The ‘d’eeper problem behind age-related muscle weakness

Sarcopenia is the progressive loss of muscle mass, strength and functionality associated with aging. But have you heard of its close cousin, dynapenia?

Dynapenia is defined as a loss of muscle strength that’s not caused by neurological or muscular diseases. As with sarcopenia, it’s related to aging and is a major risk factor for physical incapacity later in life.

People with dynapenia are more likely to experience decline in quality of life, frailty and falls. All of these can lead to disability and even death among older adults.

That’s why we’re constantly reminded to use or lose it. But have you noticed the older you get, the weaker your muscles feel — no matter how hard you try?

That’s because it’s not just an age problem and exercise isn’t enough…

The “D” problem in dynapenia

To start, researchers in Brazil and the United Kingdom selected a sampling of data for a group of individuals ages 50 and over — without dynapenia — from the English Longitudinal Study of Ageing (ELSA).

And, because grip strength is considered a strong indicator of overall muscle strength, that data was gathered for each participant. Any readings that fell below 26 kg for men and 16 kg for women at the end of the 4-year follow-up were found to indicate dynapenia.

As to the cause?

Well, results showed that:

  • Participants with vitamin D deficiency had a 70 percent higher risk of developing dynapenia by the end of the 4-year study period than those with normal vitamin D levels.
  • On the flip side, vitamin D supplementation was shown to reduce the risk of dynapenia in older people by 78 percent.

“This is itself an important finding as it shows that vitamin D deficiency heightens the risk of muscle weakness by 70 percent,” says Maicon Luís Bicigo Delinocente, first author of the study. “However, because we knew there are many worldwide cases of people with osteoporosis who take vitamin supplements, we needed to try to measure the effectiveness of vitamin D supplementation.”

Peak D3

Gives You the Vitamin D3 You Can’t Get From Sunshine Alone!


To do that, the researchers conducted an analysis that excluded individuals with osteoporosis and those who were already supplementing with vitamin D. Here’s what they found:

  • The risk of developing muscle weakness by the end of the study was 78 percent higher for subjects with vitamin D deficiency.
  • A vitamin D insufficiency was just as problematic. The risk for muscle weakness was 77 percent higher for those with insufficient levels of the vitamin than those with normal levels.

Tiago da Silva Alexandre, an author of the article and a professor at Federal University of São Carlos (UFSCar) in Brazil, observes one of vitamin D’s many roles is to help repair muscles and release calcium for muscle contraction kinetics. It has also been shown that the activity of the vitamin D receptors on muscle decreases with aging.

He also noted that the study analyzed data for people living in the U.K., where there are many fewer days of sunlight than in Brazil. And yet, Brazil is known to have high rates of vitamin D deficiency and insufficiency. “Indeed, this is the case worldwide,” he says.

Determining your vitamin D levels

“It’s necessary to explain to people that they risk losing muscle strength if they don’t get enough vitamin D,” Alexandre says. He recommends getting safe sun exposure, eating foods rich in vitamin D or taking a vitamin D supplement.

How do you know if you’re vitamin D deficient? The best way is to have your doctor test your vitamin D levels via a blood draw. However, if you’re having trouble getting a doctor’s appointment and want to get quicker results, you can use a home test kit from a company like Everlywell or myLAB Box.

But remember, this research indicated that a deficiency should not be your only concern. An insufficiency was just as harmful to muscle health.

More doctors are coming around to prescribing high doses of vitamin D for deficiency. When I was diagnosed with deficiency my doctor did. But they may not be so quick to write a script if they consider your levels merely insufficient, though this study is not the first to indicate a correlation between insufficiency and health problems.

Vitamin D supplements are available in dosages ranging from 400 IU, 800 IU, 1000 IU, and upwards to 2000 IU, 5000 IU and 10,000 IU. When choosing a vitamin D supplement, make sure it’s vitamin D3, which is almost twice as effective as vitamin D2 at raising vitamin D levels. 

Editor’s note: Are you feeling unusually tired? You may think this is normal aging, but the problem could be your master hormone. When it’s not working, your risk of age-related diseases skyrockets. To reset what many call “the trigger for all disease” and live better, longer, click here to discover The Insulin Factor: How to Repair Your Body’s Master Controller and Conquer Chronic Disease!


Vitamin D deficiency increases risk of losing muscle strength by 78% — Agência FAPESP

Are Serum 25-Hydroxyvitamin D Deficiency and Insufficiency Risk Factors for the Incidence of Dynapenia? — Calcified Tissue International

Management of Dynapenia, Sarcopenia, and Frailty: The Role of Physical Exercise — Journal of Aging Research

What is dynapenia? — Nutrition

Carolyn Gretton

By Carolyn Gretton

Carolyn Gretton is a freelance writer based in New Haven, CT who specializes in all aspects of health and wellness and is passionate about discovering the latest health breakthroughs and sharing them with others. She has worked with a wide range of companies in the alternative health space and has written for online and print publications like Dow Jones Newswires and the Philadelphia Inquirer.