Vitamin D Makes You Better

We’ve known for a while that athletes tend to perform better in the summer months than they do during the winter. Some people have hypothesised that one of the reasons for this is that the higher levels of UV light in the summer increase the body’s production of vitamin D. A 2013 study found that while further research is needed before we can definitively say that vitamin D suplemments directly improve performance, maintaining optimum vitamin D levels should be an important goal for athletes due to its many health benefits.

Sources of vitamin D

One of our main sources of vitamin D is our skin’s reaction to sunlight, and in the UK from early April until the end of September it’s possible to get all the vitamin D we need from being out in the sun. If you spend most of your day indoors or wear clothes that cover up most of your skin though you won’t be getting as much as you need. During the winter months we don’t get any vitamin D from sunlight.

Vitamin D isn’t really abundant in foods but there are some good dietary sources of it such as oily fish, liver, and fortified foods such as fat spreads and breakfast cereals.

Potential effects of vitamin D deficiency

Vitamin D plays a crucial role in many vital physiological functions and sub-optimal levels can cause a variety of problems that can hurt your ability to train and perform at the level you want to. As well as being a key reason for the loss of muscle mass and strength as we age, low levels of vitamin D can also leave you with poor bone density, a weaker immune system, and chronic feelings of tiredness and weakness. In a more general sense, vitamin D deficiency also increases the risk of certain cancers and cardiovascular diseases and can be a cause of high blood pressure.

How vitamin D benefits athletes

If you’re not getting enough in your day to day life, taking vitamin D supplements can indirectly improve athletic performance by lowering the risk of injury, decreasing chronic exercise related pain, and improving general muscle performance.

The discovery of vitamin D receptors within muscle also suggests a significant role for vitamin D in muscle tissue function, particularly in cellular growth and inflammatory response. A common symptom of vitamin D deficiency is muscle weakness, so supplementation can also help keep them functioning properly and keep you strong.


Our bodies rely on replenishing stores of vitamin D daily to meet its requirements as we often don’t get enough in our diet generally, let alone enough for there to be any significant stores of it in the body. By making sure you’re getting a healthy amount by taking vitamin D supplements, particularly during the winter months, you can reduce your risk of injury and improve your general health. Athletes often find that they’re at peak physical fitness during the time of the year UVB levels and natural vitamin D production are at their highest, so vitamin D supplementation can be a great way of making sure you’re performing at your peak at all times.