Vitamin D and Athletic Performance

A recently published study1 has demonstrated a correlation between vitamin D levels and performance. The subjects they used were sixty-seven professional male soccer players whom they measured for vitamin D level (25-OHD) correlations with performance during training season as well as the end of the off-season. What did they find? They found that vitamin D levels were lower during the testing pre-season vs. the testing post-season with performance between better pre-season vs. post-season. What does this suggest? It suggests the following two main points:

1) There’s possibly more demand for vitamin D during periods of intense training.
2) Vitamin D appears to have a direct impact on performance.

The demand for more vitamin D during periods of intense training could be a possible reason that levels were lower during the testing pre-season where training was more vigorous (and also performance was at a more positive level) whilst off-season levels of vitamin D increased but performance declined (another possible reason is that the athletes received more sun exposure as the post-season fell on peak summer season at the end of June and the beginning of July at a favourable latitude). It’s most likely however a combination of both more sun exposure as well as less stress stimulus.2 The take away here however is that vitamin D is an important micronutrient that has an impact on athletic performance.

You might be wondering, “If vitamin D levels were lower when performance was better, doesn’t that mean vitamin D negatively impacts performance?” If you had that thought cross your mind reading this post thus far, please allow me to point out the following:

  1. Vitamin D is essentially a hormone in the body and regulates a myriad of biological functions.
  2. There’s a lot of increased hormonal activity when one comes under increased physical stressors.
  3. The Waldron 2012 study suggests that a drop of vitamin D levels could possibly be due not to deficiency but due to increased systemic inflammatory response (inflammation being a major effect from exercise as it is this inflammation response which leads to muscle repair).

The role of vitamin D is actually a relatively new area of study and it’s becoming more and more frequent that we are seeing new data come out demonstrating the importance of having optimal vitamin D levels (25-OHD). It is also important to remember that the majority of people have below optimal vitamin D levels even when having frequent sun exposure. It’s also a micro-nutrient which isn’t found in abundance in food sources regardless of what your dietary preferences are (omnivore, carnivore, vegetarian, vegan, etc.).

With that, here are some tips on how you can make sure you have optimal vitamin D levels:

  1. Get bloodwork done for 25-OHD levels. <10 ng/ml is considered a severe vitamin D deficiency. <20 ng/ml is considered a vitamin D deficiency. <30 ng/ml is considered non-optimal. Thus what we would want to aim for is 36-48 ng/ml to be optimal.
  2. 1000 IU per day of vitamin D supplementation should get 50% of the population up to sufficient but below optimal vitamin D levels.
  3. 2000-5000 IU per day of vitamin D supplementation is usually the suggested rough estimates to hit optimal levels of vitamin D but this is contingent on where you are geographically located along with the time of year as well as how often you are exposed to peak UVB exposure.
  4. Being obese can factor into a vitamin D deficiency since vitamin D is fat soluable and whatever vitamin D your skin manages to produce may very likely get assimilated into your body fat before ever reaching circulation to do what it’s supposed to do. So obesity can in fact cause a vitamin D deficiency.
  5. When looking for vitamin D supplements, look for vitamin D-3 or cholecalciferol, as this is the active form of vitamin D which our bodies utilize.

As usual, Green Vibrance is an excellent product to consider as a source for D3 (1,000 IU per serving). It’s also a great foundational supplement to assist you on a healthier and better you.

About the Author: Steve L. is a consumer who uses Vibrant Health products. He is active in many online health-related forums.


  1. Koundourakis, Nikolaos E., et al. “Vitamin D and Exercise Performance in Professional Soccer Players.” PLOS ONE 9.7 (2014): e101659
  2. Waldron, Jenna Louise, et al. “Vitamin D: a negative acute phase reactant.” Journal of clinical pathology (2013): jclinpath-2012