Unless you’re choking down a tablespoon of cod liver oil every day, then you’re not getting enough of the sunshine vitamin.

And if you’re like me and try your darnedest to stay out of the sun (by wearing sunscreen every freaking day, and sometimes Burka-like clothes) then it’s critical you consider taking vitamin D supplements, especially now. Our go-to derm Dr. Lisa Kellett recommends taking daily supplements of vitamin D during the winter months to offset the body’s natural winter slowdown of vitamin D production due to shorter sunlight hours.

The shorter days may be one reason why two-thirds of Canada’s population has vitamin D levels below the amounts research is associating with reduced risk of chronic diseases. Back in the day Vitamin D (which is actually a hormone) was only known as calcium’s wingman, but today research shows it is so much more. Among the diseases that vitamin D guards against are breast cancer, type 2 diabetes, heart disease and multiple sclerosis. It also plays a role in the skin’s growth process, and it has shown effectiveness in taming itchy, flaky skin.

The problem is, Vitamin D is created from being outside in the sun, as the ultraviolet rays of the sun allow our skin to form it. And we all  know that dermatologists equate sunbathing to devil worship.  Sun damage goes beyond aesthetics. Too much sun can not only make your skin look like a vintage leather purse, but studies have shown that UV radiation can negatively affect your skin’s immune function by temporarily mucking with the way your white blood cells work. And of course, we all know by now, that if you’ve had even mild sunburns in the past, you’re at a greater risk of developing melanoma, the deadliest type of skin cancer.

Another reason why Canadians fall short on their D needs may be because most supplements on the drugstore shelves don’t provide enough of the essential nutrient. Most drugstore brands contain only 400 to 800 IU per serving, yet according to the National Institutes of Health, 600 IU is the recommended daily allowance (RDA) for adults 18 years or older. Interestingly in Europe, it’s much much higher. The European Food Safety Authority recently raised the RDA to levels far beyond North American guidelines; for adults it’s 4,000 IU per day.

That’s why I like USANA’s vitamin D. Each tiny pill contains 2000 IU so you can get your full day’s quota (plus!) in just one shot.

I’ve been using this brand for year now and I truly believe it’s helped kept me sick-free this winter while everyone I know got hit by flu.

Now I wouldn’t endorse a product unless its supported by an expert I trust. If you’re familiar with USANA, than you probably know of its network marketing business model. Just like Avon and Arbonne, you need to buy it from a rep…swarmy, I know.

But when I found out that Dr Susan Kleiner, PhD, RD, one of my most trusted nutrition expert works with USANA as a science consultant and as a distributor, I felt more confident in supporting this brand. Here, I ask Kleiner about USANA and the rock star vitamin.

What made you decide to align yourself with USANA?

The products are world class for purity and potency. Few can match their total package along with the science behind the products. I have been very impressed.

What is the latest consensus on RDA of vitamin D?

The funny thing is there is no consensus. In 2010 the IOM published the DRIs for vitamin D based solely its relation to calcium and bone health. The committee decided that there wasn’t enough cause and effect evidence for any recommendations relative to vitamin D and any other function in the body. This fact is where the controversy lies. The argument is that vitamin D functions as a hormone, not a vitamin. And since we get minimal sun exposure and in the capacity of a hormone we need significantly more than the DRI. Bone metabolism is just one function. Vitamin D is involved as a hormone in many physiological processes such as immune function, digestion, reproduction, neuromuscular function, diseases including cancer, diabetes, CVD, periodontal disease, and others. Many other scientists and clinicians recommend higher doses based on the evidence at hand.

What makes USANA vitamin D superior from other brands?

USANA guarantees the most potent and bioavailable form of the vitamin, vitamin D3, the active form found in your blood. It is in a single tablet maximum dose of 2000 IU. The USANA supplement also contains 30 mcg of vitamin K, which assists vitamin D and calcium to maintain bone health. USANA has third party lab testing and guarantees that all the products are pure. Over 600 Olympic athletes worldwide use USANA products.

So vitamin D delivers a myriad of heath benefits, but does it play any role in promoting skin health?

Basically vitamin D is in charge of cellular health, new cell production, and cell death, all extremely pertinent to skin cells. Vitamin D is also helps control inflammation, and the skin has constant assaults leading to inflammatory responses. The response is good and initiates the healing process, but without vitamin D it progresses unchecked, leading to unsightly skin. So skin problems from psoriasis to acne and others that are related to acute or chronic inflammation, may respond to vitamin D. Certainly maintaining healthy levels is important to support immune function everywhere in the body.

To purchase a bottle of USANA’s vitamin D ($24 at USANA.com), I suggest buying it from Dr Susan Kleiner.