Higher Vitamin D, Better Golden Years?
Older Adults With Higher Vitamin D Levels Have Improved Mobility, Study Finds
Vitamin D Levels and Physical Functioning
"Over time, everybody declined in the tasks, as expected," Houston says.
However, those who started out with higher vitamin D did better on the tests than those whose vitamin D levels were lower at the start. "People who had higher levels started out with better physical functioning and because they started out better, they remained at higher physical functioning,'' Houston says.
''Those with adequate or optimal vitamin D status [the highest group] had approximately 5% higher physical performance scores and 5% faster walk speed on the 400-meter walk compared to those with insufficient vitamin D status at the 4-year follow up," she says.
Next, Houston wants to focus on whether vitamin D blood levels can predict disability in older adults and whether supplements can ward off disability and mobility problems.
Vitamin D Levels and Mobility: Second View
The study results aren't surprising to Erica T. Goode, MD, MPH, a physician at the California Pacific Medical Center's Health & Healing Center-Clinic in San Francisco, who was attending the meeting.
''I'm sure that this is accurate," she says of the finding that those adults with higher vitamin D levels performed better on the physical functioning tests.
Vitamin D: How Much Is Enough?
Exactly how much vitamin D is enough for older adults (and others, as well) is a matter of ongoing debate.
According to the Institute of Medicine, an adequate intake is 400 international units (IU) for adults 51 to 70 and 600 IU for people older than 70. A level of 2,000 IU is considered the ''upper tolerable limit" by the IOM.
But some nutrition scientists have challenged those recommendations, contending that up to 10,000 IU a day of the vitamin is generally safe.
''By all means, try to get at least 1,000 IU,'' Goode says.
The IOM is reviewing the data and is expected to have an update in May 2010.
Vitamin D is found in such foods as fatty fish (salmon, 794 IU per 3 oz serving), fortified milk (115-124 IU per cup) and cod liver oil (1,360 IU per tablespoon).