Vitamin D Day!
One of the hot topics in the sports nutrition and health world at the moment is Vitamin D. With this in mind I thought I would write my views and supplementation protocols on this ‘wonder vitamin’.
When I first started reading about Vitamin D, for some reason all I could remember from my days studying Biology at school were the graffitied images in the school textbooks of the people with rickets. What comes to mind for you? Nearly every tissue and cell in our body has a vitamin D receptor, which is why positive nutritional status of this vitamin is essential in our modern diets.
Besides the famous deficiency disease, ‘Rickets’, low vitamin D levels have often been associated with osteo conditions such as deformed bones, retarded growth, osteoporosis, spontaneous fractures and tooth decay. This is mainly due to the fact that without enough activated vitamin D in the body, dietary calcium cannot be absorbed. Calcium is essential for signalling between brain cells, development of bone, and tooth formation.
However, long term deficiency may have more implications for other ailments including: – Rheumatoid arthritis – Inflammatory bowel disease – Multiple sclerosis – Diabetes – Certain cancers – Fibromyalgia like symptoms – Poor blood sugar regulation
These are some pretty big issues that one vitamin’s deficiency can have an effect on! The scary fact of the matter is that ‘Vitamin D deficiency is a highly prevalent condition present in approximately 30% to 50% of the general population’
These are big issues, but near about everything seems to cause illness and disease these days!
I know, I know, it seems that more and more people are scaremongering people into diet change and supplementation protocols. Many are even suggesting that people will get all of the above if you don’t change.
This is not my style!
With this in mind I thought I would share the key benefits that adequate intake of Vitamin D can have to you as an individual. Numerous studies have shown positive effects on longevity, performance and aesthetics when vitamin D is returned to its intended levels:
– Melamed, et al. found that total mortality was 26% higher in those with the lowest 25 hydroxyvitamin D levels compared with the highest. And a meta-analysis of 18 randomized controlled trials found that supplemental vitamin D significantly reduced total mortality.
– Russian studies in the 1930’s showed that 100M dash times improved in irradiated athletes vs. non-irradiated athletes undergoing the same training (7.4% improvement vs. 1.4%).
– German studies in the 1940’s showed that irradiation lead to a 13% improvement in performance on the bike ergometer vs. no improvement in the control group. – Dr. Shalamar Sibley’s new research shows that adding Vitamin D to a reduced-calorie diet may lead to better, faster weight loss. Not only did she find that excess body fat came off faster when plenty of D3 was present, but it also came off the abdominal area. The same D-supplemented subjects retained muscle mass while losing the fat.
How much Vitamin D should I be aiming for?
What really matters to us is our circulating 25 hydroxyvitamin D concentration. It lets us know how much vitamin D has been produced in our body from sun, food and supplements. Its half-life is 15 days. This status can be obtained via a blood test performed by a doctor. 1,25 dihydroxyvitamin D status is another test that can be obtained but is not a good indicator of vitamin D status, as it has a short half-life of only 15 hours and levels in the blood are regulated tightly by hormones and minerals. 1,25 dihydroxyvitamin D only starts to decline when a severe deficiency of vitamin D is present.
The Vitamin D Council suggests that an average individual should shoot for blood levels between 50-80 ng/mL. ‘The average person in late winter averages about 15 to 18 ng/ml, which would be considered a serious deficiency.’
The big question I am sure you are asking yourself is, ‘where can I get more vitamin D?’ Vitamin D is found in small amounts in eggs, mushrooms, liver and oily fish such as salmon, sardines and mackerel. Fortified milk and cereal will also contain a bit, but this has often been added artificially to non-ideal food sources for those looking for body composition change.
Despite all of this, those who wish to maximise the benefits of a higher Vitamin D intake for their health, longevity and performance would struggle to obtain enough through food sources alone, which is where a vitamin D supplementation regime would come in use. The other major source of vitamin D is sunlight. Vitamin D is the only vitamin which can be obtained in this way!
‘The basic intake guidelines are: 5-30 minutes of sun exposure between 10am and 3pm at least twice a week without sunscreen. The effectiveness of such a procedure however depends on where you live, the pollution levels, cloud cover, age, the season of the year, your natural cutaneous melanin content, etc.’
Guidelines for restoration
I am not a supplement pusher by any standard. I do not sell supplements. I will also only recommend supplements to people that I have a) tried myself and b) have faith in.
When looking for a Vitamin D supplement, choose the D3 form. You can obtain these in gel cap or liquid form depending on preference. Since D is fat soluble, I would recommend taking them with foods containing a little fat to optimize absorption. Polyunsaturated and monounsaturated fatty acids are best.
There is a lot of range in the recommended dosages that experts believe will benefit the average person, but 5000IU per day seems to be the best recommendation for the greatest benefit.
Of course, be sensible and do talk with your doctor before beginning any supplementation protocol. For those more interested in natural means of obtaining positive vitamin D status: 15-30 minutes of mid-day sun (15 for those with lighter skin, 30 for darker) between March and October can help for those living around London. In the depths of winter however, supplementation would definitely be recommended.
Scott Marsh – Beaconsfield Personal Trainer http://www.xceleratefitness.co.uk
Lee et al, (2008), ‘Vitamin D deficiency an important, common, and easily treatable cardiovascular risk factor?’, Journal of the American college of cardiology, December 9;52(24)
Shugart. C, (2009), ‘D’ is for Doping’, [Online], Available at: http://www.t-nation.com/free_online_article/sports_body_training_performance_nutrition/d_is_for_doping. [Accessed 09/08/2011]
Andrews. R, (2009), ‘All About Vitamin D’, [Online], Available at: http://www.precisionnutrition.com/all-about-vitamin-d. [Accessed 09/08/2011]