Vitamin D and Sports Performance
We’re experiencing an epidemic of Vitamin D deficiency. It is estimated that 1 billion people worldwide live with low Vitamin D levels, which can cause many problems in the body.
This especially applies to athletes, where Vitamin D plays a critical role in the health and athletic ability of an individual, regardless of their sport.
Today, we’ll explore the role of Vitamin D in the body, what it means to be Vitamin D deficient, and its effect on Sports Performance.
The Role of Vitamin D in Athletes
The role of Vitamin D goes much further than you might think.
The role of Vitamin D
Vitamin D plays a vital role in an athlete's health and performance. Here's a breakdown of its key benefits:
Bone health: Vitamin D helps regulate calcium absorption, which is crucial for strong bones and muscles. Deficiency can increase the risk of stress fractures and muscle weakness.
Immune function: Vitamin D supports a healthy immune system, potentially reducing the frequency and severity of illnesses that can derail training.
Muscle recovery: Some research suggests that sufficient Vitamin D levels may improve recovery after exercise.
Muscle function: While evidence is developing, low Vitamin D status may be linked to decreased muscle strength and performance.
Approximately 5% of your genes are impacted by Vitamin D. Emphasis on the word “impacted” because that’s exactly what it means. Vitamin D doesn’t directly impact your body, but it rather sends signals to regulate other nutrients such as calcium and phosphate.
An adequate amount of Vitamin D is required for the development, growth and integrity of bones. But how do you know if you have an “adequate amount” of Vitamin D?!
How to know if you are Vitamin D deficient
Individuals with Vitamin D deficiency are often misdiagnosed with other conditions such as rickets and fibromyalgia, emphasising the need for a deeper awareness and understanding of the micronutrient.
Let's start by defining what it means to be Vitamin D deficient. Is the answer for optimal Vitamin D levels as clear as black and white, or is it grey?
It’s important to note that it is still a grey area even at the pinnacle of Sports Science. No one can pinpoint a definitive answer on how much Vitamin D is optimal. However, there are years of studies that relate patterns of Vitamin D deficient symptoms and sufficient benefits.
According to the Office of Dietary Supplements, Vitamin D levels can be measured by the 25-hydroxy level in nanomoles/litre (nmol/L) or nanograms/millilitre (ng/mL). You can get tests online or through the support of medical professionals.
It should go without saying but if you’re going to get a test from the internet, just make sure it is approved by your national governing bodies.
The results of your test using these measures can be indicated by the following:
Deficiency: <30 nmol/L or <12 ng/mL
Inadequate: 30 to <50 nmol/L or 12 to <20 ng/mL
Adequate: ≥50 nmol/L or ≥20 ng/mL
Too high: >125 nmol/L or >50 ng/mL
Both ends of the spectrum can offer their negative consequences. For example, people with Vitamin D levels below 30 nmol/L can experience severe symptoms such as osteoporosis, osteomalacia, and other immune deficiencies.
If Vitamin D levels are persistently low, then potential underlying issues might chronically elevate blood glucose, inflammatory levels, visceral body fat, or gut dysfunction.
But getting too much Vitamin D won’t do you any good, either. Measures above 125 nmol/L can lead to symptoms such as nausea, vomiting, weakness, and frequent urination.
Although there isn’t a universally agreed “optimal” daily dose of Vitamin D, between 400 IU and 800 IU (or 10mg to 20mg) daily is a good target to aim for.
What happens in the body when we get Vitamin D?
When Vitamin D enters your body, it is exerted in two pathways - the genomic pathway and the non-transcriptional signalling pathway.
The genomic pathway modifies the transcription and translation of the target genes. This shows that Vitamin D promotes the increase of muscle cells and differentiation.
The non-transcriptional signalling pathway associated with the membrane is where the receptor for 1.25-OHVITD is located. It has been shown that this mechanism enhances the interaction between myosin and actin in the sarcomere, making the force of muscle contraction stronger.
Vitamin D first enters the liver where it gets converted into 25-hydroxy Vitamin D (the measurement used when testing for Vitamin D levels).
When you get Vitamin D, you increase your body’s:
Ability to synthesise muscle proteins
Concentration of adenosine triphosphate (ATP)
Ability to perform aerobic (light jogging) and anaerobic exercise (high-intensity speed work).
How to get more Vitamin D
If you’re trying to obtain enough Vitamin D through diet alone, you’ll face an endless uphill battle. Only a few foods contain the necessary amount of Vitamin D.
Although it may seem that elite-level athletes have the perfect nutrition, micronutrient deficiencies are common. Getting more Vitamin D through supplementation and diet should be individually prescribed based on the athlete's factors (training intensity, duration, etc.).
Here’s how to get more Vitamin D:
Sun exposure - the most natural and abundant source of Vitamin D is the big bright thing in the sky - sunlight. This will be much easier to get access to if you’re in a hotter climate, but for some countries (like myself, in England), it can be challenging to depend on the sun for Vitamin D, especially in the winter months. This puts even more emphasis on promoting an outdoor lifestyle.
Food sources - foods such as fatty fish, mushrooms, and eggs are all good sources of Vitamin D. Cod liver oil is also a good option.
Supplementation - the easiest way to track exactly how much Vitamin D you’re getting is through supplementation.
It should go without question that the best way to get more Vitamin D is through sunlight exposure.
Studies show that Vitamin D supplementation benefits neuromuscular and aerobic performance. “In a randomised placebo-controlled trial, the effect of vitamin D (5000 IU per day over eight weeks) on speed times and vertical jumps in a cohort of athletes was evaluated. The group that received Vitamin D supplements recorded a substantial increase in vertical jump heights from the beginning to the end of the study period, while no change was observed in the placebo-controlled group.” (Jones G. Pharmacokinetics of vitamin D toxicity. Am J Clin Nutr. 2008 Aug).
Recap
To recap, the issue of Vitamin D deficiency affecting approximately 1 billion people globally is a cause for concern, given its crucial role in the body. Despite the perceived health of athletes, this concern shouldn’t be neglected with Sports Performance, where Vitamin D is instrumental in an athlete's health and overall athletic ability.
From maintaining bone health and supporting immune function to influencing protein synthesis and cardiovascular health, the contributions of Vitamin D show its significance.
Recognising the challenges of determining optimal Vitamin D levels, it is imperative to address deficiencies by testing. Striking a balance is key, with both deficiency and excess presenting unique challenges.
To enhance Vitamin D levels, a combination of sunlight exposure, dietary sources, and supplementation tailored to your individual needs is recommended.
As studies show the positive impact of Vitamin D on performance, its role extends beyond bone health to influence neuromuscular and aerobic capabilities, making it a crucial component of holistic health and athletic excellence.
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If you would like any extra support with Vitamin D, please explore my coaching services, or contact me directly!
