When you hear “Sunny D,” you probably think of the tangy beverage marketed to kids on morning television. Though the company claims to be a healthful drink, or as their commercial says, “good stuff kids go for,” 8,000 liters of the “good stuff” leaking out of their production plant, killing dozens of fish, belies that assertion (Google “Fish killed as soft drink leaks from factory” for the full story).

It’s too bad “Sunny D” doesn’t garner thoughts of what it rightfully ought to: the sun being the best source for vitamin D.

I’ve written extensively on the importance of vitamin D and how the sun is the best source for it, but one can always use a refresher course. And with the sun’s rays beaming far less frequently this time of year, it’s important to “make hay while the sun shines.”

When I say, “make hay,” of course I mean reaping the benefits of the sun’s rays as just being exposed to them increases vitamin D levels. And as I said, at this time of year, vitamin D is at a premium due to daylight saving time (the shortest day of the year is just two weeks away!).

The dearth of sun and low vitamin D levels has serious health consequences, perhaps the most well-known being improper bone development. It manifests itself as rickets in the most severe of cases. But new research says that low vitamin D levels play a role in the most serious health hazard of our time: heart disease.

Several reports in several scientific journals – like Circulation and the Journal of the American College of Cardiology – chronicle the links between vitamin D and heart complications. For instance, one heart study indicates that people who get less than 15 nanograms per milliliter of vitamin D are twice as likely to have a heart attack, stroke or other cardiovascular-related issue in the next five years compared to those with higher vitamin D levels. And in a review of recent heart studies, Circulation cites data indicating low vitamin D levels carry a 30 to 50 percent increased risk of death among individuals with pre-existing heart conditions.

There are lots of sources from which to get high amounts of vitamin D, including salmon, cod and eggs. But the most plentiful source is the sun. And when it you stop and think about it, its little wonder vitamin D levels are so low – what with the prevalence of sunscreen and astronomically high SPF levels that remove the skin’s ability to absorb vitamin D. But that’s a concern for the summertime.

Since it’s the wintertime, what can one do to increase sun exposure without getting hypothermia? Fortunately, it doesn’t take long to get a good shot of vitamin D from the sun. Researchers say that as little as 10 minutes of direct exposure provides a good dose of vitamin D. For those with a serious “D” drought, it may require increased exposure (particularly if one’s complexion is dark) and high vitamin D supplementation to boot.

The point is, the sun is our friend; it’s not something to be shunned. Like anything, overdoing it – or in this case, overexposure – is not a good thing. But this season is the most important season to make every effort in supplementing with vitamin D, eating foods fortified with vitamin D and – when possible – stepping out and soaking up the sun.

Your heart depends on it.