Each year, one third of adults 65 years and older have at least one fall. And, 9% of those falls require an emergency department visit and up to 6%result in a fracture. Consequently, strategies to prevent falls have become an important public health goal for the elderly.
A recent review of multiple published studies concluded that vitamin D supplementation taken in dosages of 700 to 1,000 IU per day (achieving a serum 25-hydroxyvitamin D level of at least 24) reduces falls in older persons by 26%.
And, for good news for the cost conscious, the more expensive active forms of vitamin D (which also had double the rate of a significant side effect) were no more effective than the very inexpensive and safer over-the-counter supplemental vitamin D.
A vitamin D level (as a blood test) is inexpensive, and treating a low vitamin D level even more inexpensive.
Some studies of vitamin D supplementation in older adults have shown improved strength, function, and balance in addition to reduced falls. Other studies have not found any benefit, which may be attributed to differences in dosing and the use of open trial designs.
Vitamin D is now available as an over-the-counter supplement (vitamin D3 or vitamin D2), or in an active form (1α-hydroxyvitamin D3 or 1,25-dihydroxyvitamin D3). So, researcher Bischoff-Ferrari and colleagues conducted a meta-analysis to determine the effectiveness of various vitamin D formulations on the prevention of falls in older persons.
The authors evaluated articles from 1991 to 2008, highlighting randomized, double-blind, controlled clinical trials of fall prevention using defined dosages and types of vitamin D in adults 65 years and older. The primary outcome was the risk of at least one fall while on vitamin D supplementation, with or without calcium, compared with persons on placebo or on calcium alone.
Of 164 articles identified, 10 were included in the final analysis; five trials used vitamin D3, three used vitamin D2, and two studied active forms of vitamin D.
Of the 2,426 participants in the eight trials of vitamin D2 or D3, the average age was 80 years, and 81% were women. All participants were in stable health and were living in the community or in nursing homes.
Daily dosages ranged from 200 IU to 1,000 IU during a treatment course of two to 36 months. Calcium supplementation (500 to 1,200 mg per day) was used in both the treatment and placebo arms in five trials, was used only in the treatment group of one trial, and was not used in two studies (vitamin D compared with placebo). In seven of the eight trials, the rate of adherence was reported to be 80 to 100 percent.
Among the seven high-dose trials (i.e., those that used 700 to 1,000 IU of supplemental vitamin D per day), dose stratification showed that daily dosages of 700 IU or more resulted in a relative risk reduction of 19%.
Subgroup analysis of the trials using high-dose vitamin D3 showed a fall reduction of 26%.
For all supplemental vitamin D, the number needed to treat was 11 for two to 36 months to achieve significant fall reduction.
Dosages of less than 700 IU per day did not confer any benefit in reducing falls.
Serum 25-hydroxyvitamin D levels of 24 ng per mL (60 nmol per L) or more were associated with a 23 percent reduction in falls. And, in a subgroup analysis of the high-dose trials, there were no significant differences among participants who used calcium supplementation and those who did not.
Finally, the two studies using the active forms of vitamin D showed a relative risk reduction similar to that of the supplemental forms, but had twice the hypercalcemia rate compared with placebo.
SOURCE: Bischoff-Ferrari  HA, et al.  Fall prevention with supplemental and active forms of vitamin D: a meta-analysis of randomised controlled trials. BMJ. October  1, 2009;339:b3692.