title: Effects of vitamin D and calcium supplementation on falls: a randomized controlled trial.
abstract: Specific receptors for vitamin D have been identified in human muscle tissue. Cross-sectional studies show that elderly persons with higher vitamin D serum levels have increased muscle strength and a lower number of falls. We hypothesized that vitamin D and calcium supplementation would improve musculoskeletal function and decrease falls. In a double-blind randomized controlled trial, we studied 122 elderly women (mean age, 85.3 years; range, 63-99 years) in long-stay geriatric care. Participants received 1200 mg calcium plus 800 IU cholecalciferol (Cal+D-group; n = 62) or 1200 mg calcium (Cal-group; n = 60) per day over a 12-week treatment period. The number of falls per person (0, 1, 2-5, 6-7, >7 falls) was compared between the treatment groups. In an intention to treat analysis, a Poisson regression model was used to compare falls after controlling for age, number of falls in a 6-week pretreatment period, and baseline 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D serum concentrations. Among fallers in the treatment period, crude excessive fall rate (treatment - pretreatment falls) was compared between treatment groups. Change in musculoskeletal function (summed score of knee flexor and extensor strength, grip strength, and the timed up&go test) was measured as a secondary outcome. Among subjects in the Cal+D-group, there were significant increases in median serum 25-hydroxyvitamin D (+71%) and 1,25-dihydroxyvitamin D (+8%). Before treatment, mean observed number of falls per person per week was 0.059 in the Cal+D-group and 0.056 in the Cal-group. In the 12-week treatment period, mean number of falls per person per week was 0.034 in the Cal+D-group and 0.076 in the Cal-group. After adjustment, Cal+D-treatment accounted for a 49% reduction of falls (95% CI, 14-71%; p < 0.01) based on the fall categories stated above. Among fallers of the treatment period, the crude average number of excessive falls was significantly higher in the Cal-group (p = 0.045). Musculoskeletal function improved significantly in the Cal+D-group (p = 0.0094). A single intervention with vitamin D plus calcium over a 3-month period reduced the risk of falling by 49% compared with calcium alone. Over this short-term intervention, recurrent fallers seem to benefit most by the treatment. The impact of vitamin D on falls might be explained by the observed improvement in musculoskeletal function.
authors.affiliation: Department of Orthopaedics, University of Basel, Basel, Switzerland. hbischof@hsph.harvard.edu
authors.forename: Heike A
authors.initials: HA
authors.lastname: Bischoff
authors.forename: Hannes B
authors.initials: HB
authors.lastname: Stähelin
authors.forename: Walter
authors.initials: W
authors.lastname: Dick
authors.forename: Regula
authors.initials: R
authors.lastname: Akos
authors.forename: Margrith
authors.initials: M
authors.lastname: Knecht
authors.forename: Christian
authors.initials: C
authors.lastname: Salis
authors.forename: Matthias
authors.initials: M
authors.lastname: Nebiker
authors.forename: Robert
authors.initials: R
authors.lastname: Theiler
authors.forename: Michael
authors.initials: M
authors.lastname: Pfeifer
authors.forename: Bettina
authors.initials: B
authors.lastname: Begerow
authors.forename: Robert A
authors.initials: RA
authors.lastname: Lew
authors.forename: Martin
authors.initials: M
authors.lastname: Conzelmann
mesh_terms: D000058:Accidental Falls / Q000517:prevention & control*; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001842:Bone and Bones / Q000378:metabolism; D002112:Calcifediol / Q000378:metabolism; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology*; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D050723:Fractures, Bone / Q000517:prevention & control*; D006801:Humans; D008875:Middle Aged; D009132:Muscles / Q000378:metabolism; D016012:Poisson Distribution; D013997:Time Factors; D014807:Vitamin D / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D014807:Vitamin D; D002112:Calcifediol; D002118:Calcium