‘Solar power’ for human beings

A very good friend of mine’s daughter is planning to write a dissertation for a school project. She previously had a stress fracture and then turned out to have very low levels of vitamin D. When I offered advice regarding testing and taking of vitamin D, I mentioned that the vitamin D might have some side-benefits for her. She is a keen and talented athlete. As I mentioned to her father, there’s quite a lot of evidence linking vitamin D with enhanced fitness and sporting performance. Her father suggested that a good subject for his daughter’s dissertation might be vitamin D in athletes, and I am very inclined to agree.

This reminder of the role of vitamin D physical function caused me to search for a relevant review study I had lurking on my hard drive [1]. Sporting and physical performance has some seasonal variation: peaking in late summer before dropping off again in the autumn (fall) and winter. The idea here is the higher levels of vitamin D from sunlight exposure improves athletic performance. Some direct evidence comes for this idea in the form of evidence finding that vitamin D can enhance muscle synthesis and strength, as well as balance and reaction time.

The main point of this post, is to briefly summarise the evidence the review presents in terms of the impact of light on fitness and physical performance. Here’s a summary of the findings of the main studies highlighted by the review and their dates:

1938 – ultraviolet irradiation found to improve speed in the 100-metre sprint in four students compared with matched controls. Average times improved 1.7% in the non-irradiated controls undergoing training compared to 7.4% in irradiated students undergoing identical training.

1944 – 32 medical students were exposed to UV light, twice a week for 6 weeks. This led to a 13 per cent improved performance on a stationary bike compared to no improvement in controls.

1945 – irradiation over a 10-week period in individuals undergoing training saw a 19 per cent increase in fitness, compared to a 1.5 per cent improvement in controls.

1952 – German schoolchildren were exposed to UV lights at school for 9 months of the year. Compared to non-exposed children, light-exposed children were 56 per cent fitter in the early spring. This study also found that supplementing children with vitamin D replicated the effects of light exposure in terms of fitness enhancement.

1954 – UV light in the vitamin D-producing range was found to be most effective for increasing performance on a stationary bike.

1956 – UV light found to improve muscle strength and cycling performance in 6 out of 7 subjects.

1967-69 – Three studies that found a single dose of UV light found to improve strength, speed and endurance in women.

This research, spanning several decades, presents a quite powerful argument for optimisation of vitamin D levels in athletes and other looking to get the best from their bodies, I think. It seems odd that one little vitamin might have the power to enhance physical functioning in this way. Except that vitamin D is not a vitamin, it’s a hormone – and one that is being recognised as having wide-ranging benefits for the body.

The review that forms the basis for this post also quotes evidence finding that in populations, physical functioning is best at a vitamin D level of about 50 ng/ml (125 nmol/l). Such levels are also linked with protection from a wide variety of ills including heart disease and several forms of cancer.


1. Cannell JJ, et al. Athletic Performance and Vitamin D. Med Sci Sports Exerc 2009;41(5):1102-10

11 Responses to ‘Solar power’ for human beings

  1. Ted 4 May 2011 at 7:15 pm #

    Dr. Cannell has an excellent website on Vitamin D – http://www.vitamindcouncil.org

  2. Roy 6 May 2011 at 5:38 pm #

    For info in how D level correlates with cancer prevention see the Univ of California site

  3. climberK 6 May 2011 at 5:52 pm #

    I asked my GP today whether I could have a vit D test for my 3 year old, who’s been having more than his fair share of infections this last winter and seeing that vit D deficiency is widespread.

    My GP readily agreed that about 70% of the UK population are vit D deficient but said that testing is not usually done unless there are symptoms such as fractures or deformed bones!!!

    So must for preventative medicine on the NHS…

  4. Radiant Lux 6 May 2011 at 7:02 pm #

    I’m curious about the UV light. I went to a health conference in 2006 and it was recommended to switch my lightbulbs with full spectrum compact fluourescent bulbs for health and energy conservation measures. Would that be enough UV light? I am also giving them cod liver oil, probiotics and occasional vitamin D supplements.

  5. Ann-Marie 14 May 2011 at 1:12 pm #

    1. What advice can you provide for amounts of D3 to supplement after 3 surgical procedures for basal and malanomas in the the past three months on scalp…had to have skin grafts to cover (man is 58 yrs.)
    2. Need advice for the best type of head cover to prevent more skin damage as I think you have more available products in the UK. We live in FL, USA.
    Please advise…thanks so much

  6. Nathan 14 May 2011 at 6:10 pm #

    Interesting article. The biggest change I noticed with Vitamin D supplementation is that my mood improved through the long winter months.

  7. Kevin Greer 17 May 2011 at 5:34 pm #

    Interesting article on how Vitamin-D helped the Chicago Blackhawks hockey team make it to (and eventually win) the NHL finals:

    “Vitamin D Powers Chicago Blackhawks to Stanley Cup Finals”

  8. Glenn 19 May 2011 at 11:24 am #

    I used a SAD light off and on this winter and found that it helped me continue improving athletically…


  1. Weekend Link Love - Edition 141 | Mark's Daily Apple - 8 May 2011

    […] the Primal Lifestyle by visiting the Primal Blueprint 101 page. Thanks for visiting!Dr. Briffa presents the case for vitamin D as an athletic performance enhancer, calling it “solar power.” […]

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  3. Vitamina D e a Performance Atlética | Vida Primal - 9 June 2011

    […] Agora que você já sabe o que é, para que serve e como obter a vitamina D, podemos começar a ver alguns resultados relacionados a ela, como a evidência ligando a performance atlética aos níveis de vitamina D no organismo. Este post é baseado no seguinte, pelo Dr. John Briffa: ‘Solar power’ for human beings […]

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