Could a deficiency in vitamin D be undermining your athletic performance, affecting both muscle function and levels of fitness? Vitamin D insufficiency is on the rise and, in the USA, up to 80% of the adult population have suboptimal levels. Athletes that have a very low body fat or mainly train indoors are at risk also of developing a deficiency in this invaluable vitamin. Although they are not at greater risk than the general population, athletes may be more sensitive due to the nature of intense training.
One study into vitamin D and athletic performance looked at Caucasian football players, testing them at the commencement of the study and another at the end of their ‘off season’ period. At the start of the study, which commenced just after their intensive training and playing season their vitamin D levels were lower than the second test, indicating that physical exertion depleted their levels of vitamin D.
Vitamin D and our health and athletic performance
Vitamin D is a fat soluble vitamin that exists in two main forms; vitamin D2 and vitamin D2. We gain vitamin D3 through synthesising ultraviolet rays in our skin when it is exposed to the sun. We also obtain small amounts from a number of animal sources, particularly oily fish, liver and egg yolks. Vitamin D2 is obtained from plant sources such as mushrooms, but we also typically find both types of vitamin D in fortified foods.
Our general health is reliant on having optimal levels of this vitamin; its ability to promote healthy bones through the absorption of calcium is well known, but there is also mounting evidence that deficiencies in vitamin D can lead to an increased risk of diabetes, muscle and bone pain and various cancers.
In terms of athletic performance, its benefits can be evaluated in the following ways:
- Impact on musculoskeletal structures; its benefits for bone strength is the biggest argument for vitamin D supplementation, as a deficiency can lead to stress fractures. There is less clear evidence for how it assists muscle recovery.
- Vitamin D is proven to have a powerful impact on immunity and allergies and athletes that have higher vitamin D levels have fewer upper respiratory tract infections.
- Other benefits; vitamin D deficiency has been linked to depression and cognitive impairments, but the benefits for promoting a positive mental attitude in the athlete has not been investigated.
The top-flight athlete and vitamin D supplementation
The stress of intensive training, the need to ‘bounce back’ quickly and the importance that even the smallest improvement can bring to performance indicates that vitamin D levels should be evaluated. Professor Cathy Speed is a Sport & Exercise Medicine Specialist who provides a holistic approach to health and fitness; her advice is to screen for vitamin D deficiency at a pre-season screening and also be aware that some athletes are particularly at risk, including those with limited sun exposure, female and/or older athletes and those that are seeing a poor recovery from training or recurrent injury.
For more information on Cathy’s Cambridge Sport & Exercise Medicine Clinic call 01223 200 595 to make a consultation.