Vitamin
D + Calcium = Fewer Falls in Senior Women
Healthnotes Newswire (April 20, 2006)—Long-term supplementation
with a vitamin D–calcium combination reduced the risk of
falls in older women, according to the Archives of Internal Medicine
(2006;166:424–30).
Participants were randomly assigned to receive
700 IU per day of vitamin D3 plus 500 mg per day of calcium (as
calcium citrate malate) or placebo for three years. Of the 445
volunteers who began the study, 389 attended the three-year follow-up
visit, and 318 were still taking the supplements. Originally designed
to examine the effect of the vitamin–mineral combination
on bone mineral density, the study also looked at a person’s
risk of falling at least once during the follow-up period.
Supplementing with vitamin D–calcium reduced the odds of
falling by 46% among most women and by as much as 65% in less
active women. This benefit was further enhanced among less active
women who continued to take the supplements for the entire three
years; in that group there was a 74% fall reduction. Although
men did not receive a statistically significant benefit, there
was a trend toward improvement among less active men who stayed
on treatment to the end of the study.
While it is well known that calcium is required for muscle function,
it is not well appreciated that vitamin D is also required for
muscle function. Several studies have indicated a positive association
between blood levels of vitamin D and lower extremity strength
and function in older people. But how could taking a vitamin D
supplement prevent falls? Muscle tissue contains vitamin D receptors
that promote muscle strength and have been shown to decline in
number with age. In fact, muscle weakness—a major risk factor
for falls in the elderly—is a prominent sign of vitamin
D deficiency. In addition, vitamin D plays a role in the normal
functioning of the nervous system, and vitamin D deficiency leads
to poor balance.
The findings fit well with the results of the original study,
which showed a 60% reduction of osteoporotic fractures with vitamin
D–calcium compared with placebo, since many such fractures
result from falling. Consistent with the present study, most of
the fractures occurred in women. The benefits obtained by this
simple, cost-effective intervention are comparable to or greater
than those of more expensive and time-consuming interventions,
such as medication adjustments, occupational therapy, and exercise
programs.