Too Little Vitamin D May Hasten Disability as You Age

WEDNESDAY, July 17 (HealthDay News) -- Older people with vitamin D deficiency may struggle with daily physical activities such as dressing or climbing stairs, a new study shows.

It's estimated that as many as 90 percent of older people are vitamin D-deficient. The vitamin, usually absorbed through sunlight or diet, plays a key role in bone and muscle health, and a deficiency can lead to reduced bone density, muscle weakness, osteoporosis and broken bones.

The study included more than 1,300 people, aged 55 to 88, in the Netherlands who were followed for six years. Participants' vitamin D levels were checked and they were asked about their ability to do routine tasks, such as sitting down and standing up from a chair or walking outside for five minutes without resting.

Among participants aged 65 to 88, those with the lowest vitamin D levels were 1.7 times as likely to have at least one physical limitation as those with the highest vitamin D levels. Among participants aged 55 to 65, those with the lowest vitamin D levels were twice as likely to have at least one physical limitation as those with the highest vitamin D levels.

In the older age group, 70 percent of those with the lowest vitamin D levels had at least one physical limitation, while most of those with moderate or high vitamin D levels had no physical limitations, according to the study, published July 17 in the Journal of Clinical Endocrinology & Metabolism.

The researchers also found that people with vitamin D deficiency were more likely to develop additional physical limitations over time. This occurred over three years among people in the older age group and over six years among those in the younger age group.

"Seniors who have low levels of vitamin D are more likely to have mobility limitations and to see their physical functioning decline over time," study author Evelien Sohl, of VU University Medical Center in Amsterdam, said in a journal news release. "Older individuals with these limitations are more likely to be admitted to nursing homes and face a higher risk of mortality."

The findings indicate low vitamin D levels in older individuals may contribute to the declining ability to live independently, Sohl said. "Vitamin D supplementation could provide a way to prevent physical decline, but the idea needs to be explored further with additional studies," she said.

While the study found an association between low vitamin D levels and limited mobility, it did not establish a cause-and-effect relationship.

More information

The Harvard School of Public Health has more about vitamin D and health.

SOURCE: Journal of Clinical Endocrinology & Metabolism, news release, July 17, 2013