The sunshine vitamin
D promotes strong bones, good mood, better health
BY BARBARA FABER, APNP
Ministry Medical Group
A recent study, based on data gathered through the National Health and Nutrition Examination Survey, concluded that more than 75 percent of Americans were Vitamin D deficient in 2014, up from 55 percent who were deficient just a decade earlier.
As the researchers pointed out, the magnitude of the decline over such a short period was “surprising.” Yet medical experts are still divided regarding the significance for overall health.
The Institute of Medicine (IOM), on the other hand, defines deficiency, in terms of bone health, as less than 20 nanograms per milliliter. And at least some of the decline in Vitamin D levels, according to the IOM, may be due to changes in the test used to measure blood levels.
Even with the lower threshold, defined by the IOM, about 10 percent of Americans would be classified as deficient–a significant number.
Rickets, an extreme Vitamin D deficiency that causes short stature, bowed legs and other bone deformities in children, is now rare.
Osteoporosis is a common problem among postmenopausal females and older males. Symptoms of a deficiency that might go unnoticed include unexplained fatigue, muscle weakness, bone pain and frequent fractures.
The role of Vitamin D in building and maintaining strong bones is undisputed. Vitamin D promotes absorption of calcium into bones.
Vitamin D receptors exist in every tissue of the human body, including the heart, brain, muscles and immune system. And numerous studies have linked Vitamin D deficiency to a range of potential health problems.
Persons with low levels of Vitamin D tend to have a higher prevalence of hypertension, high cholesterol and cardiovascular disease. At least one reason may be the anti-inflammatory effects of the vitamin. The prevalence of multiple sclerosis and breast, colon and prostate cancer is lower in sunny areas near the equator than in more northerly climes.
The problem is that most of these studies are observational, showing associations and trends but not necessarily establishing cause and effect. The Institute of Medicine report found the evidence regarding benefits of Vitamin D beyond those of bone health to be unconvincing and called for more randomized, controlled studies. And studies that have been conducted so far have produced mixed results. As one expert pointed out, though, lack of randomized trials does not necessarily mean lack of benefit.
Foods that are naturally high in Vitamin D include fatty fish such as salmon and tuna, beef, cheese, egg yolks and mushrooms. Milk, yogurt, orange juice, margarine and many breakfast cereals are fortified with vitamin D.
It’s difficult, though, to get adequate quantities of the sunshine vitamin without spending some time in the sun–another area of controversy.
One reason for the recent decrease in Vitamin D levels is undoubtedly related to legitimate concern regarding ultraviolet radiation, a major cause of skin cancer and premature skin aging. UVB, though, is also crucial to stimulating Vitamin D production and rays will not pass through your living room window.
Seniors are unlikely to be spending an afternoon at the beach or sun bathing in the back yard. But many doctors consider it important for them to get about 5 to 10 minutes of sun exposure, without sunscreen, several days a week. In cloudy, northern climates, that is not always easy. But it’s good for your bones; it’s good for your mood; it’s good for your overall health.
Barbara Faber, APNP is a Nurse Practitioner with Ministry Medical Group, part of Ascension.