Supplementation of nutrients seems so controversial amongst medical/naturopathic/fitness professionals and enthusiasts. You have probably heard/read things like:

  • Supplements are expensive urine.
  • They’re not regulated by the FDA.
  • This is the best fat burner… proceeds to point at CLA (eye roll)
  • You don’t need Vitamin D, just eat a balanced diet and get sunlight!

Well….those statements are predominantly FALSE + Wtf is a balanced diet..? Asparagus spears in one hand and a brownie in the other? Although, the sunlight statement is true-ish, which leads us to the article’s topic: Vitamin D.


What is Vitamin D?

Vitamin D is a fat soluble vitamin (one of the 24 essential micronutrients) that is produced by exposure to sunlight. Vitamin D is actually one of the few vitamins we (humans) can produce depending on our exposure to sunlight. It is estimated that somewhere near 1 billion people are deficient or have some sort of vitamin D insufficiency [1]. One study found that 88.1% of participants were insufficient [2]. For the sake of background knowledge, here is a quick physiology primer on Vitamin D3 synthesis:

  • Bare skin comes in contact with ultraviolet B rays and pre-vitamin D is produced [3].
  • Pre-vitamin D attaches to a binding protein that is then transported to the liver [3].
  • Once in the liver, it is converted to calcidiol and is making itself available for tissues that need it (this is what is measured by doctors) [3].
  • When the kidneys or tissues (brain, immune cells, cardiac muscle, etc.) need vitamin d, it is converted to calcitriol (hormonally active form) and is ready to be used [3].
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