Vitamin D’s Impact on Falls

By Maura Keller

Older patients can reduce their risk of falling by consuming the Recommended Daily Allowance of vitamin D.

It should come as no surprise that falls are the leading cause of serious injuries in older patients. According to the American Geriatrics Society, each year about one third of Americans aged 65 and older fall, leading to hospitalizations, admissions into long-term care facilities, and even death.

And while many health problems, including arthritis, poor balance, muscle weakness, poor vision, dementia, and certain medications may increase fall risk, vitamin D deficiency plays a surprising role in older adults’ falls.

The Vitamin D Connection

Carbohydrates are good. Carbohydrates are bad. You should eat more protein. You should eat less protein. The less fat you have in your diet, the better. Your body needs a certain amount of fat to function properly.

It seems the guidelines for a healthful diet and lifestyle change almost daily. It can be difficult for your patients to keep up with the latest theories and even more difficult for them to know who to believe in light of conflicting advice.

But one thing is certain: Vitamin D appears to reduce the risk of falls in older adults by improving muscle function and strength. So consuming the Recommended Daily Allowance of vitamin D can reduce their risk of falling.  

Here’s why. “Vitamin D regulates calcium transport into muscle cells, which is necessary for muscle contraction,” says Denise Houston, PhD, RD, of the Sticht Center on Aging in the department of internal medicine section on gerontology and geriatric medicine at Wake Forest University School of Medicine. “Vitamin D also plays a role in regulating protein synthesis within muscle cells, which is necessary for building and repairing muscle fibers. Observational studies show that individuals with low vitamin D levels are more likely to have worse physical function, for example, slower gait and worse physical performance and balance, as well as lower strength.”

According to Elizabeth Sykes, MD, vice chief of clinical pathology at Beaumont Hospital in Royal Oak, Mich., older adults with vitamin D deficiency also have an increased risk of muscle weakness and bone diseases such as osteomalacia (softening of the bones) or osteoporosis (reduced bone density) as well as an increased risk of rheumatoid arthritis and type 1 diabetes.  
  
In addition to individuals with limited sun exposure, older patients and people with dark skin color, who have difficulty digesting or absorbing nutrients from food, patients with chronic kidney disease, those who are obese, or individuals who are taking steroids are at highest risk of developing a vitamin D deficiency.

“Older adults with limited sun exposure, for example, home-bound or institutionalized, as well as those with inadequate vitamin D in their diet are at greater risk of low vitamin D levels,” Houston says. “Few foods contain vitamin D naturally, for example, fatty fish such as salmon, tuna, and mackerel. Vitamin D-fortified milk provides most of the vitamin D in the diet in the U.S. [at] 100 IU per 8-oz glass.”

And while limited exposure to vitamin D is cause for concern, some older adults may be unable to properly absorb vitamin D. “Vitamin D is a fat-soluble vitamin. If an individual has problems with fat malabsorption, they cannot absorb vitamin D adequately,” Sykes says.

“Low levels of vitamin D are an increased risk for both falls and fractures, and supplementing with vitamin D is shown to significantly reduce the risk of both,” says Kent Holtorf, MD, founder of Holtorf Medical Group, one of the largest private physician groups in the country. “Studies clearly show that vitamin D supplementation can prevent falls. Other supplements are shown to be of benefit as well, including B vitamins and antioxidants.”

Treatment Options

If older patients have inadequate vitamin D levels from either lack of sun exposure or improper dietary intake, improving vitamin D levels can be done inexpensively and safely with supplementation. 

According to Houston, serum concentration of 25-hydroxyvitamin D (25(OH)D) is the best indicator of vitamin D status. “While consensus is lacking in what constitutes an adequate 25(OH)D concentration, 30 ng/mL or higher have been suggested by experts in the field as desirable,” Houston says. Circulating 1,25-dihydroxyvitamin D (1,25(OH)2D) is generally not a good indicator of vitamin D status because it has a short half-life; concentrations are closely regulated by parathyroid hormone, calcium, and phosphate; and 1,25(OH)2D concentrations do not typically decrease until vitamin D deficiency is severe.”

So what dosage of vitamin D supplementation is appropriate for most older patients?
“Studies combining results from several randomized controlled trials have shown that individuals taking 700 to 1,000 IU of vitamin D daily have approximately a 20% reduction in falls,” Houston says.

The Institute of Medicine (IOM) recently released its report and vitamin D recommendations. This study assessed current data and updated the Dietary Reference Intakes for vitamin D and calcium. The Food and Nutrition Board of the IOM put together a committee of scientific experts for this review of vitamin D and calcium in January 2009. The expert panel that reviewed the latest science related to vitamin D is made up of experts from both the United States and Canada.

And while vitamin D supplements appear to help older patients to prevent falls, Holtorf says it’s important for healthcare professionals to remember that supplements cannot reverse the deterioration or aging process but can prevent further deterioration and prevent age-related illnesses.

“The medical profession has been focused on treatment after it is too late rather than prevention. They continue to look at ‘normal’ vs. ‘abnormal’ rather than look at ‘optimal’ vs. ‘suboptimal’ levels,” Holtorf says. “Doctors will often not treat until something is abnormal instead of optimizing levels to prevent the illness before it occurs.”

In addition to monitoring vitamin D levels, healthcare professionals should review patients’ medications to see whether any could increase patients’ risk of falling and identify any health problems that may contribute to a higher incidence of falls. The combination of exercise, physical therapy, balance training, medication modification, and vitamin D supplements can help lower older adults’ fall risk and prevent disabling injuries.

— Maura Keller is a Minneapolis-based writer and editor.