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Vitamin D for athletes

Sports Nutritionist Renee McGregor explains why athletes may be vitamin D-deficient, why this could be a problem for performance, and what can be done about it.

Vitamin D is made in our bodies from sunlight. However, those who live in countries where sunlight might be limited, those who spend little time outdoors; including athletes that do a high volume of their training indoors, those who cover up with high-factor sunscreen and those who are darker-skinned, may actually be at risk of a vitamin D deficiency. A vitamin D deficiency can lead to several health issues such as:

  1. Chronic fatigue
  2. Depression
  3. Increased risk of bone injury
  4. Chronic musculoskeletal pain
  5. Viral respiratory tract infections

There also seems to be strong emerging evidence that supplementing an athlete who has sub-optimal levels of vitamin D with up to 4,000 IU vitamin D3 (the form of vitamin D that is made naturally in the body) has real benefits to performance, particularly in strength, power, reaction time and balance.

Presently there is no universally accepted definition for vitamin D but the following classifications from blood test levels are often cited:

  1. When blood levels are below 50nmol/L - deficiency
  2. When blood levels are below 75nmol/L - insufficient levels
  3. Levels between 75-120nmol/L - ideal range

It is not possible to meet your Vitamin D requirements through food alone but small amounts of vitamin D can be found in the following foods:

  1. Oily fish
  2. Egg yolks
  3. Fortified foods such as milk, margarine, cereals

Vitamin D supplements are readily available but if you are an athlete, always make sure that you buy from a reputable source. The most recent guidelines (Jan 2015) produced by UKAD, the UK anti-doping agency, have introduced higher sanctions for those that fail a drugs test. It is important to note that these new sanctions can be applicable to both athletes and in some cases practitioners or support staff as well.

It is essential that any supplement, including vitamins and minerals should be batch tested and preferably independently accredited under the Informed-Sport program. Although this does not guarantee that a product is safe completely it does provide athletes with highest level of assurance available. If an athlete can show proof that have only taken products accredited by Informed-Sport, it demonstrates that they have not purposefully gone looking for performance enhancing aids.

Renee McGregor RNutr is a registered sports nutritionist working with a variety of athletes including elite GB/Commonwealth marathon runners, England Netball pathway athletes and junior tennis academy players. She also contributes to a number of sports publications including The Telegraph, The Guardian, Outdoor Fitness and Run Ultra.

Find out more about Renee McGregor.

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Nothing beats a healthy, balanced diet to provide all the nutrients we need. But when this isn’t possible supplements can help. This article isn’t intended to replace
medical advice. Please consult your healthcare professional before trying supplements or herbal medicines.