Springtime means more sunshine, and that means more access to the sunshine vitamin, vitamin D.
We’ve known for some time now about the importance of vitamin D, but to understand that it plays a role in up to 2,000 genes and in every single tissue and cell of everyone is mind blowing. There can be a downside to this, however, because 75 percent of American teens and adults don’t get enough vitamin D. That’s serious, too, since we need vitamin D to remain healthy at the cellular and genetic levels.
To review, vitamin D comes in two forms: vitamin D2 and vitamin D3. Vitamin D2 is made in plants, while vitamin D3—a highly studied form—is made when cholesterol in our skin cells reacts with sunlight. One more clarification: it’s called vitamin D, but it’s actually a powerful steroid hormone that gets around in the body’s cells and tissues to make sure all is well.
Dr. Michael Holick, a professor of medicine, physiology and biophysics who’s been studying vitamin D for over 30 years, says, “Every tissue and cell in your body has a vitamin D receptor. We estimate that as many as 2,000 genes are directly or indirectly regulated by vitamin D.”
By the way, Dr. Holick knows that most folks don’t get enough vitamin D, so he recommends taking 2,000IU of vitamin D daily for adults and 1,000IU daily for teens and children aged 1+. Other experts on vitamin D recommend even higher daily intakes of the sunshine vitamin—anywhere from 4,000IUs to 5,000IUs.
Dr. Anthony Norman, professor of Biochemistry and Biomedical Sciences at the University of California Riverside, agrees on the essential functions of vitamin D in the body. He says, “Vitamin D supports immune system, pancreas, heart, blood, cellular, muscle, bone and bone marrow, breast, colon, intestine, kidney, lung, prostate, retina, skin, stomach, uterine and brain health—and can impact 36 bodily organs.”
That’s great news about the health benefits of vitamin D—but only for the 25 percent who get enough of it. That concerns me, too, because coming up short on vitamin D causes vitamin D receptors in our bodies to not activate, failing to protect us. For example, vitamin D supports immune health, including our T cells, which help our immune system respond quickly to unwanted invaders. What activates T cells, however, is vitamin D. Without it, T cells are inactive—with no immune response—as invaders attack.
It’s a similar story for the other vitamin D receptors found in our cells throughout the body.
Why the shortfall, though?
There are many reasons why people don't get enough vitamin D. For example, older people make less vitamin D than younger people do when exposed to sunlight. Speaking of sunlight. . . SPF 8+ sunscreens reduce vitamin D production by 95 percent, while complete cloud cover reduces UV energy by 50 percent. Shade and smog slow down UV energy by 60 percent.
Additionally, if you live north of an imaginary line that stretches from the northern border of California to Boston, then the ultraviolet energy is not enough for vitamin D synthesis for four to six months out of the year.
Then there are those who avoid the sun altogether.
Add that to our diets which typically don’t provide enough vitamin D, and it’s no wonder there’s a shortfall.
Here’s the bottom line: Vitamin D really is a hot, must-have vitamin that our bodies need to be healthy at the basic level, so make sure you get enough.