The Sun Shine Vitamin (Vitamin D) and Athletic Performance

You have likely heard that vitamin D plays a key role in bone health.  But did you know it is also essential to physical performance in relation to muscle strength, power, reaction time, balance, coordination, and endurance? It is well known that particular groups of the population are more likely to have low or insufficient blood levels of vitamin D, and some recent studies have shown low levels of vitamin D in athletes. Low levels of vitamin D can not only lead to increased risk for stress fractures but also respiratory infections and muscle injuries. The following explains the many roles vitamin D plays- make sure you get enough so you can keep performing.

Vitamin D plays significant roles in many functions in the body, including:

  • Bone Health: Vitamin D is needed for bone growth and maintenance. Low levels can enhance the rate of bone breakdown and increase the risk of bone injury such as stress fractures.
  • Muscle Health: Vitamin D helps to improve muscle protein synthesis, overall muscle strength and body stability/balance. Some studies show that vitamin D supplementation in athletes with insufficient levels can increase the size and amount of the fast twitch muscle fibres, which are important for short energy burst-type activities found in power and anaerobic sports.
  • Inflammation/Immunity: After intense periods of exercise, such as long-distance activities, there is a significant increase in inflammatory markers throughout the body, which can contribute to “overtraining” or “overreaching” syndrome. Studies show that enhancing vitamin D levels can reduce inflammation, therefore allow training to be resumed more quickly and with a less negative impact on overall performance. Maintaining sufficient vitamin D levels  may decrease the frequency of illness such as respiratory infections, gastrointestinal upset, and the common cold, which can all adversely affect athletic training and performance.  If you are not healthy enough to train, your performance can be negatively affected.

How much vitamin D is needed for benefits?

The current recommendation for vitamin D daily intake in adults 18-70 years old is 600 IU and should not exceed 4000 IU unless prescribed by an appropriate health care professional. This latter is the upper limit (UL) of vitamin D daily intake above which there is a risk of harm.  More is not better!

How can you increase your vitamin D?

Vitamin D is called the “sunshine” vitamin because our bodies can make vitamin D when our skin is exposed to a sufficient amount and strength of sunlight (specifically ultraviolet B rays). A number of factors hinder this process: training or competing in northern latitudes (especially during the winter months), practice indoors, consciously avoiding sun exposure (including using sunscreen and/or covering your skin when outdoors) or if you have a darker skin pigmentation.

Due to public health concerns about the increased risk of skin cancer associated with sun exposure, the DRIs for vitamin D assume individuals have minimal sun exposure and that all vitamin D must come from food, beverages or supplements.

Well recognized good food sources of vitamin D include fish (salmon, mackerel, sardines, and tuna), egg yolks and milk (including flavoured milks), and fortified soy beverages. Check the labels of other potentially fortified beverages such as orange juice.

Bottom-line: It is well known that particular groups of the population have insufficient or low levels of vitamin D, and there have been recent studies that have shown low levels of vitamin D in athletes. It’s important for all athletes to get enough vitamin D because it is essential for several body functions needed for peak physical performance.

Don’t forget – chocolate milk is a great source of vitamin D and is an easy and delicious way to help boost your D intake for the day! Bookmark to get updates, event details and all the latest news from the original recovery drink.


  1. Girgis et al, 2014. Effects of vitamin D in skeletal muscle: falls, strength, athletic performance and insulin sensitivity. Clinical Edocrinology 80:169-181.
  2. Von Hurst and Beck, 2014. Vitamin D and skeletal muscle function in athletes. Curr Opin Clin Nutr Metabolism Care . Epub Aug 16, 2014
  3. Close et al, 2013. The effect of vitamin D(3) supplementation on serum total 25[OH]D concentration and physical performance: a randomized dose-response study. Br J Sports Med 47:692-696.
  4. Angeline et al, 2013. The effects of vitamin D deficiency in athletes. Am J Sports Med 41:461-464.