If you’re feeling like Popeye before opening a can of spinach, you may want to get more sun exposure, as vitamin D deficiency can weaken muscles, one study warned. The so-called “sunshine vitamin”, which is also found in foods such as oily fish, egg yolks, cheese and mushrooms, has long been known to play a role in the strength of bones.
However, in experiments with rodents, Australian researchers found that not getting enough vitamin D reduced the function of the mitochondria that give energy to the muscles. This likely reduced muscle function, performance, and recovery.
Avoiding Vitamin D deficiency improves muscles
Additionally, the findings suggest that preventing vitamin D deficiencies in older adults may have the potential to help prevent age-related muscle degeneration.
Recent studies have suggested that around four out of ten people in European populations may be deficient in vitamin D. This has also been suggested to be linked to an increased risk of various conditions, including cancer, COVID-19, and diabetes. .
” Our results show that there is a clear link between vitamin D deficiency and oxidative capacity in skeletal muscle ,” said article author and metabolism expert Andrew Philp. ” They suggest that vitamin D deficiency decreases mitochondrial function, rather than reducing the number of mitochondria in skeletal muscle .”
“We are particularly interested in examining whether s this reduction in mitochondrial function may be a cause of loss associated with age in the mass and skeletal muscle function.”
In their study, Dr. Philp and colleagues explored the effect of diet-induced vitamin D deficiency on skeletal muscle mitochondrial function in young male mice. Over a three-month period, the team fed the mice a diet with normal amounts of vitamin D, leading to levels of 30 nanomoles per liter, or one without deficiency-inducing vitamin D, with levels of just 3 nanomoles. per liter.
In humans, the researchers explained, a healthy level of vitamin D is 40 to 50 nanomoles per liter, and acute deficiency is defined as anything less than 12 nanomoles per liter.
Not sunbathing affects 37% loss in muscle mass
Although the induced deficiency in the mice was more extreme, it remained within the clinically recognized range. Blood and tissue samples were taken from the mice monthly to determine vitamin D and calcium concentrations, as well as mitochondria number and levels of function.
After the three months had passed, the researchers found that the function of mitochondria in skeletal muscle was affected by up to 37 percent , and that this was due neither to a reduction in the number of mitochondria nor to a reduction of muscle mass.
The findings suggest that inadequate levels of vitamin D can lead to a reduction in the amount of energy that muscles can produce, which, in turn, can lead to poor muscle function.
Given this, the researchers said, preventing vitamin D deficiency in older people can help maintain muscle performance and reduce the risk of related diseases such as sarcopenia , the progressive loss of skeletal muscle mass and strength.
With their initial study complete, the researchers now seek to establish exactly how vitamin D deficiency served to influence mitochondrial control and function in skeletal muscle of mice.
More studies will also be needed to investigate the direct effect of this vitamin deficiency on muscle function and strength in humans.
