There is high quality evidence that vitamin D plus calcium is associated with a statistically significant reduction in incidence of new non-vertebral fractures .
Vitamin D alone is unlikely to prevent fractures in the doses and formulations tested so far in older people .
Supplements of vitamin D and calcium may prevent hip or any type of fracture .
There was a small but significant increase in gastrointestinal symptoms and renal disease associated with vitamin D and calcium .
This review found that there was no increased risk of death from taking calcium and vitamin
BACKGROUND Vitamin D and related compounds have been used to prevent  osteoporotic fractures in older people .
This is the third up date of a Cochrane review first published in 1996 .
OBJECTIVES To determine the effects of vitamin D or related compounds , with or without calcium , for preventing  fractures in post-menopausal women and older men .
Design of the Women's Health Initiative clinical trial and observational study. The Women's Health Initiative Study Group.
The Women 's Health Initiative ( WHI ) is a large and complex clinical investigation of strategies for the prevention and control of some of the most common causes of morbidity and mortality among postmenopausal women , including cancer , cardiovascular disease , and osteoporotic fractures . The WHI was initiated in 1992 , with a planned completion date of 2007 . Postmenopausal women ranging in age from 50 to 79 are enrolled at one of 40 WHI clinical centers nationwide into either a clinical trial ( CT ) that will include about 64,500 women or an observational study ( OS ) that will include about 100,000 women . The CT is design ed to allow r and omized controlled evaluation of three distinct interventions : a low-fat eating pattern , hypothesized to prevent breast cancer and colorectal cancer and , secondarily , coronary heart disease ; hormone replacement therapy , hypothesized to reduce the risk of coronary heart disease and other cardiovascular diseases and , secondarily , to reduce the risk of hip and other fractures , with increased breast cancer risk as a possible adverse outcome ; and calcium and vitamin D supplementation , hypothesized to prevent hip fractures and , secondarily , other fractures and colorectal cancer . Overall benefit-versus-risk assessment is a central focus in each of the three CT components . Women are screened for participation in one or both of the components -- dietary modification ( DM ) or hormone replacement therapy (HRT)--of the CT , which will r and omize 48,000 and 27,500 women , respectively . Women who prove to be ineligible for , or who are unwilling to enroll in , these CT components are invited to enroll in the OS . At their 1-year anniversary of r and omization , CT women are invited to be further r and omized into the calcium and vitamin D ( CaD ) trial component , which is projected to include 45,000 women . The average follow-up for women in either CT or OS is approximately 9 years . Concerted efforts are made to enroll women of racial and ethnic minority groups , with a target of 20 % of overall enrollment in both the CT and OS . This article gives a brief description of the rationale for the interventions being studied in each of the CT components and for the inclusion of the OS component . Some detail is provided on specific study design choices , including eligibility criteria , recruitment strategy , and sample size , with attention to the partial factorial design of the CT . Some aspects of the CT monitoring approach are also outlined . The scientific and logistic complexity of the WHI implies particular leadership and management challenges . The WHI organization and committee structure employed to respond to these challenges is also briefly described
There is high quality evidence that vitamin D plus calcium is associated with a statistically significant reduction in incidence of new non-vertebral fractures .
Vitamin D alone is unlikely to prevent fractures in the doses and formulations tested so far in older people .
Supplements of vitamin D and calcium may prevent hip or any type of fracture .
There was a small but significant increase in gastrointestinal symptoms and renal disease associated with vitamin D and calcium .
This review found that there was no increased risk of death from taking calcium and vitamin
BACKGROUND Vitamin D and related compounds have been used to prevent  osteoporotic fractures in older people .
This is the third up date of a Cochrane review first published in 1996 .
OBJECTIVES To determine the effects of vitamin D or related compounds , with or without calcium , for preventing  fractures in post-menopausal women and older men .