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benefits Reflex Nutrition vitamin d vitamin d3

The single aim of this article is to bring together everything you need to know about Vitamin D and why it’s so important, especially if you are an athlete. I want you to be armed with all of the facts relating to how Vitamin D levels effect muscle growth, the immune system and more.

Perhaps of more importance is understanding how to achieve, what is believed to be, optimal Vitamin D levels. To do so will require a blood test and I will describe a very easy test that can be done at home with a simple kit supplied via the NHS.

Vitamin D and Muscle Strength

It might seem strange that a vitamin can have an impact on strength and muscular growth, but it’s important to realise that Vitamin D is actually a type of hormone and has numerous roles within the human body; some of which are still being discovered. Numerous studies are now showing how it can play quite a significant role for anyone in involved in sport. I’m going to summarise three recent studies that are of particular interest because they highlight very positive outcomes with supplemental vitamin D.

  • 1st Study: Effects of vitamin D supplementation on upper and lower body muscle strength levels in healthy individuals. A systematic review with meta-analysis. 2014. In this study the authors looked at a number of previous studies to determine whether or not Vitamin D effects muscle strength, their findings are summarized here: Vitamin D3 supplementation improves upper and lower limb muscle strength in a healthy, adult, athletic and non-athletic population between the ages of 18 and 40”
  • 2nd Study: 1,25(OH)2-vitamin D3 enhances the stimulating effect of leucine and insulin on protein synthesis rate through Akt/PKB and mTOR mediated pathways in murine C2C12 skeletal myotubes. 2013. In this study the authors looked at the effect of Vitamin D in relation to protein synthesis, the studied showed that increasing levels of Vitamin D increased the anabolic activity of L-Leucine.
  • 3rd Study: Vitamin D status and biomarkers of inflammation in runners.2012. In this study the findings were again very easy to interpret, the runners who had higher blood levels of Vitamin D had lower levels of TNF-a, blood marker for inflammation.

Just looking at those three studies give a very clear indication of the importance of Vitamin D if you are involved in sport. It will come as no surprise to here that numerous professional sports teams and athletes are taking full advantage of these findings to optimise their training results. If we look at the scientific studies relating to Vitamin D and its general role in health and the immune system we see a similar story. Again I’ll highlight three recent studies;

  • 1st Study: Vitamin D and mortality: meta-analysis of individual participant data from a large consortium of cohort studies from Europe and the United States 2014. The subjects with low levels of 25-hydroxy-vitamin D in their blood were 1.57 times more likely to die than the subjects who had high levels of vitamin D in their blood.
  • 2nd Study: Higher serum vitamin D concentrations are associated with longer leukocyte telomere length in women. 2007. Quote “Our findings suggest that higher vitamin D concentrations, which are easily modifiable through nutritional supplementation, are associated with longer LTL, which underscores the potentially beneficial effects of this hormone on aging and age-related diseases”
  • 3rd Study: Vitamin D3 supplementation in patients with frequent respiratory tract infections: a randomised and double-blind intervention study. Quote “Our data indicate that vitamin D3 supplementation reduces the odds of taking antibiotics by approximately 60% in patients with frequent respiratory tract infections.”

The scientific evidence supporting the role of Vitamin D in human health is growing month by month, the evidence is now so strong that EFSA, European Food Safety Authority, has concluded, “The Panel concludes that a cause and effect relationship has been established between the dietary intake of vitamin D and contribution to the normal function of the immune system and healthy inflammatory response, and maintenance of normal muscle function.”

So it’s clear that everyone can benefit one way or another from Vitamin D which leads me onto the part of the article where you can do something if you haven’t already to optimise your own levels.

What is the theoretical optimal level of Vitamin D?

Well it’s now widely accepted that obtaining blood levels of 25 (OH)D from 50-60 ng/ml is theoretically optimal based on current scientific studies. Sun exposure increases Vitamin D levels and that’s the human body’s way of making it. However for those of us living in the U.K and Northern Europe that’s simply not a possibility year round for obvious reasons. Further we are told now to stay out of the sun and wear high factor sun cream which effectively halts the body’s ability to make Vitamin D.


I suggest that most people will need to start with the bare minimum of 1,000 IU or 25ug of Vitamin D3, this can be found for example in our multivitamin Nexgen. You’ll find double that in Nexgen PRO and we also manufacture a standalone Vitamin D3 supplement with 2,000 IU / 50ug per capsule.


The best ways to achieve theoretically optimal levels are done by taking a 25-hydroxy Vitamin D2 and D3 test. I personally take 2 or 3 tests a year to absolutely guarantee I’m achieving my desired range and I have used the NHS. The test is very simple and is done at home. You are sent a small kit that uses a small piece of blotting paper to take samples of blood from one of your fingers. I’m more than happy with the service and the quality of the test that they undertake.

When you get the results back they are measured in nmol/L and this figure needs to be divided by 2.5 to get the results in ng/ml. A result from my test was 142.3 nmol/l which equates to 56.92 ng/ml, this is now about my average which is about right. To achieve this I use Nexgen PRO and I take 1 additional Vitamin D3 capsule. But that’s me, I do spend more time outside during the summer but I’m usually covered wearing a wetsuit if I’m kitesurfing and if I’m on my mountain bike shorts/t-shirt. But I’m not into lying around in the sun so even during the summer my exposure is quite limited. I took a test at the end of August in 2013 believing that my results would be higher than normal, they weren’t they were in the low 40s ng/ml. I therefore take 4,000 IU per day year round.

You’ve got your Vitamin D Results What Next?

Your next step will be a visit to the Vitamin D council, a non profit organisation with a sole purpose of highlighting Vitamin D. The link below will take straight to a table that details how much extra Vitamin D you will require once you’ve got your results. In addition their site is an extremely rich source of additional information. If you take a look at the following link it will answer many questions;



Hopefully you been to the link above and spent quite some time looking at all of the information that the site provides. If you, like me, take your health seriously it makes perfect sense to ensure you are getting enough Vitamin D, especially if you are highly active.

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