OK, so I have covered the importance of adequate quality sleep and joint impact on your progression and health as an athlete. Now, as the nights draw in on those of us in the northern hemisphere I want to look at Vitamin D: AKA the "sunshine vitamin", AKA the most likely vitamin you, as an athlete, will be deficient in.
What is Vitamin D and why is it important to athletes?
Vitamin D can be obtained in the diet, made in the body or generated by sunlight hitting our skin. It is vital to a large number of body functions important to us athletes including:
1. Calcium use for building and repairing bone (strong bones to hang strong muscles off)
2. Nerve to muscle signalling (from hand-eye co-ordination to muscle activation in heavy lifts)
3. Inflammation (read: Injury recovery)
4. Cell growth and repair (read: general recovery)
People will also tell you that Vitamin D deficiency also contributes to Seasonal affective disorder (SAD). This "winter blues" phenomenon could potentially kill off your self confidence and athletic drive. This in itself may influence training and performance.
Athletes are likely to be vitamin D deficient as they tend to use up more vitamin D than normal. Where I haven't looked into this in detail, I am guessing that higher metabolic demands from working muscles as well as more bone and muscle tissue adaptation and repair requirements simply mean athletes are likely to use more for metabolic processes.
Vitamin D studies and the athlete
Early studies on Vitamin D in the althete found that taking more could enhanced performance. Nowadays this isn't thought to be the case specifically. Instead, it is thought that getting adequate vitamin D simply prevents the potential loss in performance from being deficient.
Furthermore, research shows that if you don't get enough and you could be more prone to injury:
http://bit.ly/te9UkU (NFL football player study)
...suffer from more winter-associated illnesses like colds and flu:
...and even begin to slow on reaction time:
How to prevent Vitamin D deficiency?
So how should you, as an athlete, ensure you get enough vitamin D? Where dietary supplements are an option, there are good, healthy alternatives like spending more time outside or eating vitamin D rich food such as oily fish. The following infographic is awesome and will give you an overview of the issue and how to tackle it.
A word of caution from a vitamin D expert:
“Studies suggest that taking too much vitamin D (more than 5,000 IU/day) may actually worsen athletic performance. Take enough to keep your 25‑HD levels around 50 ng/mL, year‑round.”
Personally I recommend increasing Vitamin D in the body all year round by getting regular sun exposure in the summer, and using supplementation or altering your diet in the winter or when you think you aren't getting enough sunlight. We are currently working on an HMB and Vitamin D supplement for athletes in the winter. Watch this space.