be ethanol specific, and is mediated in a non-calcitonin- and a non-PTH-dependent fashion, thus providing a mechanism for the positive association between moderate alcohol ingestion and BMD.

Sripanyakorn S, Jugdaohsingh R, Mander A, Davidson SL…
J. Bone Miner. Res. Aug 2009
PMID: 19257829 | Free Full Text

Silicon as Orthosilicic Acid Decreases Osteoblast Survivability In Vitro

Abstract

Divergent effects of orthosilicic acid and dimethylsilanediol on cell survival and adhesion in human osteoblast-like cells.

Although dietary silicon (Si) is recognized to be an important factor for the growth and development of bone and connective tissue, its biochemical role has yet to be identified. The predominant Si-containing species in blood and other biofluids is orthosilicic acid, Si(OH)(4). Dimethylsilanediol, (CH(3))(2)Si(OH)(2), is an environmental contaminant that results from decomposition of silicone compounds used in personal hygiene, health care and industrial products. We examined the in vitro effects of both Si species on the survival (colony forming efficiency), proliferation (DNA content), differentiation (alkaline phosphatase activity) and adhesion (relative protein content) of the human osteoblast-like cell lines Saos-2 and hFOB 1.19. Orthosilicic acid yielded a small, dose-dependent decrease in Saos-2 cell survivability up to its 1,700 micromol/L solubility limit, by which point survival was 20% less than that of untreated cells. This negative association, although small, correlated with a reduction in the proliferation and adhesion of Saos-2 cells as well as of hFOB 1.19 and osteoclast-like GCT cells. By contrast, dimethylsilanediol treatment had no discernable influence on Saos-2 survivability at concentrations up to 50 micromol/L, and yet significantly enhanced cell survival at higher doses. Moreover, dimethylsilanediol did not affect proliferation or adhesion of any cell line. The findings show that orthosilicic acid and dimethylsilanediol affect osteoblast-like cells very differently, providing insight into the mechanism by which silicon influences bone health, although the specific site of Si activity remains unknown. There was no evidence to suggest that dimethylsilanediol is cytotoxic at environmental/physiological concentrations.

Duivenvoorden WC, Middleton A, Kinrade SD
J Trace Elem Med Biol 2008
PMID: 18755397

Silicon Antagonizes Calcium and Magnesium in Animals

Abstract

Effects of high levels of dietary silicon on bone development of growing rats and turkeys fed semi-purified diets.

Two experiments were conducted using a completely randomized design to study the effects of high levels of silicon (Si) supplementation on bone development, structure, and strength in growing rats and turkeys. Rats were supplemented at two dietary Si levels: 0 and 500 ppm; and the turkeys were supplemented at four dietary Si levels: 0, 135, 270, and 540 ppm in semi-purified diets of dextrose-albumin for rats and dextrose-casein for turkeys. The experiments lasted 8 and 4 weeks for the rats and turkeys, respectively. Physical, mechanical, and chemical parameters of bones were measured. All the physical and mechanical measures of bone size and strength were not different (P > 0.05) between treatments in rats and turkeys except the moment of inertia, which was lower (P < 0.01) in rats on the 500 ppm Si level of supplementation. There were small but consistent reductions in structural and strength parameters with Si supplementation which were not wholly due to differences in bodyweights of the rats and turkeys. Although bone mineral composition was not affected (P > 0.05) by Si supplementation, plasma magnesium (P = 0.08) in rats and plasma calcium (P < 0.05) in turkeys were reduced by high levels of Si supplementation. The antagonistic relations of high Si levels with calcium and magnesium were deemed to be the mechanisms through which high Si imposes its deleterious effects on bone size and strength.

Kayongo-Male H, Julson JL
Biol Trace Elem Res 2008
PMID: 18418557