BOSTON -- Nursing home residents taking 800 IU of vitamin D were less likely to fall and had a 72% decrease in falls compared with those taking a placebo, according to a five-month study.
BOSTON -- Nursing home residents taking 800 IU of vitamin D were less likely to fall and had a lower rate of falls than those taking a placebo or lower vitamin D doses, researchers reported.
Over five months, those taking 800 IU of vitamin D had a 72% decrease in falls compared with those taking a placebo, according to a randomized multiple-dose study reported in the Journal of the American Geriatric Society.
However, fall rates for vitamin D doses ranging from 200 IU to 600 IU were no different from the placebo-arm rates, said Kerry Broe, M.P.H, of Harvard's Institute for Aging Research, and colleagues.
Past studies have shown that vitamin D supplements can help prevent falls in seniors, but until now, the effective dosage was unknown, the researchers said.
The dosage findings in their report came from a secondary analysis of an earlier randomized clinical trial at a 725-bed long-term care facility (Hebrew Rehabilitation Center for Aged) in Boston.
Participants included 124 individuals (mean age 89; 73% female) who were randomized to one of five vitamin groups: placebo, 200 IU, 400 IU, 600 IU, and 800 IU. The vitamin D tablet used in the study was D2, consistent with the vitamin D found in standard multivitamins.
Of the participants, 63% were taking a daily multivitamin, 54% had low vitamin D concentrations (<20 ng/mL), and 62% had fallen in the previous year. No significant differences were observed between the groups for any variable except age.
Over the five-month study, 61 of 124 (59%) participants had at least one fall, the investigators said, adding that a fall is a predictor of a future fall and the risk of fracture and injury. A fall, marked by an incident report, was defined as a sudden, unintentional change in position causing a resident to fall to the ground.
Of 23 participants in the 800 IU group, only five (20%) had a fall. The adjusted incidence rate ratio of falls over five months compared with placebo was 72% (rate ratio=0.28, 95% confidence interval =0.11-0.75), the researchers reported.
There was no significant difference for the adjusted fall rates compared with placebo in any of these other supplement groups. The proportion of participants with a fall was 44% in the placebo group (11/ 25), 58% (15/26) in the 200 IU group, 60% (15/25) in the 400 IU group, and 60% (15/25) in the 600 IU group.
Recently a panel of vitamin D experts concluded that a minimum serum concentration between 20 and 32 ng/mL would be optimal for bone health, the investigators said. Four of the five experts suggested values between 28 and 32 ng/mL.
Serum measurements at the end of this study for 17 participants taking 800 IU was a mean concentration of 29.95 ng/mL, well within the recommended optimal range, and none had measures below 20 ng/mL.
Reaching these serum concentrations may improve bone health and musculoskeletal function in this elderly population, and this may be a why significant reduction in falling was found only in the 800 IU group, the researchers said. A typical supplement contains 400 IU of vitamin D.
However, the investigators added, falls in nursing homes are mutlifactorial. Ensuring that residents receive adequate vitamin D supplementation represents only one potential part of a fall-prevention program, they emphasized.
Generalizability of the study was limited, the researchers said, because the sample was small and participants were Caucasian and healthier than the other nursing home residents. Replication of these results in a frailer sample of nursing home residents is warranted.
In addition, information was not available on how many residents were approached for this study and were excluded. Also, there may have been unreported falls because minor unwitnessed falls were not reported, they added.
Sounding a note of caution, the investigators said that the effective dose, 800 IU, is higher than the dose typically taken by older persons. Taking 800 IU should be done only with the approval of a patient's physician, and certain conditions, such as high blood calcium levels, need to be considered.
The authors noted that further research is required to accurately determine vitamin D's effect with regard to patients' current health conditions, such as kidney function, and other variables, including ethnicity.
Merely taking vitamin D may not be enough to reduce falls, and all other preventative measures need to be considered, the researchers emphasized.