Mineral water as a source of dietary calcium: acute effects on parathyroid function and bone resorption in young men

Supplementing Low-Sodium Bicarbonate-Calcic (Lete)® Water: Effects in Women on Bone and Systemic Metabolism

Calcium (Ca) represents about 40% of the total mineral mass, mainly in the bone, providing mechanical strength to the skeleton and teeth. An adequate Ca intake is necessary for bone growth and development in children and adolescents and for maintaining bone mineral loss in elderly age. Ca deficiency predisposes to osteopenia and osteoporosis. Healthy nutrition, including an adequate intake of Ca-rich food, is paramount to prevent and cure osteoporosis. Recently, several clinical studies have demonstrated that, in conditions of Ca dysmetabolism, Ca-rich mineral water is beneficial as a valuable source of Ca to be used as an alternative to caloric Ca-rich dairy products. Although promising, these data have been collected from small groups of participants. Moreover, they mainly regard the effect of Ca-rich mineral water on bone metabolism. In contrast, an investigation of the effect of Ca supplementation on systemic metabolism is needed to address the spreading of systemic metabolic dysfunction often associated with Ca dysmetabolism. In the present study, we analyzed urine and blood sera of 120 women in perimenopausal condition who were subjected for six months to 2l daily consumption of bicarbonate-calcium mineral water marketed under ®Lete. Remarkably, this water, in addition to being rich in calcium and bicarbonate, is also low in sodium. A complete set of laboratory tests was carried out to investigate whether the specific water composition was such to confirm the known therapeutic effects on bone metabolism. Second, but not least, urine and blood sera were analyzed using NMR-based metabolomic procedures to investigate, other than the action on Ca metabolism, potential system-wide metabolic effects. Our data show that Lete water is a valid supplement for compensating for Ca dysmetabolism and preserving bone health and integrity.

Including calcium-fortified water or flour in modeled diets based on local foods could improve calcium intake for women, adolescent girls, and young children in Bangladesh, Uganda, and Guatemala

Adequate calcium intake is essential for health, especially for infants, children, adolescents, and women, yet is difficult to achieve with local foods in many low- and middle-income countries. Previous analysis found it was not always possible to identify food-based recommendations (FBRs) that reached the calcium population recommended intake (PRI) for these groups in Bangladesh, Guatemala, and Uganda. We have modeled the potential contribution of calcium-fortified drinking water or wheat flour to FBR sets, to fill the remaining intake gaps. Optimized diets containing fortified products, with calcium-rich local foods, achieved the calcium PRI for all target groups. Combining fortified water or flour with FBRs met dietary intake targets for adolescent girls in all geographies and allowed a reduction from 3-4 to the more feasible 1-2 FBRs. Water with a calcium concentration of 100 mg/L with FBRs was sufficient to meet calcium targets in Uganda, but higher concentrations (400-500 mg/L) were mostly required in Guatemala and Bangladesh. Combining calcium-fortified wheat flour at 400 mg/100 g of flour and the FBR for small fish resulted in diets meeting the calcium PRI in Bangladesh. Calcium-fortified water or flour could improve calcium intake for vulnerable populations, especially when combined with FBRs based on locally available foods.

Exploring the Potential Benefits of Natural Calcium-Rich Mineral Waters for Health and Wellness: A Systematic Review

This systematic review investigates the potential health and wellness benefits of natural calcium-rich mineral waters. It emphasizes the importance of dietary calcium sourced from natural mineral waters in promoting bone health, maintaining cardiovascular function, aiding in weight management, and enhancing overall well-being. The review process involved the comprehensive analysis of peer-reviewed articles, clinical trials, and experimental studies published within the last decade. Findings reveal that consuming calcium-rich mineral water can contribute significantly to daily calcium intake, particularly for those with lactose intolerance or individuals adhering to plant-based diets. The unique bioavailability of calcium from such waters also appears to enhance absorption, thus potentially offering an advantage over other calcium sources. The potential benefits extend to the cardiovascular system, with some studies indicating a reduction in blood pressure and the prevalence of cardiovascular diseases. Emerging evidence suggests that calcium-rich mineral water might have a role in body weight management, though further research is needed. The review identifies several areas requiring additional research, such as the potential interaction between calcium-rich mineral water and other dietary components, the effects on populations with specific health conditions, and the long-term effects of consumption. In conclusion, natural calcium-rich mineral waters show promise as a readily accessible and bioavailable sources of dietary calcium, potentially beneficial for a broad range of individuals. However, further investigation is required to fully understand its range of health impacts and define optimal intake levels.

Drinking Natural Mineral Water Maintains Bone Health in Young Rats With Metabolic Acidosis

Introduction

Metabolic acidosis affects bone health. It remains unclear whether drinking natural mineral water is better for maintaining bone health in the youth with metabolic acidosis.

Materials and Methods

Sixty young female rats (3-weeks-old) were randomly divided into three groups and drank purified water (PW, as control), bicarbonate-rich natural mineral water (Bic-NMW), or sulfate-rich natural mineral water (Sul-NMW), which, respectively, contained calcium (0.17, 155, and 175 mg/L), bicarbonate (0.1360, and 139 mg/L) and sulfate (0, 35.6, and 532 mg/L), for 16 weeks. In the last 3 weeks, metabolic acidosis was induced in 10 rats per group by adding NH₄Cl (0.28 mM) to drinking water. The rats' blood, urine, and femur were collected for assessing acid-base status, calcium metabolism, bone microstructure, and strength. The difference between the three groups was determined using one-way ANOVA followed by the Student–Newman–Keuls test or Dunnett's T3 test.

Results

Compared with the PW rats, the Bic-NMW rats and the Sul-NMW rats had less urine net acid excretion (−1.51, 0.20 vs. 10.77, EQ/L), higher bone mineral density (442.50, 407.49 vs. 373.28, mg/mm³), growth cartilage width (271.83, 283.83 vs. 233.27, μm) and cortical trabecular area (9.33, 9.55 vs. 5.05, mm²), and smaller cortical marrow cavity area (5.40, 5.49 vs. 7.27, mm²) in the femur (P < 0.05). Besides, the Bic-NMW rats had less serum calcium (2.53 vs. 2.68, mmol/L) and C-terminal cross-linked telopeptide of type-I collagen (1.35 vs. 1.93, ng/mL), and higher serum calcitonin (0.61 vs. 0.39, μg/L), femoral trabecular thickness (0.10 vs. 0.09, μm), bone volume/total volume (0.42 vs. 0.34, %), cortical bone area (15.91 vs. 12.80, mm²), and ultimate stress (35.12 vs. 29.32, MPa) (P < 0.05). The Sul-NMW rats had more osteoclasts (22.50 vs. 11.54, cells/field) (P < 0.05).

Conclusions

Drinking natural mineral water, especially bicarbonate-rich natural mineral water, is effective in improving bone health in young rats with metabolic acidosis. These benefits include maintaining bone mineral density, and improving bone microstructure and biomechanical properties via moderating metabolic acidosis.

Acute CTX-1 Suppression With Milk Calcium or Calcium Carbonate is Independent of Visceral Fat in A Randomized Crossover Study in Lean and Overweight Postmenopausal Women

BACKGROUND

Postmenopausal women with higher visceral adipose tissue (VAT) present with suppressed bone resorption (lower c-terminal cross-linking telopeptide of type I collagen, CTX-1) and turnover (lower osteocalcin) but whether this blunts the effect of calcium is unknown.

OBJECTIVE

The primary outcome of this study was the effect of VAT on changes in CTX-1 after intake of two forms of calcium. Secondary outcomes included changes in parathyroid hormone (PTH), serum calcium, phosphorus, and alkaline phosphatase (ALP).

DESIGN

Randomized open three period crossover trial conducted between 2017-2019 at the University of South Australia among 77 lean and overweight postmenopausal women (53-79 y) with body mass index (BMI) less than 25 kg/m2 and greater than 27 kg/m2, respectively. Participants received a single dose of milk (1000 mg calcium), calcium carbonate tablet (1000 mg calcium), and fruit juice (no calcium) in random order with a seven-day washout period. Blood samples were collected at baseline and hourly for 5h. Data was analysed by repeated measures analysis of variance (ANOVA) of log-transformed data.

RESULTS

At baseline, women with higher VAT had significantly lower CTX-1 and higher PTH (44% lower and 30% higher, respectively between Q4 and Q1, P < 0.0001). VAT had no influence on the acute changes in CTX-1 or PTH with calcium or juice. A suppression of 44% in CTX-1 was seen with calcium carbonate and milk and a suppression of 18% with juice. PTH was suppressed more with calcium carbonate (47%) compared to milk (22%). Milk calcium reduced PTH and CTX-1 at 2-hour while calcium carbonate reduced PTH in 1 hour. The suppression in CTX-1 was slower with lowest levels at 4-5 hour.

CONCLUSIONS

1000 mg calcium obtained from milk or from calcium carbonate is effective in acutely suppressing bone resorption in postmenopausal women irrespective of visceral fat.This trial is registered with the Australian New Zealand Clinical Trials Registry http://www.ANZCTR.org.au/ACTRN12617000779370.aspx (ACTRN 12617000779370).

Impact of water fortification with calcium on calcium intake in different countries: a simulation study

Objective:

To simulate the impact – effectiveness and safety – of water fortification with different concentrations of Ca using the Intake Modelling, Assessment and Planning Program.

Design:

This is a secondary analysis of national or sub-national dietary intake databases.

Setting and Participants:

Uganda, Lao People’s Democratic Republic (PDR), Bangladesh, Zambia, Argentina, USA and Italy.

Results:

We found that for dietary databases assessed from low- and middle-income countries (LMIC), the strategy of fortifying water with 500 mg of Ca/l would decrease the prevalence of low Ca intake in all age groups. We also found that this strategy would be safe as no group would present a percentage of individuals exceeding the upper limit in >2 %, except women aged 19–31 years in Lao PDR, where 6·6 % of women in this group would exceed the upper limit of Ca intake. The same strategy would lead to some groups exceeding the upper limit in USA and Italy.

Conclusions:

We found that for most LMIC countries, water fortified with Ca could decrease the prevalence of Ca intake inadequacy without exceeding the upper levels of Ca intake.

Differential Modulation of Cancellous and Cortical Distal Femur by Fructose and Natural Mineral-Rich Water Consumption in Ovariectomized Female Sprague Dawley Rats

Bone mineral density (BMD) and microstructure depend on estrogens and diet. We assessed the impact of natural mineral-rich water ingestion on distal femur of fructose-fed estrogen-deficient female Sprague Dawley rats. Ovariectomized rats drank tap or mineral-rich waters, with or without 10%-fructose, for 10 weeks. A sham-operated group drinking tap water was included (n = 6/group). Cancellous and cortical bone compartments were analyzed by microcomputed tomography. Circulating bone metabolism markers were measured by enzyme immunoassay/enzyme-linked immunosorbent assay or multiplex bead assay. Ovariectomy significantly worsened cancellous but not cortical bone, significantly increased circulating degradation products from C-terminal telopeptides of type I collagen and receptor activator of nuclear factor-kappaB ligand (RANKL), and significantly decreased circulating osteoprotegerin and osteoprotegerin/RANKL ratio. In ovariectomized rats, in cancellous bone, significant water effect was observed for all microstructural properties, except for the degree of anisotropy, and BMD (neither a significant fructose effect nor a significant interaction between water and fructose ingestion effects were observed). In cortical bone, it was observed a significant (a) water effect for medullary volume and cortical endosteal perimeter; (b) fructose effect for cortical thickness, medullary volume, cross-sectional thickness and cortical endosteal and periosteal perimeters; and (c) interaction effect for mean eccentricity. In blood, significant fructose and interaction effects were found for osteoprotegerin (no significant water effect was seen). For the first time in ovariectomized rats, the positive modulation of cortical but not of cancellous bone by fructose ingestion and of both bone locations by natural mineral-rich water ingestion is described.

Calcium Intake in Bone Health: A Focus on Calcium-Rich Mineral Waters

Calcium is an essential element that plays numerous biological functions in the human body, of which one of the most important is skeleton mineralization. Bone is a mineralized connective tissue in which calcium represents the major component, conferring bone strength and structure. Proper dietary calcium intake is important for bone development and metabolism, and its requirement can vary throughout life. The mineral composition of drinking water is becoming relevant in the modulation of calcium homeostasis. In fact, calcium present in mineral drinking waters is an important quantitative source of calcium intake. This, together with its excellent bioavailability, contributes to the maintenance of the bone health. This article aims to examine studies that assessed the bioavailability of the calcium contained in calcium-rich mineral waters and their impact on bone health, including original data collected in a recent study in humans.

Low-mineral direct drinking water in school may retard height growth and increase dental caries in schoolchildren in China

Although direct drinking water (DDW) systems that utilize a reverse-osmosis technique are thought to be harmful to children's development by reducing their daily mineral intake, few population data are available regarding this topic. We conducted an eco-epidemiological study to investigate the influence of low-mineral DDW on the development of schoolchildren. We collected developmental parameters of 13,723 girls and 16,161 boys before and after the introduction of DDW systems in 25 schools and measured the mineral levels in the DDW of each school. The DDW in 22 schools had lower-than-recommended levels of magnesium and calcium (magnesium, 10 mg/L and calcium, 20 mg/L, WHO). We found that children exposed to low-mineral DDW exhibited reduced height and diminished height increases as well as higher prevalences and incidences of hypoevolutism and dental caries (p < 0.01). This exposure was a risk factor for a greater incidence of both hypoevolutism and dental caries in children (RR = 7.110 (1.688, 29.953) and 1.813 (1.309, 2.509), respectively; p < 0.01). Our results suggest that low-mineral DDW may retard height growth and promote the incidence of dental caries in schoolchildren; thus, schools should choose DDW treatment systems that retain the minerals in water.

Calcium Bioavailability from Mineral Waters with Different Mineralization in Comparison to Milk and a Supplement

OBJECTIVE

The aim of the present study was to compare the bioavailability of calcium from 3 mineral waters with different concentrations of minerals with that of milk and a calcium supplement.

METHODS

A single-center, randomized controlled trial with a crossover design with 21 healthy men and women was conducted at the Institute of Food Science and Human Nutrition, Leibniz University Hannover. The participants consumed the 5 test products providing 300 mg of calcium each on 5 examination days with 1-week wash-out phases in between. Primary outcome variables were the area under the curve of serum calcium levels for 10-hour (AUC_0-10h) and 24-hour urinary calcium excretion.

RESULTS

In all groups, no significant differences in the AUC_0-10h of serum calcium levels as well as in the 24-hour urinary calcium excretion were observed. Likewise, mean changes in serum phosphate and urinary phosphate, as well as serum parathormone, showed no differences between the groups.

CONCLUSION

Given an equivalent bioavailability of calcium in all test products, neither a high concentration of SO₄^2- or of HCO₃ influenced the bioavailability of calcium. Accordingly, the use of mineral water with high concentrations of calcium constitutes a calorie-free calcium source that can improve calcium supply.

Population data on calcium in drinking water and hip fracture: An association may depend on other minerals in water. A NOREPOS study

BACKGROUND

The Norwegian population has among the highest hip fracture rates in the world. The incidence varies geographically, also within Norway. Calcium in drinking water has been found to be beneficially associated with bone health in some studies, but not in all. In most previous studies, other minerals in water have not been taken into account. Trace minerals, for which drinking water can be an important source and even fulfill the daily nutritional requirement, could act as effect-modifiers in the association between calcium and hip fracture risk. The aim of the present study was to investigate the association between calcium in drinking water and hip fracture, and whether other water minerals modified this association.

MATERIALS AND METHODS

A survey of trace metals in 429 waterworks, supplying 64% of the population in Norway, was linked geographically to the home addresses of patients with incident hip fractures (1994-2000). Drinking water mineral concentrations were divided into "low" (below and equal waterworks average) and "high" (above waterworks average). Poisson regression models were fitted, and all incidence rate ratios (IRRs) were adjusted for age, geographic region, urbanization degree, type of water source, and pH of the water. Effect modifications were examined by stratification, and interactions between calcium and magnesium, copper, zinc, iron and manganese were tested both on the multiplicative and the additive scale. Analyses were stratified on gender.

RESULTS

Among those supplied from the 429 waterworks (2,110,916 person-years in men and 2,397,217 person-years in women), 5433 men and 13,493 women aged 50-85 years suffered a hip fracture during 1994-2000. Compared to low calcium in drinking water, a high level was associated with a 15% lower hip fracture risk in men (IRR=0.85, 95% CI: 0.78, 0.91) but no significant difference was found in women (IRR=0.98, 95%CI: 0.93-1.02). There was interaction between calcium and copper on hip fracture risk in men (p=0.051); the association between calcium and hip fracture risk was stronger when the copper concentration in water was high (IRR=0.52, 95% CI: 0.35, 0.78) as opposed to when it was low (IRR=0.88, 95% CI: 0.81, 0.94). This pattern persisted also after including potential confounding factors and other minerals in the model. No similar variation in risk was found in women.

CONCLUSION

In this large, prospective population study covering two thirds of the Norwegian population and comprising 19,000 hip fractures, we found an inverse association between calcium in drinking water and hip fracture risk in men. The association was stronger when the copper concentration in the water was high.

Calcium revisited, part III: effect of dietary calcium on BMD and fracture risk

Food can be an excellent source of calcium. Dietary calcium is in general as well absorbed as calcium supplements, and exerts the same effects on bone. The main sources are dairy products, but also some vegetables and fruits contain considerable amounts of calcium. Mineral water can serve as a supplement. Cross-sectional, longitudinal and some interventional trials have shown positive effects on bone metabolism, bone density and bone loss. But the effect on fracture incidence is less certain, and that of milk, the most studied dairy product, still unproven.

Physiological basis of dietary prevention of perimenopausal disorders in the context of dietary habits associated with the consumption of water and beverages by women aged 45-65

INTRODUCTION

This study aimed to evaluate the amount of water and type of beverages consumed by women of perimenopausal age against a background of dietary prevention of perimenopausal disorders.

MATERIAL AND METHODS

This study was conducted in autumn 2012, in Wielkopolska Province (Poland), on 100 women aged from 45 to 65 years, employed as office workers. Information on the diet, beverages consumption and anthropometric data were collected.

RESULTS

Analysis of the nutritional status of the surveyed women showed that over 50% of them had excess body weight. Analysis of the survey results indicated that the amount of water in the diet of the examined women was appropriate, although the type of drinks consumed was inadequate. The women consumed too much coffee and tea, and simultaneously had a low intake of potable water. More than a half of the surveyed women sweetened coffee and tea. Women with excess body weight did so statistically significantly quite often, and they also used larger amounts of sugar for sweetening. Nearly 60% of the surveyed women added milk, or less frequently cream, to coffee. Milk was statistically significantly more frequently chosen by women with normal body weight, and cream by women with excess body weight. There was a positive correlation between body mass index and the energy value of the consumed fluids.

CONCLUSIONS

The dietary irregularities identified in this study may intensify perimenopausal symptoms and contribute to the development of diet-related chronic diseases. Taking into account the observed irregularities, it seems appropriate to provide perimenopausal women with nutrition education and diet correction, including the amount and type of fluids consumed.

Nationwide data on municipal drinking water and hip fracture: could calcium and magnesium be protective? A NOREPOS study

Norway has a high incidence of hip fractures, and the incidence varies by degree of urbanization. This variation may reflect a difference in underlying environmental factors, perhaps variations in the concentration of calcium and magnesium in municipal drinking water. A trace metal survey (1986-1991) in 556 waterworks (supplying 64% of the Norwegian population) was linked geographically to hip fractures from hospitals throughout the country (1994-2000). In all, 5472 men and 13,604 women aged 50-85years suffered a hip fracture. Poisson regression models were fitted, adjusting for age, urbanization degree, region of residence, type of water source, and pH. The concentrations of calcium and magnesium in drinking water were generally low. An inverse association was found between concentration of magnesium and risk of hip fracture in both genders (IRR men highest vs. lowest tertile=0.80, 95% CI: 0.74, 0.87; IRR women highest vs. lowest tertile=0.90, 95% CI: 0.85, 0.95), but no consistent association between calcium and hip fracture risk was observed. The highest tertile of urbanization degree (city), compared to the lowest (rural), was related to a 23 and 24% increase in hip fracture risk in men and women, respectively. The association between magnesium and hip fracture did not explain the variation in hip fracture risk between city and rural areas. Magnesium in drinking water may have a protective role against hip fractures; however this association should be further investigated.

Calcium revisited: part I

In February 2013, the US Preventive Services Task Force (see www.uspreventiveservicestaskforce.org) recommended 'against daily supplementation with 400 IU or less of vitamin D3 and 1000, mg or less of calcium for the primary prevention of fractures in non institutionalized postmenopausal women', which illustrates the divergence of opinions. This review wants to shed an objective light on the importance of calcium for bone health. It cannot compete with an exhaustive analysis of the literature by an institute. It does not mention all significant references. But it highlights some pivotal studies from the past and it refers to recent studies that opened new views or added essential data to known facts. It also reflects the personal perception of the author. The first part deals mainly with intake, absorption, needs and recommendations; the second part will discuss the effects of calcium and its supplements on bone.

Effect of fasting versus feeding on the bone metabolic response to running

Individuals often perform exercise in the fasted state, but the effects on bone metabolism are not currently known. We compared the effect of an overnight fast with feeding a mixed meal on the bone metabolic response to treadmill running. Ten, physically-active males aged 28 ± 4y (mean ±SD) completed two, counterbalanced, 8d trials. After 3d on a standardised diet, participants performed 60 min of treadmill running at 65% VO(2max) on Day 4 following an overnight fast (FAST) or a standardised breakfast (FED). Blood samples were collected at baseline, before and during exercise, for 3h after exercise, and on four consecutive follow-up days (FU1-FU4). Plasma/serum were analysed for the c-terminal telopeptide region of collagen type 1 (β-CTX), n-terminal propeptides of procollagen type 1 (P1NP), osteocalcin (OC), bone alkaline phosphatase (bone ALP), parathyroid hormone (PTH), albumin-adjusted calcium, phosphate, osteoprotegerin (OPG), cortisol, leptin and ghrelin. Only the β-CTX response was significantly affected by feeding. Pre-exercise concentrations decreased more in FED compared with FAST (47% vs 26%, P<0.001) but increased during exercise in both groups and were not significantly different from baseline at 1h post-exercise. At 3h post-exercise, concentrations were decreased (33%, P<0.001) from baseline in FAST and significantly lower (P<0.001) than in FED. P1NP and PTH increased, and OC decreased during exercise. Bone markers were not significantly different from baseline on FU1-FU4. Fasting had only a minor effect on the bone metabolic response to subsequent acute, endurance exercise, reducing the duration of the increase in β-CTX during early recovery, but having no effect on changes in bone formation markers. The reduced duration of the β-CTX response with fasting was not fully explained by changes in PTH, OPG, leptin or ghrelin.

Postprandial bone turnover is independent of calories above 250 kcal

Background

The mechanisms causing bone turnover after food intake have not yet been elucidated. Several gut hormones are secreted in the postprandial phase, proportional to meal calorie content, and possibly one or more of these could influence bone turnover. The aim of this study was to investigate bone turnover in proportion to graded-calorie and fixed calcium containing meals.

Methods

A group of healthy volunteers were given six meals with calories varying from 250 to 3000 kcal on different occasions. All the meals contained 500 mg of calcium. C-telopeptide type I collagen (CTX) was measured before and 180 min after each meal.

Results

All meals significantly reduced CTX between 35.8 ± 5.6% and 44.8 ± 3.8%. No significant difference in CTX was however apparent for the different calorie containing meals. Observed differences suggest a trend to greater CTX suppression with lower protein and higher fat content of meals.

Conclusion

Changes in CTX are not proportional to calorie contents when the meals contain 500 mg of calcium. Further studies should now determine whether patients with increased bone resorption would benefit from multiple small meals to slow down the rate of bone loss.

[Health-related effects of natural mineral waters]

The medical importance of mineral waters depends on the contained amount of minerals and trace elements. Calcium and magnesium in mineral waters are of greatest interest with respect to their potential relevance for the health status; iodine, fluorine and lithium are the most important trace elements. The bioavailability of minerals from mineral water is good and can be compared with the values derived from milk. A positive effect of the minerals in mineral water on health status is especially apparent in the case of insufficient intake by nutrition. The apprehension that there might be an undesired hypertensinogenic effect due to the sodium content in mineral waters is not justified. Sodium is present in mineral water in small amounts only, and mainly as sodium bicarbonate, which has no effect on blood pressure. A certain advantage of a delivery of minerals and trace elements by regular drinking of mineral waters is the simultaneous intake of water, without supply of energy. Studies giving direct evidence of the health value of a regular consumption of mineral waters are, however, up to now rather scarce.

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.

Alkaline mineral water lowers bone resorption even in calcium sufficiency: alkaline mineral water and bone metabolism

BACKGROUND

Dietary acid charge enhances bone loss. Bicarbonate or alkali diet decreases bone resorption in humans. We compared the effect of an alkaline mineral water, rich in bicarbonate, with that of an acid one, rich in calcium only, on bone markers, in young women with a normal calcium intake.

METHODS

This study compared water A (per litre: 520 mg Ca, 291 mg HCO(3)(-), 1160 mg SO(4)(-), Potential Renal Acid load (PRAL) +9.2 mEq) with water B (per litre: 547 mg Ca, 2172 mg HCO(3)(-), 9 mg SO(4)(-), PRAL -11.2 mEq). 30 female dieticians aged 26.3 yrs (SD 7.3) were randomized into two groups, followed an identical weighed, balanced diet (965 mg Ca) and drank 1.5 l/d of the assigned water. Changes in blood and urine electrolytes, C-telopeptides (CTX), urinary pH and bicarbonate, and serum PTH were measured after 2 and 4 weeks.

RESULTS

The two groups were not different at baseline, and showed a similar increase in urinary calcium excretion. Urinary pH and bicarbonate excretion increased with water B, but not with water A. PTH (p=0.022) and S-CTX (p=0.023) decreased with water B but not with water A.

CONCLUSION

In calcium sufficiency, the acid calcium-rich water had no effect on bone resorption, while the alkaline water rich in bicarbonate led to a significant decrease of PTH and of S-CTX.

The composition of mineral waters sourced from Europe and North America in respect to bone health: composition of mineral water optimal for bone

The consumption of mineral waters is increasing in industrialised countries. High intakes of Ca and other alkalising cations as well as a low acid intake are beneficial to bone. We examined which components of mineral waters are conditioning their Ca content and their alkalinising power, in order to define the optimal profile. European mineral waters were randomly selected on the Internet: 100 waters with less than 200 mg Ca/l (9.98 mEq/l) and fifty with more than 200 mg/l, all with complete data for SO4, P, Cl, Na, K, Mg and Ca, and most also for HCO3. For comparison, forty North American mineral waters were randomly chosen. The potential renal acid load (PRAL) was calculated for each mineral water. North American waters did not reveal significant results because of their low mineralisation. We performed correlations between all eight components in order to explore the properties of the mineral waters. In the European waters, twenty-six out of twenty-eight correlations showed a P value of <or= 0.01. In waters with PRAL >0 (acidifying waters), PRAL was positively correlated with SO4, Ca, K and Mg (P < 0.001). In those with PRAL < 0 (alkalinising waters), PRAL was negatively correlated with HCO3, Na, Mg, Ca, K, Cl and SO4 (P < 0.001). SO4 and HCO3 were not found together in high quantities in the same water for geochemical reasons. A high Ca content is associated with either a high SO4 or a high HCO3 content. SO4 theoretically increases Ca excretion, while HCO3 and low PRAL values are associated with positive effects on bone. Therefore, the best waters for bone health are rich in both HCO3 and Ca, and by consequence low in SO4.

The effect of the alkali load of mineral water on bone metabolism: interventional studies

Alkali supplements decrease bone resorption and increase bone mineral density. Alkali diets also lower bone resorption. Mineral waters alone could have such an effect. In several subsequent studies in humans, bicarbonate-rich alkali mineral waters with low potential renal acid load values were shown to decrease bone resorption markers and even parathyroid hormone levels. This effect seems to be stronger than that of acidic calcium-rich mineral waters and could also be demonstrated in calcium sufficiency.

Bone remodelling is not affected by consumption of a sodium-rich carbonated mineral water in healthy postmenopausal women

This study was designed to investigate the possible effects of consuming Na-rich carbonated mineral water on bone remodelling and urinary mineral excretion in postmenopausal women. Women (n18) included were amenorrhoeic (>1 year), healthy and not obese (BMI <30 kg/m2). No woman was taking oestrogen replacement therapy, mineral and vitamin supplements, phyto-oestrogens or medications known to affect bone and lipid metabolism. In two consecutive interventions that lasted 8 weeks each, women drank 1 litre of control mineral water daily and 1 litre of carbonated mineral water, rich in Na, HCO–3inf super and Cl−, daily. Body weight and height were measured, BMI was calculated and blood pressure was measured. Blood samples were taken from fasting subjects and serum obtained to analyse the biochemical bone markers, procollagen I amino-terminal propeptide (PINP) and β-carboxy-terminal telopeptide of collagen (β-CTX). At the end of each period, 24 h urine samples were collected to determine Ca, Mg, P, Na+, K+, Cl−, urine excretion and urinary pH. No changes in body weight, BMI or blood pressure were observed during the experimental period. Ca excretion was lower after the intake of carbonated water than after intake of the control water (P=0·037) while P excretion was higher (P=0·015). Total urine, Na and Cl−excretion did not differ between the two periods but urinary pH was increased after the intake of carbonated mineral water. PINP and β-CTX did not differ between the two periods. Daily consumption of 1 litre of Na-rich carbonated mineral water for 8 weeks does not affect bone remodelling in healthy postmenopausal women.

Moderate alcohol consumption and increased bone mineral density: potential ethanol and non-ethanol mechanisms

Mounting epidemiological evidence indicates an association between the moderate ingestion of alcoholic beverages and higher bone mineral density (v. abstainers). More limited findings provide some evidence for translation of this association into reduced fracture risk, but further studies are required. Here, these data are reviewed and caveats in their assimilation, comparison and interpretation as well as in the use and application of bone health indices are discussed. Whilst it is concluded that evidence is now strong for the moderate alcohol-bone health association, at least in relation to bone mineral density, mechanisms are less clear. Both ethanol and non-ethanol components have been implicated as factors that positively affect bone health in the light of moderate consumption of alcoholic beverages, and four particular areas are discussed. First, recent findings suggest that moderate ethanol consumption acutely inhibits bone resorption, in a non-parathyroid hormone- and non-calcitonin-dependent fashion, which can only partly be attributed to an energy effect. Second, critical review of the literature does not support a role for moderate ethanol consumption affecting oestrogen status and leading to a knock-on effect on bone. Third, Si is present at high levels in certain alcoholic beverages, especially beer, and may have a measurable role in promoting bone formation. Fourth, a large body of work indicates that phytochemicals (e.g. polyphenols) from alcoholic beverages could influence bone health, but human data are lacking. With further work it is hoped to be able to model epidemiological observations and provide a clear pathway between the magnitude of association and the relative contribution of these mechanisms for the major classes of alcoholic beverage.

Sodium bicarbonated mineral water decreases postprandial lipaemia in postmenopausal women compared to a low mineral water

The role of bicarbonated mineral waters on lipid metabolism and lipoprotein concentrations in man has scarcely been investigated. The present study aimed to investigate whether drinking sodium bicarbonated mineral water affects postprandial cholesterol and triacylglycerol metabolism in postmenopausal women. In a three-way, randomised, crossover study, eighteen healthy postmenopausal women consumed two sodium bicarbonated mineral waters (bicarbonated mineral water 1 and bicarbonated mineral water 2) and a low mineral water (500 ml of each) with a standard fat-rich meal (4552 kJ; 75.3 g fat). The bicarbonated waters were rich in sodium and bicarbonate and bicarbonated mineral water 1 contained 5.7 times more fluoride than bicarbonated mineral water 2. Fasting blood samples and postprandial blood samples were taken at 30, 60, 120, 240, 360 and 420 min after the end of the meal consumption. Cholesterol and triacylglycerols were determined in serum and chylomicrons. A significant water consumption effect was observed in the total area under the curve (TAUC) of serum and chylomicron triacylglycerols (ANOVA, P=0.008 and P=0.027, respectively). TAUC of serum triacylglycerols for bicarbonated mineral water 2 was significantly lower compared to low mineral water (Bonferroni, P=0.039). Peak concentration of serum triacylglycerols showed a significant water effect (P=0.025). Changes in chylomicron cholesterol were not significantly affected by the type of water. Bicarbonated mineral waters 1 and 2 did not show any significant differences. Drinking sodium bicarbonate-rich mineral waters reduces postprandial lipaemia in healthy postmenopausal women compared to drinking a low mineral water.

Consumption of a high calcium mineral water lowers biochemical indices of bone remodeling in postmenopausal women with low calcium intake

Many postmenopausal women have a calcium intake far below the recommended amount and, in addition to attempting to improve their diet, need a calcium supplement. The aim of the study was to assess the effects of the consumption of a high calcium mineral water (HCaMW) on biochemical indices of bone remodeling in postmenopausal women with low Ca intake. A 6-month randomized double-blind placebo-controlled trial was designed to assess the effects of a daily consumption of 1 liter of a HCaMW (596 mg Ca/l) on serum parathyroid hormone (PTH) and biochemical markers of bone remodeling in postmenopausal women with a dietary Ca intake lower than 700 mg/day. The placebo group drank 1 liter of a mineral water with a low calcium content (10 mg/l). One hundred eighty healthy women were recruited (mean age: 70.1+/-4.0 years); 152 completed the 6-month trial. The changes from baseline of biochemical indices after 6 months consisted of a significant 14.1% decrease of serum PTH, osteocalcin (-8.6%), bone alkaline phosphatase (-11.5%), serum (-16.3%) and urine (-13.0%) type-1 collagen C-telopeptide in the HCaMW group compared to the placebo group, where all biochemical indices increased after 6 months. The additive effect of a small vitamin D supplement (400 iu/day) was also evaluated. In women receiving vitamin D in addition to HCaMW, the decrease in bone indices was not found to be greater than in women drinking only the HCaMW. A daily supplement of 596 mg of Ca through the consumption of 1 l of HCaMW was able to lower serum PTH and the indices of bone turnover in postmenopausal women with a low Ca intake. This could contribute to the repair of calcium deficiency and to the reduction of age-related bone loss in this population.

Small bowel absorption of magnesium and calcium sulphate from a natural mineral water in subjects with ileostomy

BACKGROUND

In many developed countries, magnesium and calcium intakes do not reach recommendations for a large part of the population. Mineral water may be a useful alternative source of dietary minerals, especially in groups of people at risk for developing deficiency due to low intakes.

AIM

To assess if the addition of a natural and mineral-rich water increased small bowel mineral absorption in people with ileostomy.

METHODS

A controlled randomised crossover study with two periods of two days each and a minimum 5 days of washout was performed in six ileostomy subjects. Apparent mineral absorption from 0.5 L of natural mineral water with either a high or a low mineral content consumed in the fasting state was compared. The daily addition of minerals corresponded to 2.3mmol magnesium, 6.9 mmol calcium and 7.7mmol sulphate. Ileostomy effluents were sampled and analysed for magnesium, calcium and total sulphate.

RESULTS

When compared with the control, the median absorbed amount of magnesium increased from 0.8 (0-1.34) mmol/d to 1.2 (0.8-1.9) mmol/d,which corresponded to a 30% increase (P = 0.028). Median amount of calcium absorbed increased from 8.3 (6.7-13.6) mmol/d to 14.8 (8.3-20.4) mmol/d, i. e. a 45% increase (P = 0.027). The sulphate absorption increased from 1.9 (1.3-2.2) mmol/d to 5.1 (4.2-6.8) mmol/d,which corresponded to 197 % increase (P = 0.028).

CONCLUSIONS

The mineral-rich water increased absorption of both magnesium and calcium and can therefore be used as an additional source of minerals. However, consumption with meals may be preferred.

Higher calcium urinary loss induced by a calcium sulphate-rich mineral water intake than by milk in young women

It is well known that the intestinal availability of Ca from Ca-rich mineral waters is equivalent to that of milk Ca. However, the effect of associated anions on Ca urinary loss needs to be addressed. The aim of the current study was to compare, under ordinary conditions of consumption, milk and a SO4-rich mineral water as the Ca provider in a large number of subjects consuming the same quantity of Ca from the two sources in a crossover study lasting for an extended period. Thirty-seven healthy women completed a 12-week protocol, divided into four periods of 3 weeks (W). In the first (W1-3) and third (W6-9) periods, dietary Ca intake was restricted to 600 mg/d. In the second (W4-6) and final (W10-12) periods, either 400 ml/d medium-fat milk or 1 litre of a Ca- and SO4-rich mineral water, each providing about 480 mg Ca/d, was added to the diet in a random manner. Dietary evaluation, blood and urinary measures were performed during the last week (W6 and W12) of each Ca supplementation period. The urinary excretion of Ca was higher (0.5 mmol/d more) with water than with milk (P<0.001). An examination of all the dietary factors known to influence calciuria suggested that the acidogenic action of SO4 was responsible for this increased calciuria. Thus, despite an equal Ca intake and assuming an unchanged intestinal absorption, these results suggest that Ca balance is better with milk consumption than with CaSO4-rich water.

Mineral water intake reduces blood pressure among subjects with low urinary magnesium and calcium levels

Background

Several previous epidemiological studies have shown a relation between drinking water quality and death in cardiovascular disease whereas others have not found such a relationship. An intervention study was undertaken to evaluate the effect of water with added magnesium and natural mineral water on blood pressure.

Methods

A group of 70 subjects with borderline hypertension was recruited and consumed 1) a water low in minerals, 2) magnesium enriched water or 3) natural mineral water, in a random, double blind fashion during four weeks.

Results

Among persons with an initial low excretion of magnesium or calcium in the urine, the urinary excretion of magnesium was increased in the groups consuming the two waters containing magnesium after 4 weeks. A significant decrease in blood pressure was found in the group consuming mineral water at 2 and 4 weeks.

Conclusion

The results suggest that minerals taken in water are significant for the body burden and that an intake of mineral water among persons with a low urinary excretion of magnesium or calcium may decrease the blood pressure. Further studies should investigate the extent of mineral deficiency in different populations and the efficiency of different vehicles for supplying minerals, particularly magnesium and calcium.

Calcium bioavailability from a calcium-rich mineral water, with some observations on method

GOALS

The study was designed to determine whether high-calcium mineral water is an efficient additional source of dietary calcium, optimizing a method for calcium determination never used for mineral waters.

BACKGROUND

It is generally agreed that an adequate calcium intake is necessary for the acquisition of an ideal peak bone mass and for the maintenance of the bone mineral density in adults, in postmenopausal women, and in the elderly. Mineral waters are calorie free, and some, with high calcium levels, might be significant sources of calcium.

STUDY

The availability of the calcium contained in a high-calcium mineral water was measured in 27 healthy subjects. In 8 subjects the calcium availability of the water was compared with the calcium availability ingested with milk at the same calcium load. Milk and water were labeled extrinsically with 30 mg Ca. Fractional absorption from the oral dose was determined from plasma samples using ICP-MS technique.

RESULTS

At an ingested calcium load of 3.18 mmol, percentage of absorption for water averaged 22.53 +/- 2.53 (mean +/- SD) for men, 22.57 +/- 2.10 (mean +/- SD) for premenopausal women and 21.62 +/- 3.12 (mean +/- SD) for postmenopausal women. Percentage absorption from milk was 23.15 +/- 4.06 (mean +/- SD).

DISCUSSION

The calcium from the mineral water is thus highly bioavailable, at least as bioavailable as milk calcium, and ICP-MS appears to represent a reliable and reproducible method for calcium absorption from alimentary sources.

Effect of acute oral calcium load on serum PTH and bone resorption in young healthy subjects: an overnight study

OBJECTIVE

To investigate the effects of a 400 mg acute oral calcium dose on PTH and bone resorption markers in a young, healthy population.

DESIGN

Fasting serum parathyroid hormone (PTH), C-telopeptides (CTX), total calcium (Ca), albumin and urinary calcium/creatinine ratio (uCa/Cr) were measured on two separate days: one before and the other 10 h after oral administration of 400 mg calcium. Serum 25-hydroxy vitamin D (25-OHD) status was assessed at baseline. Dietary calcium intake was assessed using a food frequency questionnaire (FFQ).

SUBJECTS

A total of 32 healthy, young adults (17 female, 15 male; mean+/-s.e.m. age: 21+/-1 y) took part in this study. Their mean (s.e.m.) calcium intake was 1125 (+/-56) mg/day.

INTERVENTION

Effervescent Sandocal 400 tablets dissolved in water.

RESULTS

After the calcium challenge, mean Ca and uCa/Cr ratio increased significantly, and both PTH and CTX concentrations were significantly lower. Multiple regression analysis showed no relationship between the response to the 400 mg load and previous dietary calcium intake (as assessed by FFQ) or serum 25-OHD.

CONCLUSION

We have shown that in a young, healthy population, 400 mg oral calcium can inhibit bone resorption (as measured by serum CTX) and PTH, and this appears to be independent of previous dietary calcium intake and vitamin D status.

Foods and new foods: the role of nutrition in skeletal health

GOALS

The objective of this paper was to present nutrients for bone health along with traditional foods and new foods that can provide the adequate amount of such nutrients.

BACKGROUND

Although bone mass and density are certainly determined by various concurrent factors such as genetics, hormones, physical activity, and nutrition, and although the genetic program has a critical role in growth and in bone peak development, for their realization an adequate nutritional intake of nutrients is always necessary and may represent a way to prevent bone diseases.

METHODS

The authors collected scientific data about new possible foods containing potential nutrients for bone health besides milk, dairy products, and supplementation in tablets.

RESULTS

There is much scientific evidence that calcium-rich mineral water, functional foods, soy products derived phytoestrogens, fortified foods, and vitamins K and E may play a important nutritional role in skeletal health.

CONCLUSION

Currently, it is possible to provide required bone nutrient intake for bone health in population subgroups intolerant or allergic to lactose and in those individuals who need a controlled intake of calories.

Changes in water intake of Northumbrian adolescents 1980 to 2000

OBJECTIVES

To determine: total water intake in young English adolescents; the relative importance of sources of water intake; and changes in water intake and sources of water between 1980 and 2000.

DESIGN

A cross-sectional observational study of the diets of 11-12-year-old children attending seven schools in south Northumberland, UK. The information obtained was compared with results from a similar survey carried out 20 years previously.

METHODS

All children attending these schools were invited to participate. They completed a three-day diet diary with an interview on the fourth day, on two occasions during the school year. Standard UK food composition tables were used and water intake from various sources calculated. Anthropometric and social class information was obtained.

RESULTS

Four hundred and twenty-four children completed all aspects of the study (64% of those eligible). The mean total water intake was 1,130 g d(-1), approximately the same as that recorded 20 years before. Water intake in relation to energy intake: water intake was 139 g MJ(-1) in boys and 143 g MJ(-1) in girls. Sixty-five per cent of water came from drinks and 35% from foods; very similar to proportions 20 years before. The sources of water in drinks had changed considerably, with a marked increase in consumption of soft drinks (especially carbonated drinks) and a decrease in consumption of hot drinks and milk. There were a few differences between sexes but little difference between social groups.

CONCLUSIONS

Total water intake was similar to that recorded 20 years previously and lower than intakes reported in other countries. Changes in the sources of water meant that less water consumed was likely to come from the tap in the house and more from drinks made elsewhere, than 20 years previously. These changes have implications for estimating fluoride intake in fluoridated areas.

Different acute responses of serum type I collagen telopeptides, CTX, NTX and ICTP, after repeated ingestion of calcium

BACKGROUND

N- and C-terminal fragments of type I collagen such as NTX, CTX and ICTP are released into circulation during bone resorption and can be quantified in serum. Their respective sensitivity as indices of osteoclastic activity was compared after a short-term inhibition of resorption induced by repeated drinking of calcium-fortified water.

METHODS

Serum NTX, CTX and ICTP were measured by specific immunoassays in one group of 15 subjects sampled at 08.00, 11.00, 14.00 and 17.00 (referred to as T0, T3h, T6h and T9h) and having ingested in two experimental periods 660 ml of either low-calcium mineral water or the same low-calcium mineral water fortified with calcium (300 mg/l) at three times (08.00, 11.00 and 14.00).

RESULTS

Oral intake of calcium-fortified water resulted in progressive decrease in serum CTX (by 38.7% at T3h, 61.0% at T6h and 60.4% at T9h) and NTX (by 19.0% at T3h, 24.1% at T6h and 25.2% at T9h) while serum ICTP concentrations were not significantly affected. Since ingestion of low-calcium water induced a modest but significant decrease in both CTX (-19.4%) and NTX (-10.6%) we compared the two sets of assays with repeated-measures two-factor analysis of variance with interaction. Ingestion of calcium-fortified water vs. low-calcium water resulted in a significant decrease in both serum CTX (time, P<0.0001; treatment, P<0.0001; time-by treatment, P<0.0001) and NTX (time, P<0.0001; treatment, P=0.0001; time-by treatment, P=0.0066).

CONCLUSIONS

CTX is more sensitive than NTX while ICTP is not sensitive to calcium-induced acute changes in osteoclastic activity. The present results stress the importance of choosing appropriate biochemical bone markers to demonstrate the effects of calcium on bone resorption.

Gustatory Evaluation of Still and Carbonated Waters: A Preference Rating Study

We studied the sensory preference for six still waters and four carbonated waters, nonflavored, by 11 tasting experts (4 women and 7 men). Five tasters rated the still waters, four tasters rated the carbonated water, and seven tasters rated twice on each of the still waters when evaluated with a dry red wine. All ratings were performed through answering a set of questions regarding the specific taste and/or smell of the waters. All tasters and the statistician were blinded to the water brands during rating and analysis. Multidimensional preference analysis and correspondence analysis were used to portray the underlying sensory preference. Still waters with higher mineral content tended to be less favorable for drinking purposes. On the other hand, carbonated waters with more minerals (but not over a certain limit) were favorable, and still waters with higher mineral content were preferable as mouth cleaners for red wine. The methodology can be carried to the food and beverage industries, to the functional foods industry, and to medical research where the preference of patients toward certain medications is of interest.

Caseinphosphopeptides in milk and fermented milk do not affect calcium metabolism acutely in postmenopausal women

BACKGROUND

Caseinphosphopeptides (CPPs) are formed in food processing or during digestion in the gastrointestinal tract. CPPs prevent the formation of insoluble calcium salts; thus, the hypothesis is that CPPs increase the absorption of calcium.

OBJECTIVE

We examined the effect of additional caseinphosphopeptides in milk and fermented milk on acute calcium metabolism by measuring intact PTH (iPTH), ionized calcium (iCa), total calcium (Ca) and phosphate (P) from serum, and 24-hour calcium from urine (U-Ca).

METHODS

The study consisted of two separate parts, both applying a double-blind randomized crossover study with two interventions, in nine postmenopausal women. The acute effect on calcium metabolism was analysed by measuring iPTH, iCa, Ca and P from serum during the first six hours after the administration of the study milks. U-Ca was analysed 24 hours prior to the study and 0, 2, 4, 6, 12 and 24 hours after the administration of the study milks. The study included two parts, both consisting of two study days with a one-week washout period in between. In the first part the effect of control milk and CPP-enriched milk was measured. The second part evaluated the effect of fermentation by giving subjects milk or fermented milk, both enriched with CPPs.

RESULTS

In the first part of the study there were no statistically significant differences in iPTH, iCa, Ca, P or U-Ca between the groups receiving control milk compared to CPP-containing milk. There was no difference in the AUC((0-6)) of iCa and iPTH. In the second part, fermentation did not affect calcium metabolism, when results from the CPP-enriched milk and CPP-enriched fermented milk groups were compared.

CONCLUSION

One gram of caseinphosphopeptides does not affect calcium metabolism acutely in postmenopausal women.

Contribution of mineral waters to dietary calcium and magnesium intake in a French adult population

OBJECTIVE

To assess the contribution of mineral water containing different amounts of calcium and magnesium to the total dietary intakes of these minerals

DESIGN

Matched case control study using data issued from the Supplementation en Vitamines et Minéraux Antioxydants (SU.VI.MAX) cohort.

SUBJECTS

Subjects were water consumers-240 men and 424 women-divided into the following 4 groups (n=166 per group): regular drinkers of a calcium-rich and magnesium-rich mineral water (calcium, 486 mg/L; magnesium, 84 mg/ L), drinkers of a water classified as a moderately mineralized content (calcium, 202 mg/L; magnesium, 36 mg/L), drinkers of 2 low-mineralized waters (calcium, 9.9 to 67.6 mg/L and magnesium, 1.6 to 2 mg/L, respectively), and drinkers of tap waters.

STATISTICAL ANALYSES

Quantitative data were compared using student's t test. Mean comparisons were performed in multivariate analysis by analysis of variance.

RESULTS

Dietary calcium intake provided by the various food groups did not differ between the 4 consumer groups, except for calcium provided by mineral water. According to its calcium concentration, mineral water may contribute to one fourth of the total daily calcium intake. Subjects who regularly drink mineral-rich water have a calcium intake that is significantly higher (P< 10(-3)) than those drinking either low-mineral-content water or tap water. Dietary magnesium intake provided by the various food groups did not differ between the 4 consumer groups, except for magnesium provided by mineral water. Depending on the magnesium concentration of the mineral water, it contributed 6% to 17% of total daily magnesium intake. Drinkers of magnesium-rich mineral water and water with a moderate mineral content had magnesium intakes significantly (P< 10(-3)) higher than those of drinkers on low-mineralized or tap water.

APPLICATIONS

Mineral-rich water may provide an important supplementary contribution to total calcium and magnesium intake. For dietetics professionals, it may provide-in place of the usual recommendations concerning the consumption of dairy products-a good way to improve calcium and magnesium intakes, particularly in subjects who don't like dairy products.