Low vitamin D levels impair stamina and performance over time

June 25, 2018 by Ellen Goldbaum, University at Buffalo
To better understand how low levels of vitamin D affect physical performance, Bruce Troen, left, and Kenneth Seldeen studied mice with insufficient vitamin  D levels over the long term. Credit: University at Buffalo

It's generally accepted that most adults in the U.S. don't get enough Vitamin D, but how that impacts their muscle mass and function over the long term is not well understood.

Researchers in the field have been split over vitamin D's importance in physical and cognitive function throughout the aging process. Part of the challenge has to do with the fact that studying humans for several decades is difficult.

Earlier this month, researchers at the University at Buffalo who also are affiliated with the U.S. Department of Veterans Affairs published in the journal Aging results of an animal study that may be one of the first to examine how low levels of vitamin D affect over the long term. While the study involved mice, not humans, the researchers say it eliminated some of the confounders possible in human studies, such as genetic or lifestyle factors, like diet and exercise, that can complicate the results.

"The findings of our study suggest that the relatively short-term, one-to-two-year studies that have failed to find differences in outcomes with vitamin D supplementation may not be adequate to comprehensively assess whether or not vitamin D plays an important role in physical performance as we age," said Bruce R. Troen, MD, senior author, professor and chief of the Division of Geriatrics and Palliative Medicine, Department of Medicine in the Jacobs School of Medicine and Biomedical Sciences, and director of the UB Center for Successful Aging. Troen is a physician with UBMD Internal Medicine.

"The take-home message of this study is that while having low serum vitamin D for a month or even a year or two may not matter for a person, yet over several decades it may have clinical ramifications," explained lead author Kenneth L. Seldeen, Ph.D., research assistant professor of medicine in the Jacobs School.

Both Troen and Seldeen and some of their co-authors are also with the Veterans Affairs Western New York Healthcare System.

"This is particularly concerning since an estimated 50-70 percent of the national population is either vitamin D deficient or insufficient," he said.

While most animal studies involve complete dietary elimination of the vitamin or knockout animals, who lack receptors for the vitamin, the UB study examined vitamin D insufficiency, which more accurately reflects the level of serum vitamin D in the general population.

"Vitamin D deficiency, defined as 12 nanograms per milliliter or less is relatively infrequent nowadays, whereas vitamin D insufficiency, less than 30 ng/ml, is widely prevalent and likely lasts for decades," said Troen.

Vitamin D insufficiency was induced in mice aged six months—the equivalent of a 20–25-year-old human for one full year—which is the equivalent of an additional 25-30 human years. A control group received vitamin D at normal levels.

After two weeks, the mice with low vitamin D exhibited a rapid decline in their serum vitamin D levels down to 11-15 ng/ml, where they remained for the duration of the study.

These mice performed worse than controls on several measures; they include grip endurance, which is the ability to maintain strength in a grip, sprint speed and stride length, meaning the mice took shorter steps, which may indicate slow gait speed, an important clinical parameter in geriatric medicine.

Troen noted that interestingly, there was no difference in grip strength between the two groups, but that the difference noted in grip endurance may be significant.

"The decline in grip endurance likely represents a decline in anaerobic capacity, the ability to maintain peak performance," said Troen. "That was reinforced by the corresponding decline we observed in uphill sprint capacity. Together, these tests implicate that vitamin D status is an important factor for maintaining this critical aspect of physical performance."

The researchers were intrigued by the finding that after eight months the low vitamin D mice were found to have less lean body mass than the controls, but that difference went away after 12 months.

"The loss of lean body mass with aging is extremely important and inexorable," said Troen. "Our data suggest that D status plays a role in lean body mass, but more studies—both on geriatric mice and older humans—are needed."

The research was funded by the Veterans Affairs Rehabilitation Research and Development Grant and the Indian Trail Foundation.

Explore further: Vitamin D supplementation doesn't change lean mass, BMD

Related Stories

Vitamin D supplementation doesn't change lean mass, BMD

April 11, 2016
(HealthDay)—For postmenopausal women with vitamin D insufficiency completing a structured weight-loss program, vitamin D3 supplementation is not associated with changes in lean mass or bone mineral density (BMD), according ...

High intensity interval training can reverse frailty at advanced age, preclinical study finds

August 4, 2017
Growing older may not have to mean growing frail. A preclinical study has revealed that brief periods of intense physical activity can be safely administered at advanced age, and that this kind of activity has the potential ...

Vitamin D doesn't impact insulin sensitivity, secretion in T2DM

May 10, 2017
(HealthDay)—For patients with type 2 diabetes (T2D) and vitamin D deficiency, vitamin D supplementation has no impact on insulin sensitivity or secretion, according to a study published online May 3 in Diabetes Care.

Low vitamin D levels if you're lactose intolerant

May 23, 2017
Those with a genetic intolerance to lactose may suffer from a vitamin D deficiency. That's according to a recent study conducted at the University of Toronto and published in the Journal of Nutrition.

Vitamin D deficiency increases risk of chronic headache

January 4, 2017
Vitamin D deficiency may increase the risk of chronic headache, according to a new study from the University of Eastern Finland. The findings were published in Scientific Reports.

Increased levels of active vitamin D can help to optimize muscle strength

February 15, 2017
Researchers at the University of Birmingham have shown that increasing the levels of active vitamin D can help to optimise muscle strength in humans.

Recommended for you

India launches 'Modicare', world's biggest health scheme

September 23, 2018
India on Sunday launched the world's biggest health insurance scheme which Prime Minister Narendra Modi said would cover some 500 million poor people.

Patient-centered visual aid helps physicians discuss risks, treatments with parents

September 21, 2018
A series of illustrations and charts designed as decision aids for parents of children with minor head injuries helped them communicate with emergency medicine physicians and make informed decisions about their child's care, ...

Alcohol responsible for one in 20 deaths worldwide: WHO

September 21, 2018
Alcohol kills three million people worldwide each year—more than AIDS, violence and road accidents combined, the World Health Organization said Friday, adding that men are particularly at risk.

Smart pills dumb down medical care, experts warn

September 21, 2018
Enthusiasm for an emerging digital health tool, the smart pill, is on the rise but researchers at the University of Illinois at Chicago have published a paper in the American Journal of Bioethics that cautions health care ...

Crunched for time? High-intensity exercise = same cell benefits in fewer minutes

September 20, 2018
A few minutes of high-intensity interval or sprinting exercise may be as effective as much longer exercise sessions in spurring beneficial improvements in mitochondrial function, according to new research. The small study ...

China's doctor shortage prompts rush for AI health care

September 20, 2018
Qu Jianguo, 64, had a futuristic medical visit in Shanghai as he put his wrist through an automated pulse-taking machine and received the result within two minutes on a mobile phone—without a doctor present.

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.