Vitamin D—You Absolutely Must Get It—Here is How
So you’ve heard vitamin D is essential to health, but it is not produced by your body—that you must get it from an outside source … you have heard that, right?
And you know that, while enriching milk with synthetic vitamin D may be helpful, it doesn’t solve the D dilemma . . . right?
Moreover, you’ve heard the latest on vitamin D—that your body needs it for much more than just bone health, that many (probably most) of us don’t get enough vitamin D and that the very best way to get your essential dose of just-like-nature-delivers-it vitamin D is by exposing your skin to sunlight.
Right? You’ve heard all of this?
Good. Here is the Dilemma:
In order for the reaction between your skin and UVB rays from the sun to produce the vitamin D your body so desperately needs, the sun must be higher than 50 degrees from the southern horizon—if you are in the northern hemisphere—and from the northern horizon, if you are south of the equator.
Depending on where you live, however, there may be times during the year when it is impossible to produce your own vitamin D—even if you stay out in bright sun all day long.
The approximate area of concern lies north of the 37th parallel. That is south of Denver and San Francisco … so, much of the United States and all of Canada are affected.
That means it is crucial for you to know exactly when to expose your skin to sunlight in order to get your vitamin D. If the sun is not above 50 degrees from the horizon, your efforts to generate vitamin D from it will be unsuccessful.
So how do you know when the sun is in the correct position?
If you happen to have a clinometer handy, determining the altitude of the sun is simple. The clinometer is an instrument that measures angles—and the angle you are looking for is the one formed by the “true” horizon (ground level) and the sun – to either the southern or northern horizon. If it is 50 degrees or more, expose some skin and make some vitamin D.
What if you don’t have a clinometer, though? You guessed it, there is a website for almost everything—and the one you are looking for is operated by the United States Navy. The web address is http://aa.usno.navy.mil/data/docs/AltAz.php.
Here is how it works:
- For the USA, use Form A
- Enter the date on which you want to make vitamin D
- Leave “Tabular Interval” as is
- Choose your state
- Enter your city
- Select “Compute Table”
That will take you to a readout consisting of three columns: Time, Altitude, and Azimuth. Look down the center column (Altitude) until you see the number there read 50 or more.
Record the time from the first column at that point. Keep looking down the chart until Altitude again drops below 50. Again record the corresponding time from the first column (the heading there is “h m” for “hour minute”).
You now have the information you need for the personal manufacture of the best vitamin D on the planet. Your job now is to expose your skin to the sun and let nature take its course.
How much sun do you need?
How long to stay in the sun depends upon how dark your skin is already, the altitude of the sun, whether there are any clouds, and how much skin you expose.
In general, one hour of soaking up those rays (break it up into at least two sessions), when the sun is at an altitude of over 50 degrees, should suffice. Use common sense, though.
Ease into it if you are fair-skinned. Don’t over do it. And, even though you should not wear sunscreen when you are making vitamin D, you should definitely use sunscreen at other times.
The sure way to know whether you are getting enough of the essential vitamin D is by having your blood tested. Ask your physician for information and advice.
And if you live in the northern part of the United States, the sun may never get above 50 degrees during the winter months. You can tell by plugging December 31st into the calculator on the Naval website and checking the altitude column.
That means there may be several months during the year when you need to rely on a supplementary form of vitamin D. A quality vitamin and mineral supplement will help, as will making sure to include foods containing vitamin D in your diet—things like salmon, tuna fish and egg yolks. D-fortified milk and milk products can be of some benefit as well.
One thing is for sure: You need vitamin D. How to get the sunshine vitamin?
Well, that is up to you, but I’m going to check the sun altitude table and go for a walk outside with my sleeves rolled up and my hat off during the time when the sun is above 50 degrees from the horizon. And if someone asks me where I’m going, I’m going to tell them, “Out to make vitamin D.”
- License: Image author owned
Lane Goodberry is a boomer-era writer focused on health, the environment and entrepreneurship. Lane is a champion of small business and everyday wisdom.