It’s been sunny (ish) for the last few days here in Portland. And maybe you’ve gone outside hoping to both enjoy the light and make some Vitamin D.
Sunshine by itself is great for you — it helps with sleep, improves mood, supports healthy weight, lowers blood pressure and more.
But I’ve got some bad news on the Vitamin D front: Depending how far you are from the equator, the sun’s angle may be too low for you to make any significant progress on your Vitamin D levels.
There’s an app I’ve talked about before, D Minder, that shows how much of the vitamin you can make at any particular time in any particular place.
One of the things I like about it is the part that says “Your next Vitamin D opportunity is in…” and then gives you a measure of time. Here in Portland, that time is measured in months starting sometime in November.
Why can’t you make Vitamin D when the sun is lower on the horizon? The app has a great video that shows this visually, but the short version is this: The sun’s ultraviolet rays have to travel through more atmosphere to get to our skin, and they’re not strong enough to trigger production by the time they reach us.
This is why so many of us need to supplement. If we don’t make enough Vitamin D in the summer, we become deficient (or more deficient) in winter.
We just shifted enough toward spring that we can now make Vitamin D from sunlight here in Portland — but still just tiny little bits of it. That leaves us still squarely in the supplementation zone.
What’s best for you? I’m a strong proponent of getting your levels tested. I see so many patients come in with their Vitamin D tanked, and we know how important it is for immunity, bone health, mood and more. Ask your doctor about checking your vitamin D, or make an appointment with me and it’ll be part of your full workup.
Salúd!
—Dr. Orna
P.S. If you’re interested in Vitamin D supplements, you can see my favorites at my virtual medicinary site.
Resources:
- The vitamin I’m asked about the most.
- The sun is more than just a vitamin.
- “Can You Rely on Sunlight to Get Enough Vitamin D This Winter?” from the Linus Pauling Institute at Oregon State University.
- “Environmental factors that influence the cutaneous production of vitamin D” from the American Journal of Clinical Nutrition.
- “Is Sunlight Exposure Enough to Avoid Wintertime Vitamin D Deficiency in United Kingdom Population Groups?” from the International Journal of Environmental Research and Public Health.
