That's the finding of Oregon State University researchers who analyzed data from a survey of more than 4,300 U.S. adults older than 60.
Those with low vitamin D levels had a 30 percent greater risk of death during the study period than those with higher levels. Frail people had more than double the risk of death than those who were not frail. And those who were both frail and had low vitamin D levels were three times more likely to die than those who were not frail and had higher vitamin D levels.
The study was published online recently in the European Journal of Clinical Nutrition.
"What this really means is that it is important to assess vitamin D levels in older adults, and especially among people who are frail," lead author and nutritional epidemiologist Ellen Smit said in a university news release. "Older adults need to be screened for vitamin D."
The researchers could not determine whether low vitamin D levels contributed to frailty or if frail people had low vitamin D levels due to health problems, but that may not be important, the researchers said.