Lower vitamin D could increase risk of dying, especially for frail, older adults

July 26, 2012, Oregon State University
Milk is one of the sources of vitamin D. About 70 percent of Americans, and up to a billion people worldwide, have insufficient levels of vitamin D. Credit: Photo: Theresa Hogue/OSU

A new study concludes that among older adults – especially those who are frail – low levels of vitamin D can mean a much greater risk of death.

The randomized, nationally representative study found that older adults with low levels had a 30 percent greater risk of death than people who had higher levels.

Overall, people who were frail had more than double the risk of death than those who were not frail. Frail adults with low levels of vitamin D tripled their risk of death over people who were not frail and who had higher levels of vitamin D.

"What this really means is that it is important to assess vitamin D levels in older adults, and especially among people who are frail," said lead author Ellen Smit of Oregon State University.

Smit said past studies have separately associated frailty and low vitamin D with a greater mortality risk, but this is the first to look at the combined effect. This study, published online in the European Journal of Clinical Nutrition, examined more than 4,300 adults older than 60 using data from the Third National Health and Nutrition Examination Survey.

"Older adults need to be screened for vitamin D," said Smit, who is a nutritional epidemiologist at OSU's College of Public Health and Human Sciences. Her research is focused on diet, metabolism, and physical activity in relation to both chronic disease and HIV infection.

"As you age, there is an increased risk of melanoma, but older adults should try and get more activity in the sunshine," she said. "Our study suggests that there is an opportunity for intervention with those who are in the pre-frail group, but could live longer, more independent lives if they get proper nutrition and exercise."

Frailty is when a person experiences a decrease in physical functioning characterized by at least three of the following five criteria: muscle weakness, slow walking, exhaustion, low physical activity, and unintentional weight loss. People are considered "pre-frail" when they have one or two of the five criteria.

Because of the cross-sectional nature of the survey, researchers could not determine if low vitamin D contributed to frailty, or whether frail people became vitamin D deficient because of health problems. However, Smit said the longitudinal analysis on death showed it may not matter which came first.

"If you have both, it may not really matter which came first because you are worse off and at greater risk of dying than other older people who are frail and who don't have low vitamin D," she said. "This is an important finding because we already know there is a biological basis for this. Vitamin D impacts muscle function and bones, so it makes sense that it plays a big role in frailty."

The study divided people into four groups. The low group had levels less than 50 nanograms per milliliter; the highest group had vitamin D of 84 or higher. In general, those who had lower vitamin D levels were more likely to be frail.

About 70 percent of Americans, and up to a billion people worldwide, have insufficient levels of vitamin D. And during the winter months in northern climates, it can be difficult to get enough just from the sun. OSU's Linus Pauling Institute recommends adults take 2,000 IU of supplemental vitamin D daily. The current federal guidelines are 600 IU for most adults, and 800 for those older than 70.

"We want the older population to be able to live as independent for as long as possible, and those who are frail have a number of health problems as they age," Smit said. "A balanced diet including good sources of vitamin D like milk and fish, and being physically active outdoors, will go a long way in helping to stay independent and healthy for longer."

Explore further: Older adults may need more vitamin D to prevent mobility difficulties

Related Stories

Older adults may need more vitamin D to prevent mobility difficulties

May 29, 2012
Older adults who don't get enough vitamin D – either from diet, supplements or sun exposure – may be at increased risk of developing mobility limitations and disability, according to new research from Wake Forest ...

Vitamin D deficiency linked to higher mortality in female nursing home residents

March 6, 2012
The majority of institutionalized elderly female patients are vitamin D deficient and there is an inverse association of vitamin D deficiency and mortality, according to a recent study accepted for publication in The Endocrine ...

Low vitamin D levels linked to weight gain in some older women

June 25, 2012
Older women with insufficient levels of Vitamin D gained more weight than those with sufficient levels of the vitamin, according to a new study funded by the National Institutes of Health and published online in the Journal ...

Recommended for you

Women run faster after taking newly developed supplement, study finds

January 19, 2018
A new study found that women who took a specially prepared blend of minerals and nutrients for a month saw their 3-mile run times drop by almost a minute.

Americans are getting more sleep

January 19, 2018
Although more than one in three Americans still don't get enough sleep, a new analysis shows first signs of success in the fight for more shut eye. According to data from 181,335 respondents aged 15 and older who participated ...

Wine is good for you—to a point

January 18, 2018
The Mediterranean diet has become synonymous with healthy eating, but there's one thing in it that stands out: It's cool to drink wine.

Sleep better, lose weight?

January 17, 2018
(HealthDay)—Sleeplessness could cost you when it's time to stand on your bathroom scale, a new British study suggests.

Who uses phone apps to track sleep habits? Mostly the healthy and wealthy in US

January 16, 2018
The profile of most Americans who use popular mobile phone apps that track sleep habits is that they are relatively affluent, claim to eat well, and say they are in good health, even if some of them tend to smoke.

Improvements in mortality rates are slowed by rise in obesity in the United States

January 15, 2018
With countless medical advances and efforts to curb smoking, one might expect that life expectancy in the United States would improve. Yet according to recent studies, there's been a reduction in the rate of improvement in ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.