Subgroup analyses showed that these results were generally consistent regardless of the calcium or vitamin D dose , sex , fracture history , dietary calcium intake , and baseline serum 25-hydroxyvitamin D concentration .
Conclusions and Relevance In this meta- analysis of r and omized clinical trials , the use of supplements that included calcium , vitamin D , or both compared with placebo or no treatment was not associated with a lower risk of fractures  among community-dwelling older adults .
Importance The increased social and economic burdens for osteoporosis-related fractures worldwide make the prevention of such injuries a major public health goal .
Previous studies have reached mixed conclusions regarding the association between calcium , vitamin D , or combined calcium and vitamin D supplements and fracture incidence in older adults .
Objective To investigate whether calcium , vitamin D , or combined calcium and vitamin D supplements are associated with a lower fracture incidence in community-dwelling older adults .
Vitamin D Supplementation and Fracture Incidence in Elderly Persons
Vitamin D deficiency is common in elderly persons , especially those with hip fracture [ 1 , 2 ] . It is caused by low exposure to sunshine , decreased synthesis of vitamin D3 in the aging skin , and a diet low in vitamin D [ 3 , 4 ] . The mean vitamin D intake in elderly persons in the Netherl and s is about 100 IU/d , half that of elderly persons in the United States [ 5 ] . Most of this vitamin D comes from margarine , which is the only vitamin D-supplemented food in the Netherl and s ( 3 IU/g ) . In vitamin D deficiency , the low serum concentration of 25-hydroxyvitamin D [ 25(OH)D ] leads to a low 1,25-dihydroxyvitamin D [ 1,25(OH)2D ] concentration and then to a higher serum parathyroid hormone concentration , especially in the winter [ 6 - 10 ] . Histologically , the increased parathyroid activity is associated with high bone turnover , leading to cortical bone loss and low density bone [ 5 , 11 ] , which may lead to hip fracture . We previously studied the effects of vitamin D supplementation in residents of a home for the elderly and residents of a nursing home [ 10 ] .  Vitamin D3 , 400 IU/d , led to an adequate increase of the serum 25(OH)D concentration , to a small but significant increase of the serum 1,25(OH)2D concentration , and to a decrease of the serum concentration of intact parathyroid hormone . It was recently observed [ 12 , 13 ] that bone mineral density at the hip is positively related to serum 25(OH)D concentration in postmenopausal and elderly women . Therefore , it might be expected that vitamin D supplementation would increase bone mineral density in elderly persons deficient in vitamin D. In line with this expectation , it was shown that vitamin D supplementation prevented bone loss from the spine during the winter in postmenopausal women [ 14 ] . These results suggest that vitamin D supplementation may reduce the incidence of hip fractures , because bone strength shows a strong correlation with bone mineral density [ 15 ] . However , increasing bone mineral density through a therapeutic intervention does not necessarily lead to increased bone strength , as has been shown with sodium fluoride [ 16 ] . Bone structure and bone quality are also determinants of bone strength [ 17 ] , and falls are a risk factor for hip fractures [ 18 ] . Therefore , hip fracture should be the outcome criterion in studies on the effect of vitamin D supplementation . Intervention studies on the prevention of osteoporotic fractures necessitate large numbers of patients , because the outcome has an annual incidence of 0.5 % to 4 % in the elderly population [ 19 ] . We report the results of a large-scale , prospect i ve study on the effect of vitamin D supplementation on the incidence of hip and other osteoporotic fractures . Methods Participants The study included 2578 persons ( 1916 women and 662 men ) 70 years of age and older ( mean age SD , 80 6 years ; range , 70 to 97 years ) . Participants were recruited from general practitioners , from apartment houses for elderly persons , and from homes for elderly persons in Amsterdam and its vicinity . Persons recruited from practitioners were living independently ; those recruited from apartment houses and homes were receiving some care , but less than they would have received in a nursing home . Participants had to be reasonably healthy and able to give informed consent . Persons with a history of hip fracture or total hip arthroplasty , known hypercalcemia , sarcoidosis , or recent urolithiasis ( < 5 years earlier ) were excluded . Patients who had diseases or who used medications that influence bone metabolism ( such as thyroid disease or glucocorticoid medication ) were not excluded . The spontaneous use of vitamin D supplements and multivitamins was discouraged , but the prescription practice s of the general practitioners were not altered . All vitamin use was carefully documented . The study was approved by the Ethical Review Board of the Vrije Universiteit Hospital , and all participants gave informed consent . Study Design After checking the inclusion and exclusion criteria and obtaining informed consent , the participants were r and omly assigned to receive either active treatment with vitamin D3 or placebo . The study was double-blind , and r and omization was done in blocks of 10 per general practice , apartment house , or home . R and omization lists were made using a computerized r and om-number generator . Lists in sealed envelopes were sent to the hospital pharmacy for assignment . Each participant took either one tablet per day that contained vitamin D3 , 400 IU , or one placebo tablet per day that was identical in appearance and taste to the vitamin tablet . After enrollment , the participants received the first container of tablets ( 210 tablets ) . The container was replaced every 6 months with a full container . All participants were also advised in writing to consume at least three servings of dairy products per day ( for example , 1 glass of milk , 1 cup of yogurt , and 1 slice of cheese ) to ensure a calcium intake of at least 800 to 1000 mg/d . The study was started in August 1988 . The last participant was enrolled in December 1990 , and all participants had stopped using study medication by December 1993 . The follow-up period had been planned to last no more than 3 years , but because the number of hip fractures during the study was lower than expected , a 6-month extension was planned . The study participants thus received medication for 3 to 3.5 years ; those who received it for 3.5 years were those who consented to the 6-month extension . Total follow-up was to a maximum of 4 years . Data collected at baseline included an  outdoor activity score  ( 1 equals going outdoors less than once a week ; 2 equals going outdoors 1 or 2 times per week ; and 3 equals going outdoors 3 times per week or more ) and a score for sunshine exposure ( when outside : 1 equals in the shade as much as possible ; 2 equals sometimes in sunshine ; 3 equals much exposure to sunshine ) . These scores show a positive relation with serum 25(OH)D concentration [ 3 ] . Mobility was estimated by a walking score that ranged from 1 ( unable to walk ) to 5 ( walks independently a fair distance on any surface ) [ 20 ] . The dietary calcium intake from dairy products was estimated in a subset of 348 women by using a question naire , as described previously [ 21 ] . The participants were evaluated annually with a question naire on hip fractures , other peripheral fractures , outdoor score , sunshine exposure score , use of vitamin supplements , and walking score . Each general practitioner or caretaker was asked to immediately report change of address , hip fracture , or death . Hip fracture and death were verified by the general practitioner . All participants were followed for the maximal period of 4 years if possible , even if they had stopped using the trial medication , had sustained a fracture , or had moved to another city . To investigate possible selection bias , 267 potential participants in a home for the elderly and its adjunct apartments ( all residents of the institution ) were studied for baseline characteristics , including age , sex , sunshine exposure score , outdoor score , walking score , and reasons for nonparticipation . Compliance was checked when the tablet containers were replaced ( every 6 months ) , by question naire ( every year ) , and by measurement of the serum 25(OH)D concentration . Serum 25(OH)D concentration was measured at baseline and after 1 year in 270 persons who participated in a sub study investigating the effect of vitamin D supplementation on bone mineral density and bone turnover variables . This sub study included a nonr and om sample of participants from several apartment houses and homes for the elderly and is described in detail elsewhere [ 21 ] . In the same sub study , dietary calcium intake from diary products was assessed . Serum 25(OH)D concentration was also estimated during the third year of the study in February and March in a r and om sample of 96 participants drawn from the remaining study population . These participants received a letter giving them an appointment within 10 days ; the blood sample s were drawn at home . Serum 25(OH)D concentration was measured by competitive protein binding assay after being purified by gradient high-pressure liquid chromatography . The intra- and interassay coefficients of variation were 5 % and 6 % , respectively [ 22 ] . Statistical Analysis Baseline data of the vitamin D group and the placebo group were compared using t-tests ( age , calcium intake ) , chi-square tests ( sex , residence ) , and Wilcoxon rank-sum tests ( scores ) . The serum 25(OH)D concentrations of both groups were compared using t-tests . Data on fractures and mortality were analyzed by survival analysis using log-rank tests , Cox proportional-hazards regression , and hazard rate ratios [ 23 ] . Hip fractures are presented using the Kaplan-Meier method . All participants were kept in the study as long as possible . The data were analyzed in two ways . The intention-to-treat analysis included all r and omly assigned participants for either the total follow-up period or until fracture , death , or loss to follow-up . The active treatment analysis included the participants as long as they stated that they were using the trial medication . Thus , the participants were included in the active treatment analysis until they stopped using the trial medication , regardless of whether a fracture occurred after they had stopped . Age , sex , and residence were added in both analyses as covariates to the Cox regression model . Because outdoor score , sunshine score , and walking score were interrelated ( correlation coefficients ranging from 0.21 to 0.59 ) and were likely to indicate general health or mobility , they were averaged over the years and added up to a sum score . For this purpose , the walking score was simplified ( 1 , 2 , or 3 equals 1 ; 4 equals 2 ; 5 equals 3 ) , because the lower walking scores applied to a few participants only . The result ing total score , ranging from 3 to 9 , was entered as a covariate in the model . The level of compliance ( weekly intake as reported on
Subgroup analyses showed that these results were generally consistent regardless of the calcium or vitamin D dose , sex , fracture history , dietary calcium intake , and baseline serum 25-hydroxyvitamin D concentration .
Conclusions and Relevance In this meta- analysis of r and omized clinical trials , the use of supplements that included calcium , vitamin D , or both compared with placebo or no treatment was not associated with a lower risk of fractures  among community-dwelling older adults .
Importance The increased social and economic burdens for osteoporosis-related fractures worldwide make the prevention of such injuries a major public health goal .
Previous studies have reached mixed conclusions regarding the association between calcium , vitamin D , or combined calcium and vitamin D supplements and fracture incidence in older adults .
Objective To investigate whether calcium , vitamin D , or combined calcium and vitamin D supplements are associated with a lower fracture incidence in community-dwelling older adults .