Researchers at the University of Birmingham have shown that increasing the levels of someone’s active vitamin D can help to optimize their muscle and bone strength. Vitamin D is known to have many benefits, including increasing skin health and mental health, on top of muscle and bone health. The key component in the conducted study is active vs. inactive vitamin D.
Vitamin D Could Increase Muscle Health
The study builds on previous knowledge that shows levels of inactive vitamin D to be associated with a lack of muscle mass. The research is the result of a cutting-edge technique that allowed researchers to monitor both active and inactive forms of vitamin D alongside their impact on various muscle functions.
Dr. Zaki Hassan-Smith, from the University of Birmingham, explains, “We have a good understanding of how vitamin D helps bone strength, but we still need to learn more about how it works for muscles. When you look at significant challenges facing healthcare providers across the world, such as obesity and an aging population, you can see how optimizing muscle function is of great interest.”
“Previous studies have tested for the inactive forms of vitamin D in the bloodstream to measure vitamin D deficiency. Here, we were able to develop a new method of assessing multiple forms of vitamin D, alongside extensive testing of body composition, muscle function and muscle gene expression.”
Active vs. Inactive Vitamin D
Inactive vitamin D is the body’s stored form of vitamin D and cannot be fully utilized until it has been activated. The essential activation agent is magnesium. If you don’t have enough magnesium in your body, your stored vitamin D doesn’t activate, and you can become vitamin D deficient.
More Lean Mass Can Equal More Vitamin D
The study was comprised of 116 healthy participants who had both active and inactive levels of vitamin D measured alongside physical characteristics, including body fat and ‘lean mass,’ a measure of muscle bulk.
The study concluded that women with a healthy body composition and lower body fat were less likely to have high levels of inactive vitamin D, a marker of vitamin D deficiency. This result was echoed by the evidence stating levels of inactive vitamin D were lower in women with increased body fat. This would suggest there is a relationship between vitamin D and body composition.
However, the active form of vitamin D was not associated with body fat but was instead associated with lean mass. Individuals with an increased lean mass and muscle bulk had a higher level of active vitamin D in the bloodstream.
Dr. Hassan Smith added, “By looking at multiple forms in the same study, we can say that it is a more complex relationship than previously thought. It may be that body fat is linked to increased levels of inactive vitamin D, but lean mass is the key for elevated levels of active vitamin D. It is vital to understand the complete picture and the causal mechanisms at work so we can learn how to supplement vitamin D intake to enhance muscle strength.”
Vitamin D for Women
In this study some of the positive associations between active vitamin D and muscle bulk were not seen in men and only in women. Future studies with larger cohorts will help to identify if this is due to biological differences. The research team at the University of Birmingham are now working alongside international collaborators to further investigate the mechanisms at work through lab-based studies and clinical trials. They hope that the findings will inform and shape the design of future supplementation studies and begin to answer questions about the optimal levels of vitamin D required for healthy muscles and brain health.
References:
Materials provided by University of Birmingham.
Vitamin D Activation – a little known fact – Magnesium and Health
