Lack of vitamin D can impair your muscle function because it causes muscle cells to produce less energy, according to a study that is published in Journal of Endocrinology. The scientists use their study to argue that one can improve muscle function and reduce age-related loss of muscle strength in seniors by making sure they get enough vitamin D. If your muscles feel weaker during the winter period, you may want to consider taking a supplement.
Around 40 percent of the European population is believed to lack vitamin D. This increases the risk of many diseases such as infections, diabetes, and even cancer. Numerous studies link low vitamin D to impaired muscle function, especially in old age, and that increases the risk of fragility and perhaps even disability. Our skeletal muscle is of vital importance to our ability to move about and carry out daily activities. The muscle cells convert calories from food into energy inside the tiny energy-producing “powerhouses” called mitochondria.
Earlier studies indicate that reduced muscle strength in vitamin D-deficient individuals is linked to impaired mitochondrial function. The problem with identifying vitamin D deficiency as the underlying cause of muscle weakness is that many older people already suffer from age-related los of muscle mass – also known as sarcopenia.
In the new study, Dr. Andrew Philip and his team of scientists from Garvan Institute of Medical Research in Australia used mouse models to determine whether lack of dietary vitamin D affected the muscle function in young male mice. The mice were either given a diet with sufficient amounts of vitamin D or a diet with no vitamin D at all. The scientists used blood samples and tissue samples to determine levels of vitamin D and calcium and to measure markers of mitochondrial function. After consuming a vitamin D-depleted diet for three months, the function of muscle mitochondria in the mice was reduced by 37 percent.
According to the scientists, their study shows a distinct relation between lack of vitamin D and impaired muscle function, which is why it would be relevant to prevent older people from becoming vitamin D-deficient so they can maintain healthy muscles.
The study is published in Journal of Endocrinology. Although it indicates that low vitamin D impairs mitochondrial function, Dr. Philip is unable to explain exactly why. This is something the team of researchers plans to investigate in future studies.
Vitamin D and its lifelong role in muscle health
More and more evidence suggests that vitamin D plays a vital role in muscle health and muscle strength. This is crucial knowledge because so many individuals, older people in particular, suffer from different types of muscle disorders. According to a study from Trinity College Dublin that is published in Clinical Intervention in Aging, there is increasing evidence to show that having adequate levels of vitamin D in the blood can protect against loss of muscle mass and diseases that follow in the wake of this. The scientists behind this study observed that:
- Lack of vitamin D is common among older people
- Vitamin D-deficient seniors had twice the rate of muscle weakness compared with seniors who had sufficient levels of the nutrient
- Impaired muscle function was three times higher in older people with vitamin D deficiency compared with those who had enough vitamin D
- The study confirmed the benefits of being physically active
- It is commonly known that lack of vitamin D leads to bone diseases that are important to prevent
- According to the scientists, this strategy should be included in the prevention of muscle disorders
Vitamin D sources and requirements
Sun exposure is our main source of vitamin D, which our skin synthesizes in response to UVB rays. At our latitudes, however, this biological process is only possible during the summer period. There is generally very little vitamin D in the diet. Therefore, the Danish Veterinary and Food Administration has issued new guidelines for vitamin D supplementation, but many people are not aware of this.
Our actual need for vitamin D hinges on different factors such as sun exposure, age, skin type, BMI, and the presence of chronic diseases. High-dosed (20-100 micrograms) vitamin D supplements are available on the market.
EU’s Scientific Committee on Food has established a safe upper intake level for daily vitamin D intake at 100 micrograms for adults, including pregnant and breastfeeding women. Vitamin D is lipid-soluble. Therefore, the best way to absorb and utilize the nutrient from supplements is if it is bound to oil in soft gelatin capsules.
Stephen P Ashcroft et al. Diet-induces vitamin D deficiency reduces skeletal muscle mitochondrial respiration. Journal of Endocrinology. 2021
Society for endocrinology. Vitamin D Deficiency Can Impair Muscle Function. www.scitechdaily.com 2021
Niamh Aspell et al. Vitamin D Deficiency is Associated With Impaired Muscle Strength And Physical Performance in Community-Dwelling Older Adults: Findings From The English Longitudinal Study Of Ageing. Clinical Interventions in Aging. 2019
Trinity College Dublin. Vitamin D deficiency is associated with poor muscle function in adults aged 60+. ScienceDaily. 2019
Christian M. Girgis et al. Mice with myocyte deletion of vitamin D receptor have sarcopenia and impaired muscle function. Journal of Cachexia, Sarcopenia and Muscle, 2019
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