Wednesday, November 8, 2017

Vitamin D Deficiency: The Invisible Health Challenge By Rachel Zambrano

Vitamin D – An Introduction

As an athlete and a multi-sport endurance coach, I’ve learned that there is so much more to sports than just the workout. Nutrition and health are arguably the foundation of the athlete but with perhaps the least focus. Every aspect of the well-tuned athlete comes back to wellness, whether professional or amateur and yet, there’s so much that doesn’t get the attention it deserves. We, as athletes and coaches, joke somewhat truthfully about how we ride because we love to eat, or we run because the road is a good listener, but it’s these motivations that, if they remain an afterthought, threaten to derail the best training of talented athletes.

Vitamin D may seem like a strange topic of conversation for fairly healthy athletes, but a recent conversation with an athlete, in turn, spurred a conversation with my physician.  Once I started digging a little deeper, I realized that vitamin D levels have significant implications for athletes at all fitness levels.

Vitamin D plays an important role in maintaining good health.  For most of us, it seems something we seldom consider except as just another vitamin/supplement we all find in a dizzying array in our local grocery store or chain pharmacy. It is vitally important that we consider if we have sufficient Vitamin D levels due to the fact that most of us don’t get enough sun on exposed skin throughout the week.
Many adults are vitamin D deficient, and if the data is credible, the numbers top more than a billion people worldwide (1)

My experience with this was limited until that athlete suggested that I get my own Vitamin D levels tested.  What information I initially found was not particularly well organized nor was it very helpful. On the other hand, knuckling down and combing the research, I realized that the information I was reading was important for other athletes to see, and that they should also have access to a summary of why it is so important.  So… let’s start at the beginning.

The Beginning – Where Vitamin D Comes From:

Vitamin D comes from two sources: it can be synthesized when UVB light from the sun’s rays strikes the skin, or it can be taken in by diet.13 Unfortunately, wearing sunscreen can reduce production of Vitamin D by up to 95% percent 2, and if you’re like me (fair skinned), the sun might as well be kryptonite.  It is estimated that 50-90% of our Vitamin D comes from sunlight (8).

The Middle – What Vitamin D does for the body:

Vitamin D is required to properly absorb dietary minerals like calcium and phosphorus in order to provide us with effective healthy bone turn over, without it, we can end up with problems – Rickets being a classic from history, with Vitamin D deficient children ending up with bow-legs

In addition to the obvious bony pathology, evidence-based studies suggest  Vitamin D actually widespread effects on the body.  Thus it is easier to describe Vitamin D by disease and the impact of Vitamin D deficiency on that particular disease, rather than a list of possible changes:

  • Vitamin D allows for better absorption of calcium in the body
  • Insufficient Vitamin D levels stimulate parathyroid hormone synthesis, resulting in the body potentially pulling calcium from the bones, essentially thinning the bones, increasing the risk of fracture


  • Epidemiological data showing serum values show an inverse relationship between incidence of cancer and Vitamin D for prostate, colon, breast, lung and marrow/lymphoma, among others – across several human and animal studies

Infection and Immune Response

  • Studies have indicated that the body is better able to fight off infection when Vitamin D levels are optimal


  • One Finnish study indicated the prophylactic effect of Vitamin D supplementation during the first year of life against diabetes later in life
  • Studies indicate Type I and II diabetes are associated with low Vitamin D levels

Hypertension/Cardiovascular Disease

  • Vitamin D levels and hypertension are strongly associated
  • Myocardial infarction risk varied inversely with Vitamin D levels (3)
Other sources indicate fat-soluble vitamins (Vitamin A, D, E)  are related to hair and nail strength. Vitamin D is also an important part of the discussion when it comes to mental health, but seasonal depression is the most obvious effect of insufficient Vitamin D levels (9). Studies in the last decade indicate that there is a positive relationship between pregnancy health and Vitamin D levels, suggesting most women would benefit from supplements during this time. Now that we’ve covered the medical part, let’s get down to why it’s important to you and me as athletes.

Read the full article by PCG Coach Rachel Ruby Zambrano at Titanium Geek