Vitamin D Supplement Intake in Elderly Fallers

To the Editor: Approximately 30% of ambulatory older adults fall yearly;1 5% to 10% are seriously injured.2 Vitamin D deficiency increases body sway and decreases muscle mass and strength, increasing falls risk.3,4 Vitamin D supplementation reduces falls by 11% to 22%.5,6 To our knowledge, no studies have been conducted that report characteristics of ambulatory fallers associated with meeting the recommended adequate intake (RAI) of vitamin D. Patient characteristics associated with vitamin D intake in a falls study are reported. Data were analyzed from Safety Assessment for Elders (SAFE), a randomized, controlled study of multifactorial interventions to reduce falls (ClinicalTrials.org identifier NCT00140322). Eligible subjects were adults aged 65 and older at high falls risk.7 At baseline and study end, researchers visited subjects' homes to examine all medication and supplement bottles and record vitamin D intake. Participants were randomized to receive mailed home safety information or a multifactorial intervention designed to decrease falls risk. In the active arm, subjects with a daily vitamin D intake less than 800 IU were asked to increase intake to ≥800 IU per day.8 Participants and their physicians received letters instructing them how to increase vitamin D intake. Participants were called monthly for 11 months to encourage adherence with recommendations. Study outcomes were the rates and patient characteristics (Table 1) associated with meeting the age-specific vitamin D RAI of 400 IU per day for people aged 51 to 70 or 600 IU per day for people aged 71 and older9 at study entry and study end. Subjects with unknown vitamin D intake at baseline (n=18 of 500) were excluded. Forty-five of 482 subjects had missing data at 1 year; these individuals were similar to the remaining subjects (P>.05, candidate variables). All data were analyzed using Analyze-It software (Leeds, UK) and summarized using means±standard deviations or percentages. Continuous study data were parametric, allowing analysis using independent sample t-tests. Chi-square tests examined proportions. In all cases, two-sided P<.05 determined significant findings. Vitamin D intake was recorded at baseline (n=482) and study end (n=446) from 500 subjects enrolled. Baseline demographics (Table 1) included a mean age±standard deviation of 79±8 and a predominance of female (75%) and Caucasian (97%) subjects. Participants reported an average of three falls yearly and a mean vitamin D supplement intake of 370±320 IU daily. Only 28% of subjects met the vitamin D RAI at study entry, increasing to 37% at study end (P=.007). Five characteristics were associated with greater likelihood of meeting the age-specific vitamin D RAI at baseline (Table 1). Participants meeting the RAI (n=135) were younger (76±8 vs 80±7, P<.001); had better physical function scores (41±11 vs 39±10, P=.04); and were more likely to be female (87 vs 70%, P=.003), to have had a prior fracture (47% vs 37%, P=.05), and to take calcium supplements (94 vs 57%, P<.001). Subjects with known vitamin D intake at entry and study end (n=437) increased vitamin D intake during the study (350±300 IU/d to 410±350 IU/d, P=.009). Subjects randomized to active falls interventions (33 vs 17%, P<.001) and those reporting regular exercise (2 vs 20%, P=.04) were statistically more likely to increase vitamin D intake during the 1-year study. Vitamin D is a safe, inexpensive strategy to reduce falls and associated medical costs. This study showed that older fallers have a low rate of meeting the vitamin D RAI, especially men, older individuals, those without prior fracture, and those not taking calcium supplements. Patients and providers need greater education on the importance of vitamin D for prevention of falls and fractures. Written instructions and regular telephone follow-up appear to increase vitamin D intake in elderly fallers. This finding, if verified in additional studies, may prove an effective public health strategy to decrease falls in older adults. Conflict of Interest: The editor in chief has reviewed the conflict of interest checklist provided by the authors and has determined that the authors have no financial or any other kind of personal conflicts with this letter. Support was received from the Centers for Disease Control and Prevention (CDC PA-02151). Author Contributions: Kiehn and Jones: Data entry, data analysis, manuscript composition. Mahoney: Study design, subject recruitment, data collection, manuscript revision. Hansen: Data entry, data analysis, manuscript composition. Sponsor's Role: The sponsor had no role in the design, methods, subject recruitment, data collections, analysis and preparation of this letter.