Vitamin D levels can be low year round, but they can plummet during the fall and winter months due to lowered potency and amounts of sunshine, more time indoors and more. In some people, it can actually make them “SAD”—literally, with seasonal affective disorder, or SAD, which is caused by lack of vitamin D, according to The University of Maryland Medical Center. With SAD, some people get depressed or have depression worsen in the winter months when there’s a lack of sunlight.
That makes sense, too, because it’s nearly impossible to get adequate vitamin D from the sun in winter months for most of the country. Also, adequate vitamin D is required to produce enough serotonin—the body’s “feel good chemical”—in the brain. Walter Stumptf, with the University of North Carolina, determined through research that SAD could be addressed via vitamin D supplementation and using bright lights.
But SAD isn’t all the damage that dwindling D stores can cause. Bone pain; muscle weakness; bone and joint arthritis; severe asthma in children; increased risk of death from cardiovascular disease; increased cancer risk; cognitive impairment in older adults; type 2 diabetes; high blood pressure; glucose intolerance and more can all be seen as vitamin D levels plummet.
It’s no wonder there can be such fallout, however, because vitamin D plays a role in up to 2,000 genes and in every single cell and bodily tissue of everyone. Biochemistry and Biomedical Sciences professor at the University of California Riverside, Dr. Anthony Norman, 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.”
Since vitamin D is such a cornerstone to health, it’s easy to understand why getting enough of the “sunshine vitamin” would be of primary importance. Unfortunately, 75 percent of American teens and adults don’t get enough of this “hot” vitamin.
Why the “D”ficiency? There are many reasons for coming up short on vitamin D, including not eating enough vitamin D-packed foods over time to keep levels high. For example, following a strict vegetarian or vegan diet can limit vitamin D intake, since most natural sources of vitamin D, such as fish, fish oils, milk, egg yolks, cheese and beef liver, are animal based. Likewise, you may be underexposed to sunlight, which can be a problem, since the body makes vitamin D when the skin is exposed to adequate sunlight. If you’re inside most of the time, live in northern latitudes, wear long-sleeved shirts and long pants or use sunscreens, then you most likely don’t get enough sunlight to keep your D levels high.
Also, if you have dark skin, are older, are obese or have certain health issues, then you may be in vitamin D deficit as well. For instance, as people age, their kidneys lose some ability for their kidneys to convert vitamin D to its active form. Or, if you have an illness such as digestive unhealth, then your intestines may not have the capacity to properly absorb vitamin D from the foods you eat.
And since body fat can sequester vitamin D, children and adults who are obese require two to five times more vitamin D to prevent a deficiency. And get this: stress can also interfere with vitamin D levels. The stress hormone cortisol can inhibit vitamin D receptor functioning. So, it’s important to limit stress and to get high-quality sleep so that your body can readily use the vitamin D it has.
The bottom line is to take great care to avoid dwindling D damage. Keep those D stores up—especially during this time of year.