How It Works: Vitamin D Stands for Dem Bones, Dem Bones

By Jarrod Beachum, PA-C

Good morning sunshine! Our bones say hello! In this week’s How It Works blog, I wanted to talk briefly about Vitamin D. I was inspired to write this blog today because I am sitting in my office at home charting. I took a break and noticed my kids were glued to their iPads (no school today!) and looked out the window to see some beautiful weather. Of course, when I mentioned they should go outside and play, they said “I don’t wanna”. I mentioned they need to go get some Vitamin D, which garnered some puzzled looks. I was struck with an onslaught of questions like “what is vitamin D?”, “how does playing outside get us vitamins?”, and “can I have $20 bucks for Roblox?”. That last question was from Carter, and totally irrelevant. Anyways, I decided to make this a teaching moment for them and thought, hey, I need to write a blog this week, so why not write this up? (They were super excited to be included in this blog, and Carter only charged me $10 for use of his name, and Chloe got 10% for negotiating the contract). Here is How it Works: Vitamin D.

Vitamin D is calciferol, a fat-soluble vitamin that can be obtained from a few different foods, supplements, or from within our bodies, which is the most common source by far. When we are exposed to UV radiation, a chemical reaction occurs in the skin that converts 7-dehydrocholestorol into calciferol. It is stored in the fat cells. When it is needed, it is turned into calcidiol in the liver, and further processed in the kidney as calcitriol, otherwise known as Vitamin D3 (technically it is 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] but that is a mouthful to say). This is the active form that does all the work, including bone health, inhibiting breast/colon/prostate cancer progression, autoimmune protection, and more. I’m going to focus on “dem bones”, and show you how playing outdoors occasionally can prevent rickets in your kids (mine too). *Bonus factoid: SPF 15 sunscreen, while protecting our skin cells from cancer, reduces the rate of Vit D production by 99.9%! However, don’t skip on the sunscreen, as most dermatologists and endocrinologists agree that the risk of skin cancer outweighs the amount of Vitamin D we get from sun, especially in these days of Vit D-fortified foods and supplements. And no, tanning beds are not considered “taking your vitamins.” Nice try.

So now that we know how Vitamin D is made, lets look at how the body uses it to protect our bones. D3, again, is produced by the kidney. This process is tightly controlled by parathyroid hormone based on calcium levels in the blood stream. D3 is essential for absorbing calcium from our food in the large intestine and capturing free calcium and phosphate in the kidney before it can be excreted. When low calcium levels are detected in the blood, calciferol is released to be processed as I described above. With increased D3, more calcium will be absorbed from the gut, thereby increasing blood-levels of calcium and making the world right again. If it were not for adequate Vit D levels, the calcium would instead be pulled from our bones, as our bodies think it is more important to have it in the bloodstream than anywhere else (ok, that actually is important). Vit D deficiency makes our bones weak and brittle. In kids, this condition is known as rickets and results in softening of the bones, commonly seen outwardly as very bowed and weak leg bones. The similar condition in adults is called osteopenia (or osteomalacia), but the key difference is kid bones are still forming, and untreated can lead to life-long deformity and disability, among other complications in the rest of the body. For adults, our bones aren’t growing anymore so they just become very soft and weak, eventually progressing to osteoporosis.

If you would like to learn more about proper Vit D levels and use of supplements, come see me at 45 Urgent Care!