Osteoporosis: Nowson CA

Sanders KM, Nowson CA, Kotowicz MA, Briffa K, Devine A, Reid IR, Anonymous00074. · Department of Clinical and Biomedical Sciences, Barwon Health, University of Melbourne, Geelong, VIC, Australia. · Med J Aust. · Pubmed #19296813 No free full text.

Abstract: This position statement was prepared by the Working Group of the Australian and New Zealand Bone and Mineral Society and Osteoporosis Australia. The final statement was endorsed by the Endocrine Society of Australia. Currently, the balance of evidence remains in favour of fracture prevention from combined calcium and vitamin D supplementation in elderly men and women. Adequate vitamin D status is essential for active calcium absorption in the gut and for bone development and remodelling. In adults with a baseline calcium intake of 500-900 mg/day, increasing or supplementing this intake by a further 500-1000 mg/day has a beneficial effect on bone mineral density. Calcium intake significantly above the recommended level is unlikely to achieve additional benefit for bone health.

Daly RM, Petrass N, Bass S, Nowson CA. · Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences, Deakin University, Melbourne, Australia. · Am J Clin Nutr. · Pubmed #18326617 links to  free full text

Abstract: BACKGROUND: In a previous 2-y randomized controlled trial, we showed that calcium- and vitamin D3-fortified milk stopped or slowed bone loss at several clinically relevant skeletal sites in older men. OBJECTIVE: The present study aimed to determine whether the skeletal benefits of the fortified milk were sustained after withdrawal of the supplementation. DESIGN: One hundred nine men >50 y old who had completed a 2-y fortified milk trial were followed for an additional 18 mo, during which no fortified milk was provided. Bone mineral density (BMD) of the total hip, femoral neck, lumbar spine, and forearm was measured by using dual-energy X-ray absorptiometry. RESULTS: Comparison of the mean changes from baseline between the groups (adjusted for baseline age, BMD, total calcium intake, and change in weight) showed that the net beneficial effects of fortified milk on femoral neck and ultradistal radius BMD at the end of the intervention (1.8% and 1.5%, respectively; P < 0.01 for both) were sustained at 18-mo follow-up (P < 0.05 for both). The nonsignificant between-group differences at the total hip (0.8%; P = 0.17) also persisted at follow-up (0.7%; P = 0.10), but there were no lasting benefits at the lumbar spine. The average total dietary calcium intake in the milk supplementation group at follow-up approximated recommended amounts for Australian men >50 y old (1000 mg/d) but did not differ significantly from that in the control subjects (1021 versus 890 mg/d). CONCLUSION: Supplementation with calcium- and vitamin D3-fortified milk for 2 y may provide some sustained benefits for BMD in older men after withdrawal of supplementation.

MacInnis RJ, Cassar C, Nowson CA, Paton LM, Flicker L, Hopper JL, Larkins RG, Wark JD. · Cancer Epidemiology Centre, The Cancer Council Victoria, Melbourne, Australia. · J Bone Miner Res. · Pubmed #12968674 No free full text.

Abstract: Reported effects of body composition and lifestyle on bone mineral density in pre-elderly adult women have been inconsistent. In a co-twin study, we measured bone mineral density, lean and fat mass, and lifestyle factors. Analyzing within pair differences, we found negative associations between bone mineral density and tobacco use (2.3-3.3% per 10 pack-years) and positive associations with sporting activity and lean and fat mass. INTRODUCTION: Reported effects of body composition and lifestyle of bone mineral density in pre-elderly adult women have been inconsistent. METHODS: In a co-twin study of 146 female twin pairs aged 30 to 65 years, DXA was used to measure bone mineral density at the lumbar spine, total hip, and forearm, total body bone mineral content, and lean and fat mass. Height and weight were measured. Menopausal status, dietary calcium intake, physical activity, current tobacco use, and alcohol consumption were determined by questionnaire. Within-pair differences in bone measures were regressed through the origin against within-pair differences in putative determinants. RESULTS: Lean mass and fat mass were associated with greater bone mass at all sites. A discordance of 10 pack-years smoking was related to a 2.3-3.3% (SE, 0.8-1.0) decrease in bone density at all sites except the forearm, with the effects more evident in postmenopausal women. In all women, a 0.8% (SE, 0.3) difference in hip bone mineral density was associated with each hour per week difference in sporting activity, with effects more evident in premenopausal women. Daily dietary calcium intake was related to total body bone mineral content and forearm bone mineral density (1.4 +/- 0.7% increase for every 1000 mg). Lifetime alcohol consumption and walking were not consistently related to bone mass. CONCLUSION: Several lifestyle and dietary factors, in particular tobacco use, were related to bone mineral density. Effect sizes varied by site. Characterization of determinants of bone mineral density in midlife and thereafter may lead to interventions that could minimize postmenopausal bone loss and reduce osteoporotic fracture risk.