Optimal vitamin D status: a critical analysis on the basis of evidence-based medicine. A randomised, controlled comparison of different calcium and vitamin D supplementation regimens in elderly women after hip fracture: The Nottingham Neck of Femur (NONOF) Study. Prevention of hip fractures by correcting calcium and vitamin D insufficiencies in elderly people. Randomised controlled trial of calcium and supplementation with cholecalciferol (vitamin D3) for prevention of fractures in primary care Vitamin D3 and calcium to prevent hip fractures in elderly women. Can vitamin D supplementation reduce the risk of fracture in the elderly? A randomized controlled trial. Use of Calcium Supplements, Vitamin D Supplements and Specific Osteoporosis Drugs Among French Women Aged 75–85 Years: Patterns of Use and Associated Factors Health risks and benefits from calcium and vitamin D supplementation: Women's Health Initiative clinical trial and cohort study Calcium plus vitamin D supplementation and the risk of breast cancer. Calcium, vitamin D, milk consumption, and hip fractures: a prospective study among postmenopausal women. Long-term effects of nutrient intervention on markers of bone remodeling and calciotropic hormones in late-postmenopausal women. Investigation of Bone Health Subsequent to Vitamin D Supplementation in Children Following Burn Injury. Oral vitamin D3 and calcium for secondary prevention of low-trauma fractures in elderly people (Randomised Evaluation of Calcium Or vitamin D, RECORD): a randomised placebo-controlled trial. Associations of vitamin D status with bone mineral density, bone turnover, bone loss and fracture risk in healthy postmenopausal women. The OFELY study. Combined Calcium and Vitamin D3 Supplementation in Elderly Women: Confirmation of Reversal of Secondary Hyperparathyroidism and Hip Fracture Risk: The Decalyos II Study The Women's Health Initiative calcium-vitamin D trial: overview and baseline characteristics of participants. Vitamin D and calcium supplementation reduces cancer risk: results of a randomized trial. Vitamin D Status and Impact of Vitamin D3 and/or Calcium Supplementation in a Randomized Pilot Study in the Southeastern United States A comparison of the effects of alfacalcidol treatment and vitamin D2 supplementation on calcium absorption in elderly women with vertebral fractures Vitamin D: do we get enough? Serum 25-Hydroxyvitamin D Concentrations and Risk for Hip Fractures Response to teriparatide in patients with baseline 25-hydroxyvitamin D insufficiency or sufficiency. Effect of monthly high-dose vitamin D supplementation on falls and non-vertebral fractures: secondary and post-hoc outcomes from the randomised, double-blind, placebo-controlled ViDA trial.
CONTEXT Public health authorities around the world recommend widely variable supplementation strategies for adults , whereas several professional organizations , including The Endocrine Society , recommend higher supplementation . METHODS We analyzed published r and omized controlled clinical trials to define the optimal intake or vitamin D status for bone and extraskeletal health . CONCLUSIONS The extraskeletal effects of vitamin D are plausible as based on pre clinical data and observational studies . However , apart from the beneficial effects of 800 IU/d of vitamin D3 for reduction of falls in the elderly , causality remains yet unproven in r and omized controlled trials ( RCTs ) . The greatest risk for cancer , infections , cardiovascular and metabolic diseases is associated with 25-hydroxyvitamin D ( 25OHD ) levels below 20 ng/mL. There is ample evidence from RCTs that calcium and bone homeostasis , estimated from serum 1,25-dihydroxyvitamin D and PTH , calcium absorption , or bone mass , can be normalized by 25OHD levels above 20 ng/mL. Moreover , vitamin D supplementation ( 800 IU/d ) in combination with calcium can reduce fracture incidence by about 20 % . Such a dose will bring serum levels of 25OHD above 20 ng/mL in nearly all postmenopausal women . Based on calculations of the metabolic clearance of 25OHD , a daily intake of 500 - 700 IU of vitamin D3 is sufficient to maintain serum 25OHD levels of 20 ng/mL. Therefore , the recommendations for a daily intake of 1500 - 2000 IU/d or serum 25OHD levels of 30 ng or higher for all adults or elderly subjects , as suggested by The Endocrine Society Task Force , are premature . Fortunately , ongoing RCTs will help to guide us to solve this important public health question BACKGROUND survivors of hip fracture are at 5- to 10-fold risk of a second hip fracture . There is little consensus about secondary prevention . Many are given calcium and vitamin D , but the evidence supporting this is circumstantial . OBJECTIVE to compare the effects of different calcium and vitamin D supplementation regimens on bone biochemical markers , bone mineral density and rate of falls in elderly women post-hip fracture . DESIGN r and omised controlled trial . SETTING orthogeriatric rehabilitation ward . METHODS 150 previously independent elderly women , recruited following surgery for hip fracture , were assigned to receive a single injection of 300,000 units of vitamin D(2 ) , injected vitamin D(2 ) plus 1 g/day oral calcium , 800 units/day oral vitamin D(3 ) plus 1 g/day calcium , or no treatment . Follow-up was one year , with measurement of 25-hydroxyvitamin D , parathyroid hormone , bone mineral density , and falls . RESULTS mean 25-hydroxyvitamin D increased and mean parathyroid hormone was suppressed in all the actively treated groups , more so in the group receiving combined oral vitamin D and calcium . Twenty per cent of participants injected with vitamin D were deficient in 25-hydroxyvitamin D a year later . Bone mineral density showed small but statistically significant differences of up to 4.6 % between actively treated groups and placebo . Relative risk of falling in the groups supplemented with vitamin D was 0.48 ( 95 % CI 0.26 - 0.90 ) compared with controls . CONCLUSION Vitamin D supplementation , either orally or with injected vitamin D , suppresses parathyroid hormone , increases bone mineral density and reduces falls . Effects may be more marked with calcium co-supplementation . The 300,000 units of injected vitamin D may not last a whole year For a 50-year old caucasian woman today , the risk of a hip fracture over her remaining lifetime is about 17 % . Tomorrow the situation will clearly be worse because the continual increase in life expectancy will cause a 3-fold rise in worldwide fracture incidence over the next 60 years , particularly in women , but also in men . In addition , a secular increase in the incidence of hip fractures in individuals of the same age has been noted in both sexes by several investigators , and the cost of hip fractures is expected to dramatically increase in the next decades . Consequently , preventive strategies are urgently required . A great deal has been learned in recent years about the risk factors for hip fracture , the pathophysiology of this fracture , and the prediction of fracture risk , particularly through bone mass measurements on the hip and biochemical evaluations of parathyroid and vitamin D status . The two main determinants of hip fractures are falls and bone loss leading to an intrinsic femoral fragility . A substantial femoral bone loss continues throughout the old age , with a continuous and exponential increase in the risk of hip fracture , and any reduction or arrest of this loss will induce an important reduction in the incidence of hip fractures . A preventive effect on the risk of hip fracture may be partly achieved by using long term estrogen replacement therapy after menopause , but also by using vitamin D and calcium supplements for a late prevention in elderly people .  Vitamin D insufficiency and deficit in calcium intake are very common in elderly people living either in institutions or at home , particularly in Europe where dairy products are not fortified with vitamin D. The cumulative response to this deficit in calcium intake and low vitamin D status is a negative calcium balance which stimulates parathyroid hormone secretion . In 300 residents of nursing homes , we recently found a significant negative correlation between serum 25 OHD and log serum PTH after age-adjustment . In addition , in 446 elderly women living at home in 5 French cities and selected from the voting lists , we also found an age-adjusted relationship between serum 25 OHD and PTH concentrations . This senile secondary hyperparathyroidism is one of the determinants of femoral bone loss and can be reversed by calcium and vitamin D supplements . We have shown in a 3-year controlled prospect i ve study that the daily use of these supplements ( 1.2 g of calcium and 800 IU of vitamin D3 ) given in a large population of 3270 elderly ambulatory women living in nursing homes reduced of 23 % ( intention-to-treat analysis ) the number of hip fractures and other non vertebral fractures . In parallel , serum perathyroid hormone concentration was reduced of 28 % and low serum 25-hydroxyvitamin D concentration returned to normal values . After 18 months of treatment the bone density of the total proximal femoral region had increased 2.7 % the vitamin D3-calcium group and decreased 4.6 % in the placebo group ( p < 0.001 ) . This prevention is safe and can be recommended in people living in institutions . It could be also useful in other elderly subjects particularly at risk because of a low calcium intake , an absence of solar exposure and a previous history of falls . From the data of our study we assessed the economic consequences in terms of medical cost of this prevention . In case of treatment of all women living in nursing homes in France , this would saved FF 150000000 per year , the economic balance of prevention becoming positive as soon as the age of the beginning of the prevention reaches 73.5 years . It is now possible to partly stop bone loss in elderly people and it is never too late to prevent hip fractures with calcium and vitamin D supplements Abstract Objective To assess whether supplementation with calcium and cholecaliferol ( vitamin D3 ) reduces the risk of fracture in women with one or more risk factors for fracture of the hip . Design Pragmatic open r and omised controlled trial . Setting Practice nurse led clinics in primary care . Participants 3314 women aged 70 and over with one or more risk factors for hip fracture : any previous fracture , low body weight ( < 58 kg ) , smoker , family history of hip fracture , or fair or poor self reported health . Intervention Daily oral supplementation using 1000 mg calcium with 800 IU cholecaliferol and information leaflet on dietary calcium intake and prevention of falls , or leaflet only ( control group ) . Main outcome measures Primary outcome measure was all clinical fractures and secondary outcome measures were adherence to treatment , falls , and quality of life ( measured with the SF-12 ) . Results 69 % of the women who completed the follow-up question naire at 24 months were still taking supplements ( 55 % with inclusion of r and omised participants known to be alive ) . After a median follow-up of 25 months ( range 18 to 42 months ) , clinical fracture rates were lower than expected in both groups but did not significantly differ for all clinical fractures ( odds ratio for fracture in supplemented group 1.01 , 95 % confidence interval 0.71 to 1.43 ) . The odds ratio for hip fracture was 0.75 ( 0.31 to 1.78 ) . The odds of a woman having a fall at six and 12 months was 0.99 and 0.98 , respectively . Quality of life did not significantly differ between the groups . Conclusion We found no evidence that calcium and vitamin D supplementation reduces the risk of clinical fractures in women with one or more risk factors for hip fracture . Registration IS RCT N26118436 , controlled trials registry BACKGROUND Hypovitaminosis D and a low calcium intake contribute to increased parathyroid function in elderly persons .  Calcium and vitamin D supplements reduce this secondary hyperparathyroidism , but whether such supplements reduce the risk of hip fractures among elderly people is not known . METHODS We studied the effects of supplementation with vitamin D3 ( cholecalciferol ) and calcium on the frequency of hip fractures and other nonvertebral fractures , identified radiologically , in 3270 healthy ambulatory women ( mean [ + /- SD ] age , 84 + /- 6 years ) . Each day for 18 months , 1634 women received tricalcium phosphate ( containing 1.2 g of elemental calcium ) and 20 micrograms ( 800 IU ) of vitamin D3 , and 1636 women received a double placebo . We measured serial serum parathyroid hormone and 25-hydroxyvitamin D ( 25(OH)D ) concentrations in 142 women and determined the femoral bone mineral density at base line and after 18 months in 56 women . RESULTS Among the women who completed the 18-month study , the number of hip fractures was 43 percent lower ( P = 0.043 ) and the total number of nonvertebral fractures was 32 percent lower ( P = 0.015 ) among the women treated with vitamin D3 and calcium than among those who received placebo . The results of analyses according to active treatment and according to intention to treat were similar . In the vitamin D3-calcium group , the mean serum parathyroid hormone concentration had decreased by 44 percent from the base-line value at 18 months ( P < 0.001 ) and the serum 25(OH)D concentration had increased by 162 percent over the base-line value ( P < 0.001 ) . The bone density of the proximal femur increased 2.7 percent in the vitamin D3-calcium group and decreased 4.6 percent in the placebo group ( P < 0.001 ) . CONCLUSIONS Supplementation with vitamin D3 and calcium reduces the risk of hip fractures and other nonvertebral fractures among elderly women R and omized controlled trials have shown that a combination of vitamin D and calcium can prevent  fragility fractures in the elderly . Whether this effect is attributed to the combination of vitamin D and calcium or to one of these nutrients alone is not known . We studied if an intervention with 10 microg of vitamin D3 per day could prevent hip fracture and other osteoporotic fractures in a double-blinded r and omized controlled trial . Residents from 51 nursing homes were allocated r and omly to receive 5 ml of ordinary cod liver oil ( n = 569 ) or 5 ml of cod liver oil where vitamin D was removed ( n = 575 ) . During the study period of 2 years , fractures and deaths were registered , and the principal analysis was performed on the intention-to-treat basis . Biochemical markers were measured at baseline and after 1 year in a sub sample . Forty-seven persons in the control group and 50 persons in the vitamin D group suffered a  hip fracture . The corresponding figures for all nonvertebral fractures were 76 persons ( control group ) and 69 persons ( vitamin D group ) . There was no difference in the incidence of hip fracture ( p = 0.66 , log-rank test ) , or in the incidence of all nonvertebral fractures ( p = 0.60 , log-rank test ) in the vitamin D group compared with the control group . Compared with the control group , persons in the vitamin D group increased their serum 25-hydroxyvitamin D concentration with 22 nmol/liter ( p = 0.001 ) . In conclusion , we found that an intervention with 10 microg of vitamin D3 alone produced no fracture-preventing effect in a nursing home population of frail elderly people Background Despite the availability of effective preventive and curative medications for osteoporosis , and guidelines for its diagnosis and management , few individuals are treated for osteoporosis , even among those who have already had a fracture . Objectives Our objective was to describe the patterns of use of medication for osteoporosis , i.e. , calcium supplements , vitamin D supplements , and specific anti-osteoporotic drugs , such as bisphosphonates , in a large sample of French older women living at home , and to identify individual factors associated with use of these medications overall and in two specific clinical situations . Methods Cross-sectional analysis of data from 4,221 women aged 75–85 years who participated in a balance and mobility examination as part of the screening procedure for the Ossébo study , a r and omized controlled trial testing the effectiveness of exercise for the prevention of fall-related injuries .  Electoral rolls  were used to invite women in 16 towns to participate ( participation rate 10.3 % ) . Information collected through question naires included current medication use and , in particular , use of osteoporosis medications ( specific osteoporosis drugs , calcium and vitamin D supplementation ) in the past 6 months , and history of fracture since the age of 50 , including fracture locations . Fractures were categorized in three groups : no fracture , major osteoporotic fracture ( hip , humerus , wrist , pelvis , and vertebra ) , and other fracture . Results Nearly 48 % of the participants reported they did not take calcium or vitamin D supplements or any specific  osteoporosis drugs  . Of the 2,133 women who reported using osteoporosis medication , 85 % used  vitamin D supplements ( 25 % as the sole medication against this disease ) , 59 % calcium supplements , and 42 % a specific anti-osteoporotic drug ( 75 % of them combining it with vitamin D supplementation ) . The use of any osteoporosis medication was significantly associated ( p < 0.001 ) with a history of a major osteoporotic fracture , lower weight , dual-energy X-ray absorptiometry ( DXA ) bone-density measurement in the past 5 years , a cancer-screening examination in the past 5 years , and a positive attitude toward medication use in general . Living alone was associated with a lower likelihood of using a specific anti-osteoporotic drug  , and a higher education level was associated with a higher likelihood of vitamin D supplementation . Of the 1,553 women who had already had a major osteoporotic fracture , one-third ( 34.8 % ) were not taking any osteoporosis medication . In this subgroup , use of this medication was associated with the same factors as in the overall study population . In particular , neither older age nor a history of falls in the previous 12 months was associated with a higher likelihood of using osteoporosis medication . Among the 909 women who reported using a specific osteoporosis drug , vitamin D use was associated with a higher educational level and a more frequent preventive attitude . Conclusion In France , as in other western countries , women aged 75 years and over are not managed according to guidelines . Further studies should address the barriers encountered in improving quality of care in osteoporosis management Summary The Women 's Health Initiative ( WHI ) double-blind , placebo-controlled clinical trial r and omly assigned 36,282 postmenopausal women in the U.S. to 1,000 mg elemental calcium carbonate plus 400 IU of vitamin D3 daily or placebo , with average intervention period of 7.0 years . The trial was design ed to test whether calcium plus vitamin D supplementation in a population in which the use of these supplements was widespread would reduce hip fracture , and secondarily , total fracture and colorectal cancer . Introduction This study further examines the health benefits and risks of calcium and vitamin D supplementation using WHI data , with emphasis on fractures , cardiovascular disease , cancer , and total mortality . Methods WHI calcium and vitamin D r and omized clinical trial ( CT ) data through the end of the intervention period were further analyzed with emphasis on treatment effects in relation to duration of supplementation , and these data were contrasted and combined with corresponding data from the WHI prospect i ve observational study ( OS ) . Results Among women not taking personal calcium or vitamin D supplements at baseline , the hazard ratio [ HR ] for hip fracture occurrence in the CT following 5 or more years of calcium and vitamin D supplementation versus placebo was 0.62 ( 95 % confidence interval ( CI ) , 0.38–1.00 ) . In combined analyses of CT and OS data , the corresponding HR was 0.65 ( 95 % CI , 0.44–0.98 ) . Supplementation effects were not apparent on the risks of myocardial infa rct ion , coronary heart disease , total heart disease , stroke , overall cardiovascular disease , colorectal cancer , or total mortality , while evidence for a reduction in breast cancer risk and total invasive cancer risk among calcium plus vitamin D users was only suggestive . Conclusion Though based primarily on a subset analysis , long-term use of calcium and vitamin D appears to confer a reduction that may be substantial in the risk of hip fracture among postmenopausal women . Other health benefits and risks of supplementation at doses considered , including an elevation in urinary tract stone formation , appear to be modest and approximately balanced BACKGROUND Although some observational studies have associated higher calcium intake and especially higher vitamin D intake and 25-hydroxyvitamin D levels with lower breast cancer risk , no r and omized trial has evaluated these relationships . METHODS Postmenopausal women ( N = 36 282 ) who were enrolled in a Women 's Health Initiative clinical trial were r and omly assigned to 1000 mg of elemental calcium with 400 IU of vitamin D(3 ) daily or placebo for a mean of 7.0 years to determine the effects of supplement use on incidence of hip fracture . Mammograms and breast exams were serially conducted . Invasive breast cancer was a secondary outcome . Baseline serum 25-hydroxyvitamin D levels were assessed in a nested case-control study of 1067 case patients and 1067 control subjects . A Cox proportional hazards model was used to estimate the risk of breast cancer associated with r and om assignment to calcium with vitamin D(3 ) . Associations between 25-hydroxyvitamin D serum levels and total vitamin D intake , body mass index ( BMI ) , recreational physical activity , and breast cancer risks were evaluated using logistic regression models . Statistical tests were two-sided . RESULTS Invasive breast cancer incidence was similar in the two groups ( 528 supplement vs 546 placebo ; hazard ratio = 0.96 ; 95 % confidence interval = 0.85 to 1.09 ) . In the nested case-control study , no effect of supplement group assignment on breast cancer risk was seen . Baseline 25-hydroxyvitamin D levels were modestly correlated with total vitamin D intake ( diet and supplements ) ( r = 0.19 , P < .001 ) and were higher among women with lower BMI and higher recreational physical activity ( both P < .001 ) . Baseline 25-hydroxyvitamin D levels were not associated with breast cancer risk in analyses that were adjusted for BMI and physical activity ( P(trend ) = .20 ) . CONCLUSIONS Calcium and vitamin D supplementation did not reduce invasive breast  cancer incidence in postmenopausal women . In addition , 25-hydroxyvitamin D levels were not associated with subsequent breast cancer risk . These findings do not support a relationship between total vitamin D intake and 25-hydroxyvitamin D levels with breast cancer risk BACKGROUND Short trials of calcium supplementation show that it reduces loss of bone density in postmenopausal women ; longer observational studies do not generally find a lower risk of hip fracture with higher-calcium diets . Fewer studies have focused on vitamin D in preventing postmenopausal osteoporosis or fractures . OBJECTIVE We assessed relations between postmenopausal hip fracture risk and calcium , vitamin D , and milk consumption . DESIGN In an 18-y prospect i ve analysis in 72 337 postmenopausal women , dietary intake and nutritional supplement use were assessed at baseline in 1980 and up date d several times during follow-up . We identified 603 incident hip fractures result ing from low or moderate trauma .  Relative risks ( RRs ) from proportional hazards models were controlled for other dietary and nondietary factors . RESULTS Women consuming > or = 12.5 microg vitamin D/d from food plus supplements had a 37 % lower risk of hip fracture ( RR = 0.63 ; 95 % CI : 0.42 , 0.94 ) than did women consuming < 3.5 microg/d . Total calcium intake was not associated with hip fracture risk ( RR = 0.96 ; 95 % CI : 0.68 , 1.34 for > or = 1200 compared with < 600 mg/d ) . Milk consumption was also not associated with a lower risk of hip fracture ( P for trend = 0.21 ) . CONCLUSIONS An adequate vitamin D intake is associated with a lower risk of osteoporotic hip fractures in postmenopausal women . Neither milk nor a high-calcium diet appears to reduce risk . Because women commonly consume less than the recommended intake of vitamin D , supplement use or dark fish consumption may be prudent BACKGROUND Adequate intakes of calcium and vitamin D reduce bone loss and fracture risk in the elderly . Other nutrients also affect bone health , and adequate intakes may influence bone turnover and balance . OBJECTIVE We compared the long-term effects on bone turnover markers and calciotropic hormones of a multinutrient supplement , a calcium and vitamin D supplement , and dietary instruction aim ed at increasing calcium intake through foods . DESIGN Ninety-nine healthy postmenopausal women participated in a 3-y , r and omized trial , receiving either 1 ) supplemental calcium ( 1450 mg/d ) and vitamin D [ 10 microg ( 400 IU)/d ] , 2 ) calcium , vitamin D , and other nutrients ( multinutrient supplement ) , or 3 ) dietary instruction ( dietary control group ) . Data are from 83 subjects who completed the trial . RESULTS Increases over baseline in calcium intakes and serum 25-hydroxyvitamin D concentrations were sustained over 3 y in all treatment groups . Circulating parathyroid hormone concentrations were reduced at year 1 in all treatment groups but trended toward baseline thereafter . Bone turnover markers followed a similar pattern , and none of the changes in biochemical concentrations differed significantly between groups . CONCLUSIONS All 3 interventions offer long-term feasibility for increasing calcium intake and serum 25-hydroxyvitamin D concentrations . The dietary addition of micronutrients implicated in skeletal physiology confers no obvious bone-sparing effect in healthy postmenopausal women beyond that of calcium and vitamin D alone . The attenuation over time in suppression of parathyroid hormone and bone turnover might help explain why nutrient intervention tends to have less of a bone-sparing effect than do skeletally active medications such as estrogen or bisphosphonates BACKGROUND The effect of supplemental vitamin D on fracture occurrence following burn injuries is unclear . The objective of this study was to evaluate postintervention incidence of fractures in children during the rehabilitative phase postburn ( PB ) following participation in a r and omized clinical trial of vitamin D supplementation . MATERIAL S AND METHODS Follow-up for fracture evaluation was obtained in 39 of 50 patients r and omized to daily enteral vitamin D2 , D3 , or placebo throughout the acute burn course .  Serum 25-hydroxyvitamin D , 1,25-dihydroxyvitamin D , D2 , D3 , calcitonin , and bone alkaline phosphatase ( BAP ) measurements were obtained PB day 7 , midpoint , discharge , and 1-year PB . Urinary calcium was obtained PB day 7 and midpoint . Dual-energy x-ray absorptiometry ( DXA ) was performed at discharge and 1-year PB . RESULTS Fractures were reported in 6 of 39 respondents . Four fractures occurred in the placebo group , 2 in the D2 group , and none in the D3 group . Serum vitamin D , calcitonin , BAP , and urinary calcium were similar between fracture groups . The group with fracture morbidity had larger burn size ( 83.8 % ± 4.9 % vs 53.0 % ± 2.9 % , P < .0001 ) , greater full-thickness burn ( 69.7 % ± 9.4 % vs 39.4 % ± 4.1 % , P = .02 ) , and increased incidence of inhalation injury ( 33 % vs 6 % , P = .04 ) . Decreased bone mineral density z score was noted at discharge in the placebo fracture compared with no-fracture group ( P < .05 ) . CONCLUSION This preliminary report suggests there may be benefit of vitamin D3 in reducing postdischarge fracture risk . Results reaffirm the importance of monitoring bone health in pediatric patients postburn BACKGROUND Elderly people who have a fracture are at high risk of another . Vitamin D and calcium supplements are often recommended for fracture prevention . We aim ed to assess whether vitamin D3 and calcium , either alone or in combination , were effective in prevention of secondary fractures . METHODS In a factorial- design trial , 5292 people aged 70 years or older ( 4481 [ 85 % ] of whom were women ) who were mobile before developing a low-trauma fracture were r and omly assigned 800 IU daily oral vitamin D3 , 1000 mg calcium , oral vitamin D3 ( 800 IU per day ) combined with calcium ( 1000 mg per day ) , or placebo .  Participants who were recruited in 21 UK hospitals were followed up for between 24 months and 62 months . Analysis was by intention-to-treat and the primary outcome was new low-energy fractures . FINDINGS 698 ( 13 % ) of 5292 participants had a new low-trauma fracture , 183 ( 26 % ) of which were of the hip . The incidence of new , low-trauma fractures did not differ significantly between participants allocated calcium and those who were not ( 331 [ 12.6 % ] of 2617 vs 367 [ 13.7 % ] of 2675 ; hazard ratio ( HR ) 0.94 [ 95 % CI 0.81 - 1.09 ] ) ; between participants allocated vitamin D3 and those who were not ( 353 [ 13.3 % ] of 2649 vs 345 [ 13.1 % ] of 2643 ; 1.02 [ 0.88 - 1.19 ] ) ; or between those allocated combination treatment and those assigned placebo ( 165 [ 12.6 % ] of 1306 vs 179 [ 13.4 % ] of 1332 ; HR for interaction term 1.01 [ 0.75 - 1.36 ] ) . The groups did not differ in the incidence of all-new fractures , fractures confirmed by radiography , hip fractures , death , number of falls , or quality of life . By 24 months , 2886 ( 54.5 % ) of 5292 were still taking tablets , 451 ( 8.5 % ) had died , 58 ( 1.1 % ) had withdrawn , and 1897 ( 35.8 % ) had stopped taking tablets but were still providing data for at least the main outcomes . Compliance with tablets containing calcium was significantly lower ( difference : 9.4 % [ 95 % CI 6.6 - 12.2 ] ) , partly because of gastrointestinal symptoms . However , potentially serious adverse events were rare and did not differ between groups . INTERPRETATION The findings do not support routine oral supplementation with calcium and vitamin D3 , either alone or in combination , for the prevention of further fractures in previously mobile elderly people INTRODUCTION Vitamin D status is considered as an important determinant of bone health but supplementation trials with vitamin D(3 ) have yielded conflicting results . The aim of this study was to investigate the associations between serum 25-hydroxyvitamin D ( 25-OH D ) , bone turnover markers , bone mineral density ( BMD ) , radius bone loss and incidence of fracture in postmenopausal women . METHODS 669 postmenopausal women ( mean age : 62.2 years ) belonging to a population -based cohort were followed prospect ively for a median of 11.2 years . At baseline , 25-OH D levels , BMD , bone turnover markers and clinical risk factors of osteoporosis were assessed . BMD loss at the radius was estimated by annual measurements of BMD and all incident fractures which occurred in 134 women were confirmed by radiographs . RESULTS 73 % and 35 % of women had serum 25-OH D levels below 75 and 50 nmol/l which correspond respectively to the median and lowest optimal values recently proposed for fracture prevention . 11 % of women had levels below 30 nmol/l . Serum 25-OH D correlated modestly with intact PTH ( r(2)=0.023 , p<0.0001 ) , but not with bone turnover markers or BMD at the hip and radius after adjustment for age . When levels of 25-OH D were considered as a continuous variable , there was no significant association between 25-OH D levels and radius BMD loss or fracture risk . After adjustment for age , there was no significant difference in incidence of fracture , BMD , radius BMD loss , bone turnover markers , grip strength and the percentage of fallers in the previous year between women with 25-OH D levels below or above 75 , 50 or 30 nmol/l . CONCLUSIONS In a population of home-dwelling healthy postmenopausal women with few of them with severe vitamin D deficiency , vitamin D status may not be an important determinant of bone health Vitamin D insufficiency and low calcium intake contribute to increase parathyroid function and bone fragility in elderly people .  Calcium and vitamin D supplements can reverse secondary hyperparathyroidism thus preventing hip fractures , as proved by Decalyos I. Decalyos II is a 2-year , multicenter , r and omized , double-masked , placebo-controlled confirmatory study . The intention-to-treat population consisted of 583 ambulatory institutionalized women ( mean age 85.2 years , SD = 7.1 ) r and omized to the  calcium – vitamin D3  fixed combination group ( n= 199 ) ; the calcium plus vitamin D3 separate combination group ( n= 190 ) and the placebo group ( n= 194 ) . Fixed and separate combination groups received the same daily amount of calcium ( 1200 mg ) and vitamin D3 ( 800 IU ) , which had similar pharmacodynamic effects . Both types of calcium-vitamin D3 regimens increased serum 25-hydroxyvitamin D and decreased serum intact parathyroid hormone to a similar extent , with levels returning within the normal range after 6 months . In a subgroup of 114 patients  , femoral neck bone mineral density ( BMD ) decreased in the placebo group ( mean = –2.36 % per year , SD = 4.92 ) , while remaining unchanged in women treated with calcium-vitamin D3 ( mean = 0.29 % per year , SD = 8.63 ) . The difference between the two groups was 2.65 % ( 95 % CI = –0.44 , 5.75 % ) with a trend in favor of the active treatment group . No significant difference between groups was found for changes in distal radius BMD and quantitative ultrasonic parameters at the os calcis . The relative risk ( RR ) of HF in the placebo group compared with the active treatment group was 1.69 ( 95 % CI = 0.96 , 3.0 ) , which is similar to that found in Decalyos I ( RR = 1.7 ; 95 % CI = 1.0 , 2.8 ) . Thus , these data are in agreement with those of Decalyos I and indicate that calcium and vitamin D3 in combination reverse senile secondary hyperparathyroidism and reduce both hip bone loss and the risk of hip fracture  in elderly institutionalized women Osteoporosis is a major public health issue leading to significant morbidity , loss of independence and excess loss of life . It has been estimated that 13 to 17 million postmenopausal women have low bone mass or osteoporosis ( 1 , 2 ) . This is associated with almost 1.5 million fractures annually , including 300,000 hip fractures ( 2 , 3 ) . A review of the evidence by Cumming in 1990 ( 4 ) and subsequently published r and omized clinical trials have shown that calcium and /or vitamin D supplements may play a role in the prevention and treatment of osteoporosis by slowing the rates of bone loss in postmenopausal and elderly women ( 5–9 ) . However , there are a limited number of calcium and /or vitamin D trials ( 10–13 ) and observational studies [ review of evidence by Cumming and Nevitt ( 14 ) and Kanis ( 15 ) ] , to support a role for calcium and vitamin D supplementation in the reduction of hip and other fractures . It has also been suggested that calcium and vitamin D supplementation may play a role in the reduction of colorectal cancer incidence ( 16–21 ) . To address these major health concerns of postmenopausal women , the Calcium-Vitamin D ( CaD ) trial of the Women ’s Health Initiative ( WHI ) was design ed to test the primary hypothesis that women who are r and omized to receive calcium and vitamin D supplementation will have a lower risk of hip fracture and secondarily , a lower risk of all fractures and colorectal cancer than women receiving corresponding placebo . The objective of this paper is BACKGROUND Numerous observational studies have found supplemental calcium and vitamin D to be associated with reduced risk of common cancers . However , interventional studies to test this effect are lacking . OBJECTIVE The purpose of this analysis was to determine the efficacy of calcium alone and calcium plus vitamin D in reducing incident cancer risk  of all types . DESIGN This was a 4-y , population -based , double-blind , r and omized placebo-controlled trial . The primary outcome was fracture incidence , and the principal secondary outcome was cancer incidence . The subjects were 1179 community-dwelling women r and omly selected from the population of healthy postmenopausal women aged > 55 y in a 9-county rural area of Nebraska centered at latitude 41.4 degrees N. Subjects were r and omly assigned to receive 1400 - 1500 mg supplemental calcium/d alone ( Ca-only ) , supplemental calcium plus 1100 IU vitamin D3/d ( Ca + D ) , or placebo . RESULTS When analyzed by intention to treat , cancer incidence was lower in the Ca + D women than in the placebo control subjects ( P < 0.03 ) . With the use of logistic regression , the unadjusted relative risks ( RR ) of incident cancer in the Ca + D and Ca-only groups were 0.402 ( P = 0.01 ) and 0.532 ( P = 0.06 ) , respectively . When analysis was confined to cancers diagnosed after the first 12 mo , RR for the Ca + D group fell to 0.232 ( CI : 0.09 , 0.60 ; P < 0.005 ) but did not change significantly for the Ca-only group . In multiple logistic regression models , both treatment and serum 25-hydroxyvitamin D concentrations were significant , independent predictors of cancer risk . CONCLUSIONS Improving calcium and vitamin D nutritional status substantially reduces  all-cancer risk in postmenopausal women . This trial was registered at clinical trials.gov as NCT00352170 Objective : Vitamin D supplementation may be required for certain subgroups in the United States in whom status and intake are inadequate , but the impact of various doses , and whether calcium administration jointly or independently influences vitamin D metabolite levels , is unclear . Methods : In a pilot chemoprevention trial of biomarkers of risk for colorectal adenoma , we measured the impact of vitamin D supplementation and /or calcium supplementation on plasma vitamin D metabolite concentrations . Ninety-two adult men and women living in the southeastern United States were r and omized to 800 IU vitamin D3 , 2000 mg elemental calcium , both , or placebo daily for 6 months . We examined vitamin D status at baseline and postintervention and compared the change in plasma 25-hydroxyvitamin D ( 25(OH)D ) and 1,25(OH)2D levels by intervention group using general linear models . Results : Eighty-two percent of the study population had insufficient plasma 25(OH)D concentrations ( < 75 nmol/L ) at baseline , with the lowest levels observed among African American participants . Vitamin D supplements , with or without calcium supplementation , raised plasma 25(OH)D concentrations , on average , by 25 to 26 nmol/L. Half of the study participants were classified as having sufficient 25(OH)D status after 6 months of 800 IU of vitamin D3 daily . Calcium alone did not influence 25(OH)D concentrations . Conclusion : In this southeastern U.S. population , half of the study participants receiving 800 IU vitamin D3 daily had blood 25(OH)D concentrations of ≤75 nmol/L after a 6-month intervention period , supporting higher vitamin D dose requirements estimated by some groups . More research is needed to identify the optimal vitamin D dose to improve 25(OH)D status in various at-risk population Although vitamin D supplementation in the frail elderly improves calcium absorption , suppresses parathyroid hormone , decreases bone loss and reduces the risk of fractures , such treatment may be ineffective in patients with vertebral osteoporosis , because of impaired vitamin D metabolism or resistance to the action of vitamin D metabolites on the bowel . We have therefore performed a r and omized , single masked study comparing the effects of alfacalcidol treatment ( 0.25 µg twice daily ) and vitamin D2 supplementation ( 500 - 1000 units daily ) on calcium absorption and bone turnover in 46 elderly women ( median age 69 years , range 64–79 years ) with radiological evidence of vertebral fractures .  Serum 25-hydroxyvitamin D increased significantly after 3 and 6 months of treatment with vitamin D2 ( p<0.001 ) , but was unchanged in the group receiving alfacalcidol  . Serum 1,25-dihydroxyvitamin D did not change significantly in either group over the study period . Fractional45Ca absorption increased after 3 months of treatment with alfacalcidol ( p<0.05 ) , but was unchanged with vitamin D2 . There was also a reduction in plasma intact parathyroid hormone and serum alkaline phosphatase after 6 months of treatment with alfacalcidol ( p<0.05 ) which was not seen in the group receiving vitamin D2 . Our study shows that vitamin D2 supplementation is ineffective in stimulating calcium absorption in elderly women with vertebral osteoporosis . By increasing calcium absorption in such patients , alfacalcidol may prove more effective than vitamin D in the management of vertebral osteoporosis Summary On September 29 , 2011 , acknowledged experts in the field of vitamin D , mainly European , were brought together in order to discuss the recent scientific advances in relation to vitamin D : the current requirements and associations with various health outcomes . In this article , the discussion s result ing from the meeting are summarized . Introduction Several groups at risk for developing vitamin D insufficiency have been identified . Accordingly , review s indicate that a significant percentage of the population worldwide have serum 25-hydroxyvitamin D levels below 50 nmol/l . In addition to the role of vitamin D in bone health , recent studies suggest that it may play a pivotal role in other systems , e.g. , the cardiovascular system , pancreas , muscle , immune system and brain . Most evidence , however , is obtained from observational studies and yet inconclusive . Methods To exchange and broaden knowledge on the requirements for vitamin D and its effect on various health outcomes , a workshop entitled “ Vitamin D Expert Meeting : Do we get enough ? ” , was organized . Results Despite low vitamin D levels worldwide , consensus on the definition of deficiency is not yet reached . In order to define cut-off points for vitamin D whilst taking into account extraskeletal health effects , r and omized controlled trials in these fields are warranted . The experts do emphasize that there is evidence to suggest an important role for vitamin D in the maintenance of optimal bone health at all ages and that vitamin D supplementation , in most studies co-administered with calcium , reduces fracture risk in the senior population . Conclusion To reach a serum 25-hydroxyvitamin D level of 50 nmol/l older adults aged ≥65 years are therefore recommended to meet a mean daily vitamin D intake of 20 μg ( 800 IU ) , which is best achieved with a supplement Context Vitamin D supplementation may help prevent fractures , but the relationship between blood vitamin D concentrations and fracture risk is unclear . Contribution These authors observed an increased risk for hip fracture among women with lower serum 25-hydroxyvitamin D [ 25(OH ) vitamin D ] concentrations that was independent of measures of frailty , body mass index , physical function , and falls . Caution The authors did not measure bone mineral density ( BMD ) , so they could not determine whether 25(OH ) vitamin D concentrations give different information about fracture risk than that offered by BMD . Implication Low serum 25(OH ) vitamin D concentrations seem to be associated with a higher hip fracture risk . The Editors Vitamin  D deficiency is common in older adults , especially during the winter ( 1 ) and in homebound population s ( 2 ) , general medical in patients ( 3 ) , and community-dwelling women admitted to the hospital with acute hip fracture ( 4 ) . A recently published evidence -based report on vitamin D and bone health ( 5 ) found the level of evidence for an association between serum 25-hydroxyvitamin D [ 25(OH ) vitamin D ] concentrations and fracture risk to be inconsistent ( 5 ) . Since publication of that review , 1 prospect i ve study ( 6 ) reported no relationship between serum 25(OH ) vitamin D concentrations and fractures , whereas another ( 7 ) reported a significantly lower risk for hip fracture with 25(OH ) vitamin D concentrations greater than 60 nmol/L. Vitamin D concentration could be associated with fractures in several ways . It could influence muscle strength and balance , both of which contribute to falls and disability ( 810 ) . The association between 25(OH ) vitamin D concentrations and fracture may also be influenced by renal function , because renal insufficiency has been linked to fracture ( 11 ) and to vitamin D deficiency ( 12 ) . Several interactions between vitamin D and estrogen receptors have been described ( 13 ) ; hormone therapy has been shown to reverse abnormalities in vitamin D metabolism ( 14 ) , and low vitamin D concentrations have also been linked to higher bone turnover ( 15 , 16 ) . Thus , sex-steroid hormones and bone turnover could contribute to the association between 25(OH ) vitamin D concentration and fractures . We conducted a nested casecontrol study within the WHI-OS ( Women 's Health Initiative Observational Study ) among 400 case- patients with adjudicated incident hip fracture and 400 control participants . We tested whether low serum 25(OH ) vitamin D concentrations are associated with a higher risk for hip fractures in community-dwelling women and whether this relationship may be mediated by poor physical functioning , frailty , falls , sex-steroid hormones , renal function , or bone turnover . Methods Study Population Our study population came from the WHI-OS , a prospect i ve cohort study that enrolled 93676 women between 1994 and 1998 at 40 U.S. clinical centers ( age range , 50 to 79 years ) . Study methods are described in detail elsewhere ( 17 ) . In brief , women were eligible if they were postmenopausal , were unlikely to move or die within 3 years , were not enrolled in the WHI clinical trials , and were not currently participating in any other clinical trial . The human subjects review committees from each participating institution approved the study . Follow-up and Outcome Ascertainment We sent women question naires annually to report any hospitalization and other outcomes , including fractures . As of August 2004 , median follow-up duration was 7.1 years ( range , 0.7 to 9.3 years ) . At that time , 3.7 % of participants had withdrawn or were lost to follow-up and 5.3 % had died . We review ed medical records to verify cases of hip fracture , and blinded central adjudicators confirmed the cases ( 18 ) . We excluded patients with pathologic hip fractures . Nested CaseControl Study Design The present study is a casecontrol study nested within the prospect i ve design of WHI-OS . We excluded women who had a history of hip fracture ; were receiving hormone therapy up to 1 year before enrollment ; or were currently receiving and rogens , selective estrogen receptor modulators , antiestrogens , or other osteoporosis treatments ( bisphosphonates , calcitonin , or parathyroid hormone ) . We also excluded women with insufficient serum stored or of unknown ethnicity , leaving 39793 eligible participants . Of these , 404 women had a hip fracture . We r and omly selected 400 of these women to form the incident hip fracture group . For each case-patient , we selected 1 control participant who was within 1 year of the case-patient 's age at screening , was of matching race or ethnicity , and had their blood drawn within 120 days of the case-patient 's blood draw date ; 99 % of case- patients and control participants were matched within 30 days . Baseline Clinical Variables We divided clinical centers into 3 geographic regions on the basis of latitude : northern ( > 40 N ) , middle ( 35 to 40 N ) , and southern ( < 35 N ) . We ascertained all covariates at baseline . Clinic interviewers recorded current use of prescription medications by direct inspection of medicine containers . We entered prescription names into the WHI data base and assigned drug codes by using Medispan software ( First Data Bank , San Bruno , California ) . Average amounts of elemental calcium and vitamin D preparations were entered directly from supplement containers . Dietary intakes of calcium and vitamin D were assessed by using a semiquantitative food-frequency question naire ( 19 ) . Total calcium and vitamin D intake was defined as the sum of diet and supplements . We used question naires to ascertain date of birth , race or ethnicity , age at menopause , history of any fracture after age 55 years , smoking , parental history of hip fracture , self-rated health status , and alcohol consumption . We classfied physical activity on the basis of frequency and duration of walking and mild , moderate , and strenuous activities in the previous week . We calculated kilocalories of energy expended in 1 week as the metabolic equivalent ( kcal hours/week per kg ) ( 20 ) . We measured physical function by using the R AND Short Form-36 physical function scale , which comprises 10 items measuring whether health now limits physical function in moderate or vigorous activity ( 2 items ) ; strength to lift , carry , stoop , bend , or stair climb ( 4 items ) ; ability to walk various distances without difficulty ( 3 items ) ; and self-care ( 1 item ) ( 21 ) . The scale is scored from 0 to 100 , with higher scores indicating better physical function . We compared women with a score greater than 90 versus those with a score less than or equal to 90 , a cutoff value corresponding to the median score . We computed a frailty score , which included self-reported muscle weakness and impaired walking speed ( R AND Short Form-36 physical function scale score < 75 ) , exhaustion ( R AND Short Form-36 vitality scale score < 55 ) , low physical activity ( lowest quartile of physical activity ) , and unintended weight loss between baseline and 3 years of follow-up ( 22 ) . A woman was considered frail if she reported 3 or more of these indicators . Weight was measured on a balance-beam scale with the participant dressed in indoor clothing without shoes . Height was measured by using a wall-mounted stadiometer . Body mass index was calculated as weight ( in kg ) divided by height ( in m2 ) . Laboratory Procedures Laboratory personnel blinded to casecontrol status obtained a 12-hour fasting blood sample at the baseline visit , which was processed and stored at 80C according to strict quality control procedures ( 23 ) . Serum 25(OH ) vitamin D concentrations and sex-steroid hormone levels were measured at the Reproductive Endocrine Research Laboratory at the University of Southern California .  25-Hydroxyvitamin vitamin D was measured by using a radioimmunoassay with DiaSorin reagents ( DiaSorin , Stillwater , Minnesota ) . The sensitivity of the assay was 3.75 nmol/L. The interassay coefficients of variation were 11.7 % , 10.5 % , 8.6 % , and 12.5 % at 14.0 , 56.8 , 82.5 , and 122.5 nmol/L , respectively . Estradiol and testosterone concentrations were quantified by using sensitive and specific radioimmunoassays after organic solvent extraction and celite column partition chromatography ( 2427 ) . The intra- and interassay coefficients of variation were 7.9 % and 8 % to 12 % , respectively , for estradiol and 6 % and 10 % to 12 % , respectively , for testosterone . We calculated bioavailable hormone concentrations by using mass action equations ( 2830 ) . We measured sex hormonebinding globulin by using a solid-phase , 2-site chemiluminescent immunoassay . The intra- and interassay coefficients of variation were 4.1 % to 7.7 % and 5.8 % to 13 % , respectively . Serum cystatin C , a marker of renal function that is independent of age and weight , was measured at Medical Research Laboratories International , Highl and Heights , Kentucky , by using the Dade Behring BN-II nephelometer and Dade Behring reagents ( Dade Behring , Ramsey , Minnesota ) in a particle-enhanced immunonepholometric assay . Serum C-terminal telopeptide of type I collagen and aminoterminal procollagen extensions propeptide were measured by immunoassay ( Synarc , Lyon , France ) . Statistical Analysis We used chi-square and t tests to compare baseline characteristics between case- patients with hip fracture and matched control participants . We assigned 25(OH ) vitamin D concentrations to quartile categories defined on the basis of the distribution in the control participants . To further assess confounding , we compared baseline characteristics across quartiles of 25(OH ) vitamin D concentrations in case- patients and control participants combined . We calculated the P values for trend by using logistic regression and coding the variable of interest as a continuous variable . We assessed the association between serum 25(OH ) vitamin D concentrations and incident hip fracture in conditional logistic regression models that retained the matched casecontrol design . We first examined the unadjusted associations and then adjusted for age , CONTEXT Serum 25-hydroxyvitamin D ( 25OHD ) concentrations greater than 30 ng/ml have been recommended for lowering fracture risk . OBJECTIVE Our objective was to determine whether 25OHD sufficiency is a prerequisite for effective response to teriparatide ( TPTD ) . DESIGN AND PATIENTS Data were from 1620 osteoporotic postmenopausal women in the Fracture Prevention Trial . The response to TPTD was assessed in women subgrouped by having 25OHD insufficiency ( > 10 but < or=30 ng/ml ) or 25OHD sufficiency ( > 30 but < or=183 ng/ml ) at the baseline ( r and omization ) visit . An abnormal intact PTH was exclusionary . INTERVENTIONS At baseline , after at least 1 month of supplementation with calcium ( 1000 mg ) and vitamin D ( 400 - 1200 IU ) daily , women were r and omized to placebo or 20 or 40 microg TPTD by daily sc injection for a median of 19 months . Observation was for a median of 21 months . MAIN OUTCOME MEASURES Main outcome measures included vertebral and nonvertebral fractures , change in bone mineral density at the lumbar spine and femoral neck , change in bone formation marker amino-terminal extension peptide of procollagen type 1 , and the proportion of women with serum calcium at least 2.76 mmol/liter 4 - 6 h after dosing . RESULTS TPTD  reduced vertebral and nonvertebral fracture risk , increased lumbar spine and femoral neck bone mineral density , and increased amino-terminal extension peptide of procollagen type 1 relative to placebo in the two 25OHD subgroups . There were no significant differences in these endpoints between the subgroups ( each treatment by subgroup interaction , P > 0.10 ) . However , it should be noted that because of the limited number of fractures , this study does not exclude the possibility of differences in fracture outcome between the subgroups . CONCLUSIONS In postmenopausal women with osteoporosis and normal intact PTH , the responses to TPTD did not differ significantly in women with baseline 25OHD insufficiency or sufficiency BACKGROUND Adults with low concentrations of 25-hydroxyvitamin D ( 25[OH]D ) in blood have an increased risk of falls and fractures , but r and omised trials of vitamin D supplementation have had inconsistent results . We aim ed to assess the effect of high-dose vitamin D supplementation on fractures and falls . METHODS The Vitamin D Assessment ( ViDA ) Study was a r and omised , double-blind , placebo-controlled trial of healthy volunteers aged 50 - 84 years conducted at one centre in Auckl and , New Zeal and . Participants were r and omly assigned to receive either an initial oral dose of 200 000 IU ( 5·0 mg ) colecalciferol ( vitamin D3 ) followed by monthly 100 000 IU ( 2·5 mg ) colecalciferol or equivalent placebo dosing . The prespecified primary outcome was cardiovascular disease and secondary outcomes were respiratory illness and fractures . Here , we report secondary outcome data for fractures and post-hoc outcome data for falls . Cox proportional hazards models were used to estimate hazard ratios ( HRs ) for time to first fracture or time to first fall in individuals allocated vitamin D compared with placebo . The analysis of fractures included all participants who gave consent and was by intention-to-treat ; the analysis of falls included all individuals who returned one or more question naires . This trial is registered with the Australian New Zeal and Clinical Trials Registry , number ACTRN12611000402943 . FINDINGS Between April 5 , 2011 , and Nov 6 , 2012 , 5110 participants were recruited and r and omly assigned either colecalciferol ( n=2558 ) or placebo ( n=2552 ) . Two participants allocated placebo withdrew consent after r and omisation ; thus , a total of 5108 individuals were included in the analysis of fractures . The mean age of participants was 65·9 years ( SD 8·3 ) and 2971 ( 58 % ) were men . The mean concentration of 25(OH)D in blood was 63 nmol/L ( SD 24 ) at baseline , with 1534 ( 30 % ) having 25(OH)D concentrations lower than 50 nmol/L. Follow-up was until July 31 , 2015 , with a mean treatment duration of 3·4 years ( SD 0·4 , range 2·5 - 4·2 ) . During follow-up , 2638 participants reported having a fall , 1312 ( 52 % ) of 2539 in the vitamin D group compared with 1326 ( 53 % ) of 2517 in the placebo group . The HR for falls-adjusted for age , sex , ethnic origin , history of recent fall , physical activity , and baseline 25(OH)D-was 0·99 ( 95 % CI 0·92 - 1·07 ; p=0·82 ) for vitamin D compared with placebo . Non-vertebral fractures were reported in 292 individuals , 156 ( 6 % ) of 2558 in the vitamin D group and 136 ( 5 % ) of 2550 in the placebo group . The adjusted HR for fractures was 1·19 ( 95 % CI 0·94 - 1·50 ; p=0·15 ) for vitamin D compared with placebo . 123 ( 2 % ) people died  during the trial , 65 assigned vitamin D and 58 allocated placebo ; the difference between treatment groups was not significant . INTERPRETATION High-dose bolus vitamin D supplementation of 100 000 IU colecalciferol monthly over 2·5 - 4·2 years did not prevent falls or fractures in this healthy , ambulatory , adult population . Further research is needed to ascertain the effects of daily vitamin D dosing , with or without calcium . FUNDING Health Research Council of New Zeal and and Accident Compensation Corporation of New Zeal and
Conclusions and Relevance In this systematic review and meta- analysis , neither intermittent nor daily dosing with st and ard doses of vitamin D alone was associated with reduced risk of fracture , but daily supplementation with both vitamin D and calcium was a more promising strategy
Importance Vitamin D and calcium supplements are recommended for the prevention of fracture , but previous r and omized clinical trials ( RCTs ) have reported conflicting results , with uncertainty about optimal doses and regimens for supplementation and their overall effectiveness .
Objective To assess the risks of fracture associated with differences in concentrations of 25-hydroxyvitamin D ( 25[OH]D ) in observational studies and the risks of fracture associated with supplementation with vitamin D alone or in combination with calcium in RCTs .