Daily Dose of Sunshine

The benefits of D-lightful Vitamin D

Vitamin D, often referred to as “the sunshine vitamin,” is essential for human health. However, an estimated 85% of people in the U.S. are vitamin D deficient. Considering that our primary source of D is the sun, it’s not that difficult to come by in Central Oregon, especially during the summer. All you need is a little know-how to ensure you’re receiving enough of this intriguing and vital nutrient.

Vitamin D’s primary functions are to maintain proper bone structure and normal blood levels of calcium and phosphorus in the body. Dr. Julie Hood Gonsalves, professor of human biology at Central Oregon Community College in Bend, explains that even if you eat foods that contain a lot of calcium and phosphorus, without enough vitamin D, your body can’t absorb them. “Vitamin D helps the body absorb calcium from the digestive tract, it keeps the body from releasing too much calcium from the kidneys, and it takes calcium out of the bones if we need it in the blood,” she says.

But vitamin D is more than just calcium’s wingman. Nearly everything your body does relies on vitamin D. It helps your body’s cells to communicate properly, it maintains a strong immune system, reduces inflammation and plays a key role in keeping muscles, heart, lungs and brain working well. Current research also suggests that vitamin D may help protect against hypertension, multiple sclerosis, Alzheimer’s disease, diabetes and some types of cancer.

Vitamin D deficiency, on the other hand, is linked to rickets (soft, weak bones) in children and osteomalacia (thinning bones and weak muscles) in the elderly, and results in your body working far below its potential. In the past few years, studies have shown that vitamin D deficiency may be the primary culprit of depression, birth defects, asthma, heart disease and skin cancer.

Unfortunately, however, Vitamin D deficiency continues to rise. Why? One reason is that very few foods naturally contain vitamin D, and consuming foods that are artificially fortified with vitamin D is inadequate in supplying your body with the amount of D it needs. But other, bigger reasons are also the easiest to mitigate—people now tend to spend more time indoors, avoid the midday sun and apply sunscreen before sun exposure.

More than 80% of your body’s needed supply can be created through exposure to sunlight—UVB rays, to be precise. On average, your body can produce 10,000 to 25,000 IU of vitamin D from about 30 minutes in the sunshine. The necessary exposure time varies with age (as you get older your skin doesn’t make as much vitamin D in response to sun exposure), skin type (fair skin produces vitamin D more quickly than darker skin), season, time of day, altitude, latitude and environmental factors. “Allowing your face and arms to be exposed to the sun for 15 minutes several times a week is beneficial, especially between the hours of 10 a.m. and 3 p.m.,” says Gonsalves.

But try not to wear sunscreen for those short periods of sun therapy. Sunscreen impedes vitamin D synthesis by reflecting UVB light. If you plan on staying out longer than fifteen minutes, apply a sunscreen of SPF 8 or higher after you’ve soaked up the sun for a quarter-hour, wear protective clothing, or find a shady spot to relax in. Vitamin D is the goal; skin cancer is not.

Unfortunately for those of us in Oregon, a state that sits well north of the 40th parallel, it’s nearly impossible to get enough vitamin D from the sun alone in the wintertime, when the sun is low in the sky, and the UVB rays skitter off the top of the atmosphere like billiard bank-shots. But good news for Central Oregon: our higher-than-average elevation of more than 3,000 feet means there’s less atmosphere above us to interfere, so there’s a better chance that more UVB will punch through to reach our D-hungry bodies below. And our bluebird skies result in more sunny days in general. “In Central Oregon, we are on the ‘edge’ of the latitude considered to be a problem, but our altitude and amount of sun help to minimize that problem,” says Gonsalves.

If you’re a fan of skin care and geometry, the U.S. Naval Observatory provides a website that calculates the altitude and azimuth of the sun in your area so you can determine the best times and days of the year to receive free D from the sky. A good rule of thumb: if your shadow is longer than you are tall, you’re probably not making much vitamin D.

The good news, says Gonsalves, is that vitamin D is fat-soluble, so it gets stored in your fat tissue and liver to be released into your body when you don’t get enough from external sources. Healthy individuals can typically store around three months’ worth of vitamin D in their bodies to assist them as they “hibernate” through the winter months. But just to be safe (and because we have such long winters here in the high desert), taking a D3 supplement is advised during the wintertime—just don’t overdo it. How much vitamin D is necessary to the body is still under debate. In terms of supplements, “4000 IU a day is considered the ‘safe upper limit’ for adults,” Gonsalves says. “It’s important to know that more is not always better. Taking too much may cause side effects, including depositing calcium in soft tissue and possibly leading to kidney stones and atherosclerosis.”

Just another reason to soak up the Central Oregon sun! There’s no D-nying it, vitamin D is vital to your wellbeing.

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