Muscle fatigue is a common sign of vitamin D deficiency, research finds.
Vitamin D is vital for enabling the muscles to work efficiently.
Low levels of this vitamin are linked to poor energy and tiredness.
Taking vitamin D supplements helped people in the study to feel much less tired.
Vitamin D is also found in oily fish, egg yolks, fortified cereals and some margarine spreads.
The study examined 12 people with a severe vitamin D deficiency, before and after treatment.
Participants’ muscles were scanned to check their response to exercise.
The results showed that those taking vitamin D supplements for 10-12 weeks felt much less tired.
Dr Akash Sinha, the study’s first author, explained the results:
“The scans provided a unique window into what is really going on in the muscle as it works.
Examining this small group of patients with vitamin D deficiency who experienced symptoms of muscle fatigue, we found that those with very low vitamin D levels improved their muscle efficiency significantly when their vitamin D levels were improved.”
The fatigue they were feeling is likely due to problems in the body’s mitochondria.
Mitochondria are the ‘power stations’ within each cell in our body.
Without vitamin D the mitochondria cannot work efficiently.
After supplementation, participants’ mitochondria recovered more quickly from exertion.
Dr Sinha said:
“We have proved for the first time a link between vitamin D and mitochondria function.
Of the patients I see, around 60% are vitamin D deficient and most people living north of Manchester will struggle to process enough vitamin D from sunlight alone, particularly during winter and spring.
So a simple vitamin D tablet could help boost your energy levels – from within the cells.”
The study was published in the Journal of Endocrinology (Sinha et al., 2013).