Vitamin D Is an Essential Energy Nutrient

An underlying cause of fatigue can be suboptimal mitochondrial function, and Vitamin D deficiency is a well-recognized cause of fatigue and myopathy.    Akash Sinha, from Newcastle University (United Kingdom), and colleagues used non-invasive magnetic resonance scans to measure the response to exercise in 12 patients with severe deficiency before and after treatment with vitamin D.  The team found that exercise recovery rates significantly improved after the patients took a fixed dose of oral vitamin D for 10-12 weeks, with the average phosphocreatine recovery half time decreasing from 34.4 sec to 27.8 sec. All patients reported an improvement in symptoms of fatigue after having taken the supplements. In a parallel study, the group demonstrated that low Vitamin D levels were associated with reduced mitochondrial function.  Explaining that: “[Vitamin D] therapy augments muscle mitochondrial maximal oxidative phosphorylation following exercise in symptomatic, vitamin D deficient individuals,” the study authors submit that: “This finding suggests that changes in mitochondrial oxidative phosphorylation in skeletal muscle could at least be partly responsible for the fatigue experienced by these patients. For the first time, we demonstrate a link between vitamin D and the mitochondria in human skeletal muscle.”