Garth Fox - Scientific Performance Coaching
Scientific Performance Coaching

"The world belongs to the energetic." - Ralph Waldo Emerson
Twitter   LinkedIn   LinkedIn

< Back to articles

Article - 25 May 2011

Vitamin D deficiency. Does D stand for 'die early'?

Vitamin D is good for strong bones and teeth, right? And anyway you get it from the sun so what is there to think about? Well what if I said that not only does new evidence suggest that low vitamin D status is linked to a whole raft of very serious health issues such as increased rates of multiple sclerosis, cancer, heart disease, immune system disfunction, rheumatoid arthritis and bowel disease to name but a few, but it is also quite likely that you are not getting enough.

"Vitamin D deficiency is endemic in the general population. This can now be linked to cardiovascular disease, diabetes, depression, multiple sclerosis, rheumatoid artritis and certain types of cancer". (Med Sci Sports Exerc 2011)

First of all, what is vitamin D? For one, it is more like a hormone  than a vitamin in that it acts as a chemical messenger and exerts a powerful effect on cells. There are two types - D2 and D3. D3 is the most active  and is also the one that is produced in our bodies through exposure to sunlight, or more precisely to UVB rays. We are also able to get it from certain foods such as oily fish, liver, eggs,  milk - the usual suspects. So far, so boring I hear you say. Well listen up, this is the problem:

Even if you live in the South of France, are partial to the sunbed and love your sardines, it is likely, certainly during the winter months, that you are still not getting the amount of vitamin D that you actually need to help fend off the myriad of health issues previously mentioned.  For athletes this deficiency has also been shown to directly influence the frequency of common colds and flu - not great when trying to progressively build fitness.  I am not usually one for scaremongery, but be afraid. This is serious. Government guidelines must be on top of this though, right? Wrong. Follow those - stay out of the sun between 11am-3pm and get 200IU of vitamin D daily -  and, according to the latest evidence you will certainly, no doubt about it, be deficient. The reason being is that the best way to get what you need  is from the sun but to do that you need to live somewhere where the winter latitude is less than 37 degrees north or south. To give you an idea, Rome is on a latitude of 42 degrees and London 52 degrees. Anyone want to move to Hawaii with me? (21degrees).  Ok fine, but what about the risk of skin cancer you say? As with anything, moderation should prevail. Do not get burnt but regular sun exposure is certainly going to be beneficial and this is a sentiment backed up by US researchers who argue that the improved vitamin D status that would accompany increased sun exposure would decrease overall mortality rates and eclipse those from skin cancer by a factor of 12.
"Athletes living at distances away from the equator need supplemental vitamin D during the winter. Maintaining sufficient vitamin D status may reduce the risk of common infectious illness which can negatively impact athletic training and performance".(Med Sci Sports Exerc 2011)

So how much do we need? UK goverment guidelines suggest 200IU/day. US guidelines have just been moved to 600 IU/day. Recent research suggests a figure of 1500 IU/day might be more realistic! As athletes this becomes even more important because of the link to overuse injuries and stress fractures.

The conclusion to be drawn from all this is that vitamin D is much more important than we ever knew.  So just make sure you are getting enough. Get out in the sun, eat the right food and live somewhere hot and sunny. Failing that get down the shops and buy some pills. If you don't it might just killl you.

Read the previous article: New to Open Water Swimming? Relax, but know this..

Read more articles >

Contact Garth for a chat about your requirements >

Read our frequently asked questions >

Try our Bespoke Training Camps, High Performance Coaching, or Sports Science services >

  • When I met Garth in 2013, in my late 40s, I was already in reasonable shape. Or so I thought! The programmes Garth has set for me have coaxed me along to a much higher fitness level.

    Brian Shea, Investment Banker, Surrey

    Read the full testimonial >

  • Hi Garth
    Many thanks for a truly memorable weekend. The training, teaching and experience was fantastic: I was still reliving some of those climbs on the plane home! It was also great to meet your lovely family.
    Thank you again and I can’t wait to get back down for another weekend of precision training.

    David Persaud, London May 2015

    Read the full testimonial >

  • I was fairly new to cycling. I loved it, but felt like I had reached a plateau - I was suffering from frequent illness and injury, I didn't see much reward out for the extra effort in, and consequently my motivation was starting to falter. By good fortune, the gurus at Cyclefit recommended Garth Fox - and I haven't looked back since.

    Max Kirby

    Read the full testimonial >

  • {Garth is} a man of integrity, who seems to be driven by nothing more than a desire to help others to achieve their dreams - be these to finish a sprint triathlon, or to qualify for Kona - Garth will be at your side (sometimes literally!) every step of your journey. You're in safe hands.

    Professor Alison McConnell, BSc, MSc, PhD, FBASES, FACSM.
    Professor of Applied Physiology, Brunel University, UK. Author of "Breathe Strong, Perform Better"

    Read the full testimonial >

  • My goal after having two children was to get back to at least the level of 10k running performance I was at before having children, which was 50 mins. Under Garth's highly professional guidance I recently managed a time of 45 mins and came 6th in my age group! I am ecstatic and have already set my sights on a triathlon next year. As Garth always tells me, the limits are only where you set them. Thankyou!

    Karine Seguin - Head of European Business Development – Financial services sector, London

  • Garth's success in the field of sports physiology begins with his passion and respect for endurance events and the human body. He has a deep understanding of the connection between training, racing, recovery, and nutrition and how proper balance in life can optimize one's performance.

    Michi Weiss - Pro Ironman Triathlete.
    2011 Xterra World Champion, Olympian and 4X Ironman Champion.

    Read the full testimonial >

  • Garth's enthusiasm for endurance sports physiology seemingly knows no bounds. He has a great understanding of the human body and how it responds to rest and training. He's also one of those rare people who have both communication and analytical skills, when most people only have one or the other.

    Phil Mosley - Elite Triathlete & Coaching Editor of Triathlon Plus magazine

    Read the full testimonial >

  • Garth really knows how to connect the dots between training and performance. His enormous expertise in physiology and sports science makes his training interventions very perceptive and his ability to tease out the precise adaptations required for the desired improvement in performance with different training stimuli is uncanny.

    Peter Leo - U23 Triathlete - Student of Sports Science

    Read the full testimonial >

Latest Article:
Run Your Best Marathon..


Bespoke Training Camps
High Performance Coaching
Sports Science Services
About Garth
About Peter Leo
About Health & Fitness
In the media
Frequently Asked Questions

Share with your friends:

© 2020 Garth Fox. Website design by Ambrose Fox - Tailored Web Solutions.

Associations & Memberships:


Click here to log into Training Peaks >