Dietary calcium and mineral/vitamin supplementation: a controversial problem

The Role of Macronutrients, Micronutrients and Flavonoid Polyphenols in the Prevention and Treatment of Osteoporosis

Osteoporosis is considered an age-related disorder of the skeletal system, characterized primarily by decreased bone mineral density (BMD), microstructural quality and an elevated risk of fragility fractures. This silent disease is increasingly becoming a global epidemic due to an aging population and longer life expectancy. It is known that nutrition and physical activity play an important role in skeletal health, both in achieving the highest BMD and in maintaining bone health. In this review, the role of macronutrients (proteins, lipids, carbohydrates), micronutrients (minerals—calcium, phosphorus, magnesium, as well as vitamins—D, C, K) and flavonoid polyphenols (quercetin, rutin, luteolin, kaempferol, naringin) which appear to be essential for the prevention and treatment of osteoporosis, are characterized. Moreover, the importance of various naturally available nutrients, whether in the diet or in food supplements, is emphasized. In addition to pharmacotherapy, the basis of osteoporosis prevention is a healthy diet rich mainly in fruits, vegetables, seafood and fish oil supplements, specific dairy products, containing a sufficient amount of all aforementioned nutritional substances along with regular physical activity. The effect of diet alone in this context may depend on an individual’s genotype, gene-diet interactions or the composition and function of the gut microbiota.

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.

Bone Mineral Density and Metabolism at an Early Stage of Menopause When Estrogen and Calcium Supplement Are Not Used and without the Interference of Major Confounding Variables

OBJECTIVES

To measure bone mineral density (BMD) and to screen for early biochemical abnormalities in bone mineral metabolism in the first five years of natural menopause when estrogen and calcium supplement are not used and in the absence of major confounding variables.

SETTING

Two homogeneous and comparable groups (n = 30) of healthy pre- and postmenopausal Caucasian women living in a northern region (latitude 46 degrees N) were recruited during the mid-Spring/Summer season in a cross-sectional design.

METHODS

Volumetric apparent BMAD (g/cm(3)) was calculated from areal BMD (g/cm(2)) which was evaluated by dual energy X-ray absorptiometry (Lunar) at both axial and peripheric (femur) sites using two sets of reference values (WHO criterion expressed as T-score and absolute values of areal density) in combination to bone specific biochemical measurements.

RESULTS

BMD and BM(A)D were significantly lower in postmenopausal women for all lumbar sites, but not for Ward's triangle and any other femoral sites whereas free deoxypyridinoline (Dpd), urinary biochemical marker of bone resorption, was markedly (p < 0.0001) greater. Their serum calcium and phosphate were significantly higher without a difference in 1,25(OH)(2)D(3) and PTH. The prevalence of osteopenia in pre- and postmenopausal women was about 2-fold lower in both groups (26.6 and 46.9%, respectively) when lumbar (L) spine and femur neck were combined and using the criteria based on reference values of areal density instead of T-scores.

CONCLUSIONS

The present study showed that the negative effects of estrogen deficiency on BMD and bone metabolism in early menopause occurred independently of the effect of major calcitropic hormones. Bone loss affects a non negligible proportion of premenopausal women. The prevalence of osteopenia in pre- and postmenopausal women varied according to the criterion used and anatomic site.

The Role of Calcium in Osteoporosis Drug Therapy

Great advances have been made in the field of osteoporosis treatment and prevention in recent years that have led to the availability of powerful new drugs. These drugs are viewed by patients and physicians as a major breakthrough in the management of osteoporosis. Unfortunately, this view has led many to ignore the importance of concurrent calcium supplementation to ensure the maximum benefit from these drugs, as evidenced by the recent decline in use of calcium supplements. As the majority of patients fail to consume the minimum recommended dietary intake of calcium, it is critical to recommend calcium supplements to raise total daily calcium intake to the levels needed to ensure maximum efficacy of osteoporosis treatments. Furthermore, osteoporosis drug labeling should be strengthened to encourage proper use of these drugs in combination with calcium supplements.

Dietary macro- and micronutrient intakes of nonsupplemented pre- and postmenopausal women with a perspective on menopause-associated diseases1

OBJECTIVES

To assess the dietary intakes and diet quality of menopausal women relative to premenopausal women, and to determine whether their diets are compatible with reducing risks of cardiovascular disease (CVD) and osteoporosis.

DESIGN

Cross-sectional study using 3-day food records and anthropometric measurements. Subjects Thirty apparently healthy, nonoestrogen using and nonsupplemented women menopausal since 3-5 years and 30 well-matched premenopausal women. Outcome measures Nutrient intakes, diet nutrient density, body mass index (BMI), waist circumference, waist-to-hip ratio and serum oestradiol.

RESULTS

Energy intake and body weight of pre- and postmenopausal women were comparable. Their BMI, waist circumference and waist-to-hip ratios were within healthy ranges. The diet of postmenopausal women was compatible (less total lipids and saturated fatty acids; more fibres, antioxidant vitamins and potassium) with North American nutritional recommendations linked to cardiovascular health. Their dietary iron intakes exceeded their reduced physiological need, which may jeopardize their cardiovascular system. Their calcium and vitamin D intakes were far below recommendations for healthy bones. Five other nutrients were also suboptimal. Phosphorus intake (high in both groups) correlated with dietary proteins, sulphur amino acids and calcium.

CONCLUSIONS

The diet of the postmenopausal women studied were more compatible with national nutritional recommendations than that of premenopausal controls. However, these postmenopausal women, not taking hormone replacement therapy (HRT) and having inadequate dietary calcium and vitamin D intakes, may be at increased risk of osteoporotic fracture later in life. More studies on CVD risk inherent to body iron accumulation involving a large number of postmenopausal women are warranted before planning public health measures regarding dietary iron intake.

Management of osteoporosis in patients with gastrointestinal diseases

Osteoporosis is a frequent complication in the course of various gastrointestinal disorders. Since its pathogenesis is complex, and incompletely understood in comparison to the well-known pathomechanism of postmenopausal osteoporosis, adequate management is difficult. We first summarize those therapeutic options which have strong evidence in postmenopausal osteoporosis and, thereafter, we review those in the context of different gastrointestinal diseases. Treatment of the underlying intestinal disorder seems to be most important to normalise altered bone metabolism and to prevent osteoporosis in patients with coeliac disease. In patients with osteoporosis associated with Crohn's disease, various treatment strategies (such as vitamin D, sodium fluoride, bisphosphonates) are discussed. In contrast to postmenopausal osteoporosis, interventional studies in secondary osteoporosis are often limited by the small study population and data about the efficacy of any treatment in prevention of fractures are therefore lacking. Well-conducted, controlled studies with the endpoint of preventing fractures are therefore required to optimise the treatment of osteoporosis in these patients.

Effect of continuous combined therapy with vitamin K(2) and vitamin D(3) on bone mineral density and coagulofibrinolysis function in postmenopausal women

OBJECTIVES

To investigate the therapeutic effect of combined use of vitamin K(2) and D(3) on vertebral bone mineral density in postmenopausal women with osteopenia and osteoporosis.

SUBJECTS AND METHODS

We enrolled 172 women with vertebral bone mineral density <0.98 g/cm(2) (osteopenia and osteoporosis) as measured by dual-energy X-ray absorptiometry. In this study, we employed the criteria for diagnosis of osteopenia and osteoporosis using dual energy X-ray absorptiometry proposed by the Japan Society of Bone Metabolism in 1996. Subjects were randomized into four groups (each having 43 subjects in vitamin K(2) therapy group, vitamin D(3) therapy group, vitamin K(2) and D(3) combined therapy group, or a control group receiving dietary therapy alone) and treated with respective agents for 2 years, with bone mineral density was measured prior to therapy and after 6, 12, 18, and 24 months of treatment. The bone metabolism markers analyzed were serum type 1 collagen carboxyterminal propeptide (P1CP), serum intact osteocalcin, and urinary pyridinoline. Tests of blood coagulation function consisted of measurement of activated partial thromboplastin time (APTT) and analysis of concentrations of antithrombin III (AT III), fibrinogen, and plasminogen.

RESULTS

Combined therapy with vitamin K(2) and D(3) for 24 months markedly increased bone mineral density (4.92 +/- 7.89%), while vitamin K(2) alone increased it only 0.135 +/- 5.44%. The bone markers measured, revealed stimulation of both bone formation and resorption activity. We observed an increase in coagulation and fibrinolytic activity that was within the normal range, suggesting that balance was maintained in the fibrinolysis-coagulation system.

CONCLUSIONS

Continuous combination therapy with vitamin K(2) and D(3) may be useful for increasing vertebral bone mass in postmenopausal women. Furthermore, the increase in coagulation function observed during this therapy was within the physiological range, and no adverse reactions were observed.

Effects of an osteoporosis prevention program incorporating tailored educational materials

PURPOSE

To evaluate the effects of two interventions on calcium intake and exercise and assess whether intervention effects varied as a function of participants' stage of change.

DESIGN

The study used a 2 by 2 factorial research design. Baseline, 3-, 6-, and 12-month follow-up data were collected.

SETTING

Twelve counties in western North Carolina.

SUBJECTS

Of 714 women recruited, 547 (76.6%) completed all data collection procedures.

INTERVENTION

One intervention, conducted at the individual level, compared the effects of tailored vs. nontailored educational materials. The tailored educational intervention was delivered via two packets of written materials and one telephone counseling session. The written materials and counseling session were tailored according to participants' current calcium intake and exercise level, perceived adequacy of these behaviors, stage of change, behavioral goals, and perceived barriers to change. A community-based intervention was also evaluated. This intervention, implemented in 6 of the 12 counties, included establishing an Osteoporosis Resource Center, conducting a workshop on osteoporosis prevention, and offering free bone density screening.

MEASURES

Outcome measures were calcium intake and exercise level. Stage of change was assessed as a moderating variable.

RESULTS

Irrespective of intervention group, among women not consuming adequate calcium at baseline, intake increased an average of about 500 mg/d over the course of the study. Changes involving exercise were more modest. Repeated measures regression analyses were used to evaluate intervention effects. The effect of the tailored educational intervention varied, in appropriate ways, among women in different stages of change at baseline (F2,527 = 6.37, p < .002). Among women in the Engaged stage, the tailored intervention was associated with a greater increase in calcium intake. In contrast, among women who were obtaining adequate calcium at baseline (i.e., Action stage), the tailored intervention appeared to forestall inappropriate increases in calcium intake. The community-based intervention had no consistent effects on calcium intake, either alone, or in combination with the tailored intervention. Finally, neither intervention had an effect on exercise, either alone or in combination.

CONCLUSIONS

Limited support for the superiority of tailored vs. nontailored educational interventions was found. The differential effects observed could be due to the telephone counseling received by women in the Tailored Education Group, however.