Vitamin D is everywhere. You hear about it on the news, in magazines, even right here on EmpowHer.com. Some tout it as the new super vitamin, yet why are so many Americans deficient? It is fortified in milk, bread, cereals, and the sun right above our heads (unless you live in Portland like me) yet studies show even those living in the brightest spots are not receiving enough.
So let’s review. . .What is Vitamin D?
First of all, it is a fat soluble vitamin that is metabolized by ultraviolet light (particularly UVB) or from our diet. Vitamin D is taken into our liver where it is converted into 25(OH) Vitamin D3 (calcidiol) which is the major form in our body and the kind that we test. To become biologically active, it goes through an extra step in the kidneys where it turns into 1,25(OH) Vitamin D3 (calcitriol). This active form only hangs around for about 6 hours where as the testable form remains up to 2 weeks. Additionally, once activated, Vitamin D becomes a hormone.
But, Dr. Jones, I am a sun-bunny! I live for its warmth and love to be tan. Of course, but sunscreen with a SPF 8 and above eliminates 93-99% of your vitamin D absorption. This is why those living in Florida and southern California are depleted. The same holds true for people with darker pigmented skin. Melanin blocks absorption as well.
What does it do?
1) Vitamin D has a major role in calcium and phosphorus balance. This, of course, means we need enough to improve bone health, reduce fracture risk, and reduce bone pain.
2) It helps your body manage an autoimmune disorder such as rheumatoid arthritis, multiple sclerosis, lupus, and others.
3) There are receptors in the heart muscle so it improves heart contractions and vascular tone. There are links to low levels and myocardial infarction risk.
4) It is important to your renin-angiotensin-aldosterone system which helps monitor blood pressure, electrolytes, and water balance in your body.
5) Vitamin D is potentially anti-cancer! There are receptors in your colon, brain, breast (and prostate for you male readers).