Vitamin D: The ‘sunshine vitamin’ and muscle health
An afternoon lunch outside, a day at the beach, or simply getting some fresh air, you’ve likely heard someone say “I’m getting my vitamin D!” – or maybe you’ve said it?
Most people have heard our bodies can make vitamin D from the sun, but are we able to meet our daily needs from our afternoon sunbathing? Vitamin D is best known for helping build and maintain bone structure, and increases the absorption of calcium, which is the main mineral found in bones. Chronic low vitamin D intake leads to poor bone development in children and weak bones in adults. This can cause osteoporosis, or brittle bones, meaning you’re more likely to have a bone fracture or break.
Vitamin D also plays a role in immune function, protein synthesis and muscle function, inflammatory response, and regulation of skeletal muscle.
Based on the functions of vitamin D, what might the specific roles of the vitamin be for athletes and sport performance? While a lot of factors limit the amount of sun exposure that is turned into vitamin D, there is quite a bit of evidence that this sunshine vitamin can help support healthy athletes. More on that later.
There are several complicated steps involved with turning sun rays into vitamin D in the body. I’ll spare you the details. But let me present to you the realistic side of using the sun as a primary source of vitamin D. First and foremost, UV sun rays are quite damaging to our skin and increase the chance of skin cancer, so lathering up with sunscreen is a great defence against this damage. However, when we wear sunscreen, it blocks the UV rays from penetrating our skin, and UV rays are required for us to then make vitamin D in the body. But UV rays increase skin cancer risk, so sunscreen is more important than getting our dose of Vitamin D from the sun!
Further, other factors that reduce our ability to make vitamin D from the sun include the time of day, seasons (e.g summer vs. winter), cloud coverage, smog, and skin melanin (darker skin colors make less vitamin D). So athletes who train mostly indoors won’t get as much sun exposure as athletes training outdoors. A great comparison would be ice hockey players (indoor, winter sport) and track and field athletes (outdoor, spring sport). Ice hockey players will have significantly less sun exposure from indoor training or being covered in protective gear if playing outside. Whereas, track and field athletes will have higher sun exposure from training outdoors.
So, it looks like we need to turn to food for boosting vitamin D in athletes … although food sources might not be enough either. We will also discuss that later.