Not getting enough vitamin D may lead to problems with completing everyday tasks later on in life.
A new study in the Journal of Clinical Endocrinology & Metabolism revealed that older people with vitamin D deficiencies were more likely to have at least one functional problem, such as getting around the house independently, compared to people with healthy levels of the vitamin.
"Seniors who have low levels of vitamin D are more likely to have mobility limitations and to see their physical functioning decline over time," lead author Evelien Sohl, a researcher with VU University Medical Center in Amsterdam, the Netherlands, said in a press release. "Older individuals with these limitations are more likely to be admitted to nursing homes and face a higher risk of mortality."
The authors pointed out that as much a 90 percent of older individuals are vitamin D deficient. Vitamin D helps build bone and muscle, and can help prevent the effects of bone diseases like osteoporosis. The sun can help the body produce vitamin D, and it is found naturally in foods like fish-liver oils, fatty fishes, mushrooms, egg yolks, and liver. Vitamin D is often added to milk as well.
CBS medical correspondent Dr. Holly Phillips said that part of why doctors are noticing people are vitamin D deficient is because they're more aware of this health problem and are testing for it.
"One of the reasons we're so vitamin D deficient is we're avoiding the sun and wearing sun screen," Phillips added. "That's great for skin cancer prevention, not such good news for our vitamin D levels."
Researchers looked at an older group of 762 people between ages 65 to 88 and also recruited a younger group of 597 people between 55 to 65. The subjects were tracked for six years as part of the Longitudinal Aging Study Amsterdam. Participants were asked about their abilities to perform normal activities like sitting down, standing up from a chair or walking outside for five minutes without stopping. Blood tests revealed their vitamin D levels, and participants were divided into three groups in order of vitamin D levels.
For the older group, people who reported the lowest vitamin D levels were 1.7 times more likely to have limitations with one physical activity than those with the highest levels. When looking at the younger group, those with the least Vitamin D were two times more likely to have difficulty with at least one everyday task than those who were in the group with the highest levels.
Additional problems were more likely to develop after three years in the most vitamin deficient older group, and after six years in the most vitamin deficient younger group.
"The findings indicate low vitamin D levels in older individuals may contribute to the declining ability to perform daily activities and 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."
Dr. Michael Holick, a professor of medicine, physiology and biophysics at Boston University School of Medicine, said that this study showed there was a necessity to look further into whether taking supplements could help with vitamin D deficiencies. He was not involved in the study.
"It would be very nice to have a vitamin D intervention study so that you could actually demonstrate that those that were vitamin D deficient, if you made their blood level of 25-hydroxyvitamin D above 30 ng/mL, which is what is in fact recommended by the Endocrine Society practice guidelines, ... that you could improve neurocognitive function, as well as muscle function, and improve overall health and welfare of people as they're aging," he said to Medpage Today.
The National Institutes of Health's Office of Dietary Supplements recommends adults 51 to 70 years old get 600 IUs of vitamin D each day and those 70 and older get 800 IUs daily.
For reference, three ounces of cooked salmon contain about 450 IUs of vitamin D, milk contains between 115 and 124 IUs, and a bowl of fortified cereal contains about 40 IUs of vitamin D.