01.01.2006, 21:16
http://www.nutrition.org/cgi/content/abs...=nutrition
2005 The American Society for Nutritional Sciences J. Nutr. 135:2362-2366, October 2005
Human Nutrition and Metabolism
Calcium Supplementation Does Not Augment Bone Gain in Young Women Consuming Diets Moderately Low in Calcium1
M. Janet Barger-Lux, K. Michael Davies and Robert P. Heaney2
Creighton University, Omaha, Nebraska
2To whom correspondence should be addressed. E-mail: rheaney@creighton.edu .
In earlier observational work, the dietary calcium:protein ratio was directly related to bone accrual in healthy postadolescent women. In this study, we sought to test the hypothesis that augmented calcium intake would increase postadolescent skeletal consolidation, using a double-blind, randomized, placebo-controlled design. We recruited 152 healthy young women (age 23.1 ± 2.7 y, BMI 22.5 ± 3.0 kg/m2); their usual diets, as assessed by 7-d food diaries, were low in calcium (605 ± 181 mg/d; 15.1 ± 4.5 mmol/d) and in the calcium:protein ratio (10.1 ± 2.0 mg/g). The subjects were randomly assigned to supplemental calcium [500 mg calcium (12.5 mmol) as the carbonate, 3 times/d, with meals] or placebo capsules identical in appearance; all participants also took a daily multivitamin, and they were followed for up to 36 mo with bone densitometry (dual energy X-ray absorptiometry; DXA) at 6-mo intervals. A total of 121 subjects remained in the study for at least 12 mo (median time in the study, 35 mo), with a mean compliance level (observed/expected tablet consumption) of 87.7%. DXA data for these 121 subjects indicated modest but significant mean rates of increase (i.e., 0.24 to 1.10%/y) in bone mineral content (BMC; total body, total hip, and lumbar spine) and in lumbar spine bone mineral density (BMD) but no change in total hip BMD. None of these rates of change differed by group, i.e., calcium supplementation did not have any measurable effect on bone mass accrual. By midstudy, the calcium content of the subjects’ usual diets for both groups had risen by 15%. The combined effect of improved intakes of dietary calcium and the small amount of calcium added by the multivitamin tablets resulted in a mean calcium intake for the control group > 800 mg (20 mmol)/d, possibly at or near the threshold beyond which additional calcium has no further effect on bone accrual.
KEY WORDS: • calcium nutrition • calcium supplementation • young adults • bone mass • peak bone mass
”” Der Knochen besteht offenbar nicht nur aus Kalzium. Das ist das Ergebnis einer placebokontrollierten Interventionsstudie mit 150 jungen Frauen. Trotz geringer Calciumzufuhr über die Nahrung hatte das tägliche Schlucken von Kalziumtabletten ( 500 mg) keinerlei messbare Auswirkungen auf das Skelett. ( EULENSPIEGEL 5/6 –2005)
*****
1: Am J Clin Nutr. 2005 Nov;82(5):1107-14.
Comment in: Am J Clin Nutr. 2005 Nov;82(5):921-2.
Long-term protein intake and dietary potential renal acid load are associated with bone modeling and remodeling at the proximal radius in healthy children.
Alexy U, Remer T, Manz F, Neu CM, Schoenau E.
Research Institute of Child Nutrition, Dortmund, Germany.
BACKGROUND: Protein and alkalizing minerals are increasingly described as playing a major role in influencing bone status, not only in the elderly but also in children and adolescents. OBJECTIVE: We examined whether the long-term dietary protein intake and diet net acid load are associated with bone status in children. DESIGN: In a prospective study design in 229 healthy children and adolescents aged 6-18 y, long-term dietary intakes were calculated from 3-d weighed dietary records that were collected yearly over the 4-y period before a one-time bone analysis. Dietary acid load was characterized as potential renal acid load (PRAL) by using an algorithm including dietary protein, phosphorus, magnesium, and potassium. Proximal forearm bone variables were measured by peripheral quantitative computed tomography. RESULTS: After adjustment for age, sex, and energy intake and control for forearm muscularity, BMI, growth velocity, and pubertal development, we observed that long-term dietary protein intake was significantly positively associated with periosteal circumference (P < 0.01), which reflected bone modeling, and with cortical area (P < 0.001), bone mineral content (P < 0.01), and polar strength strain index (P < 0.0001), which reflected a combination of modeling and remodeling. Children with a higher dietary PRAL had significantly less cortical area (P < 0.05) and bone mineral content (P < 0.01). Long-term calcium intake had no significant effect on any bone variable. CONCLUSIONS: Long-term dietary protein intake appears to act anabolically on diaphyseal bone strength during growth, and this may be negated, at least partly, if dietary PRAL is high, ie, if the intake of alkalizing minerals is low.
PMID: 16280446 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov/entrez/query...t=Abstract
( Übersetzung: Eulenspiegel 5/6 2005)
Fleisch statt Kalzium
Auch eine prospektive Studie mit Kindern aus Deutschland bestätigt, dass die Calciumzufuhr keine positive Auswirkungen auf die Knochengesundheit hat. Dafür staunten die Forscher aus Dortmund nicht schlecht, als die Daten einen ganz anderen Schutzfaktor preisgaben: das Eiweiß ( welches denn????) . Je mehr davon verzehrt wurde, desto stabiler waren die Knochen.
Die o.g. 2 Veröffentlichungen werden der „Milchwerbung“ wohl nicht so recht „schmecken“, wenn sich doch das „größte Zugpferd“ für eine empfohlene Osteoporoseprophylaxe als „Ente“ erweist......
Uli
2005 The American Society for Nutritional Sciences J. Nutr. 135:2362-2366, October 2005
Human Nutrition and Metabolism
Calcium Supplementation Does Not Augment Bone Gain in Young Women Consuming Diets Moderately Low in Calcium1
M. Janet Barger-Lux, K. Michael Davies and Robert P. Heaney2
Creighton University, Omaha, Nebraska
2To whom correspondence should be addressed. E-mail: rheaney@creighton.edu .
In earlier observational work, the dietary calcium:protein ratio was directly related to bone accrual in healthy postadolescent women. In this study, we sought to test the hypothesis that augmented calcium intake would increase postadolescent skeletal consolidation, using a double-blind, randomized, placebo-controlled design. We recruited 152 healthy young women (age 23.1 ± 2.7 y, BMI 22.5 ± 3.0 kg/m2); their usual diets, as assessed by 7-d food diaries, were low in calcium (605 ± 181 mg/d; 15.1 ± 4.5 mmol/d) and in the calcium:protein ratio (10.1 ± 2.0 mg/g). The subjects were randomly assigned to supplemental calcium [500 mg calcium (12.5 mmol) as the carbonate, 3 times/d, with meals] or placebo capsules identical in appearance; all participants also took a daily multivitamin, and they were followed for up to 36 mo with bone densitometry (dual energy X-ray absorptiometry; DXA) at 6-mo intervals. A total of 121 subjects remained in the study for at least 12 mo (median time in the study, 35 mo), with a mean compliance level (observed/expected tablet consumption) of 87.7%. DXA data for these 121 subjects indicated modest but significant mean rates of increase (i.e., 0.24 to 1.10%/y) in bone mineral content (BMC; total body, total hip, and lumbar spine) and in lumbar spine bone mineral density (BMD) but no change in total hip BMD. None of these rates of change differed by group, i.e., calcium supplementation did not have any measurable effect on bone mass accrual. By midstudy, the calcium content of the subjects’ usual diets for both groups had risen by 15%. The combined effect of improved intakes of dietary calcium and the small amount of calcium added by the multivitamin tablets resulted in a mean calcium intake for the control group > 800 mg (20 mmol)/d, possibly at or near the threshold beyond which additional calcium has no further effect on bone accrual.
KEY WORDS: • calcium nutrition • calcium supplementation • young adults • bone mass • peak bone mass
”” Der Knochen besteht offenbar nicht nur aus Kalzium. Das ist das Ergebnis einer placebokontrollierten Interventionsstudie mit 150 jungen Frauen. Trotz geringer Calciumzufuhr über die Nahrung hatte das tägliche Schlucken von Kalziumtabletten ( 500 mg) keinerlei messbare Auswirkungen auf das Skelett. ( EULENSPIEGEL 5/6 –2005)
*****
1: Am J Clin Nutr. 2005 Nov;82(5):1107-14.
Comment in: Am J Clin Nutr. 2005 Nov;82(5):921-2.
Long-term protein intake and dietary potential renal acid load are associated with bone modeling and remodeling at the proximal radius in healthy children.
Alexy U, Remer T, Manz F, Neu CM, Schoenau E.
Research Institute of Child Nutrition, Dortmund, Germany.
BACKGROUND: Protein and alkalizing minerals are increasingly described as playing a major role in influencing bone status, not only in the elderly but also in children and adolescents. OBJECTIVE: We examined whether the long-term dietary protein intake and diet net acid load are associated with bone status in children. DESIGN: In a prospective study design in 229 healthy children and adolescents aged 6-18 y, long-term dietary intakes were calculated from 3-d weighed dietary records that were collected yearly over the 4-y period before a one-time bone analysis. Dietary acid load was characterized as potential renal acid load (PRAL) by using an algorithm including dietary protein, phosphorus, magnesium, and potassium. Proximal forearm bone variables were measured by peripheral quantitative computed tomography. RESULTS: After adjustment for age, sex, and energy intake and control for forearm muscularity, BMI, growth velocity, and pubertal development, we observed that long-term dietary protein intake was significantly positively associated with periosteal circumference (P < 0.01), which reflected bone modeling, and with cortical area (P < 0.001), bone mineral content (P < 0.01), and polar strength strain index (P < 0.0001), which reflected a combination of modeling and remodeling. Children with a higher dietary PRAL had significantly less cortical area (P < 0.05) and bone mineral content (P < 0.01). Long-term calcium intake had no significant effect on any bone variable. CONCLUSIONS: Long-term dietary protein intake appears to act anabolically on diaphyseal bone strength during growth, and this may be negated, at least partly, if dietary PRAL is high, ie, if the intake of alkalizing minerals is low.
PMID: 16280446 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov/entrez/query...t=Abstract
( Übersetzung: Eulenspiegel 5/6 2005)
Fleisch statt Kalzium
Auch eine prospektive Studie mit Kindern aus Deutschland bestätigt, dass die Calciumzufuhr keine positive Auswirkungen auf die Knochengesundheit hat. Dafür staunten die Forscher aus Dortmund nicht schlecht, als die Daten einen ganz anderen Schutzfaktor preisgaben: das Eiweiß ( welches denn????) . Je mehr davon verzehrt wurde, desto stabiler waren die Knochen.
Die o.g. 2 Veröffentlichungen werden der „Milchwerbung“ wohl nicht so recht „schmecken“, wenn sich doch das „größte Zugpferd“ für eine empfohlene Osteoporoseprophylaxe als „Ente“ erweist......
Uli