Let’s start this off with a disclaimer: I am not a medical health professional. What I’m sharing with you today is information that has been carefully researched and referenced from leading authorities in North America, such as the USDA. But ultimately, your doctor knows where it’s at, and this article is not a substitution for his or her medical advice.
Do you live in the warm tropics where sunlight is reliable and constant? Or the more southerly areas of the United States, such as Los Angeles, Florida or Austin? If so, UV rays are strong all year long in your area. For the rest of us, whether we be from parts of the US, Canada, Europe or Australia, the issue of getting adequate sunshine during the winter months is very important, since vitamin D is created in our bodies from UV rays.
In this article, we’ll discuss vitamin D – what it is, why we need it and where to get it, how much we should be getting, and vegan issues surrounding this important nutrient. We’ll also talk about supplements on the market and where you can find them. So let’s hop on to it!
What is Vitamin D, and Why Should I Care?
Vitamin D is kind of a weirdo vitamin because in addition to being able to use it from food and supplements, our bodies can manufacture it from sunlight, making it akin to a hormone. It’s a big team player with calcium, and not getting enough vitamin D means that our bodies aren’t able to absorb as much calcium from food, which is bad news for our bones. Getting enough vitamin D is even suggested to help combat certain cancers, hypertension, depression and other health problems, and is an exciting area of research, though still in its early stages. 
On a hot summer day, a light-skinned person might only need to be in the sun for 5-10 minutes to get enough vitamin D, but wintertime in more northerly latitudes is a different story. When the UV rays from the sun are no longer strong enough to help us make this vitamin, we can turn to either fortified foods such as soy milk, margarine or orange juice, or take a supplement. This is crucial for many of us, since authorities suggest that about three quarters of Americans are vitamin D deficient. 
Who Needs Vitamin D, and How Much?
For folks at a latitude of around 42 degrees north, which is about the level of Boston, Toronto and Detroit, UV rays aren’t strong enough to stimulate vitamin D production during December and January. For those of us even higher on the world map at around 50 degrees north, like the majority of Europe including the UK, and pretty much all of Canada with the exception of southern Ontario and Quebec, the sun’s UV rays fade between November to February.  Even if you live in a warm location, if you don’t get outdoors regularly or thick clouds tend to dominate the sky, you might want to be sure you’re getting enough vitamin D.
According to Health Canada and the US Department of Agriculture, the RDI (recommended daily intake) for kids and most adults is set at 600 IU (15mcg) per day. For folks over the age of 70, that number increases to 800 IU (20mcg). However, though we can’t overdose on vitamin D when we get it from sunlight, it’s possible to get too much of a good thing from supplements, so the upper limit has been set at 4,000 ICU (100mcg).
In order to meet the daily RDI for vitamin D from eating fortified foods, you could:
-Drink a little over 2 cups of Silk soymilk (or other fortified drink)
-Use 5 teaspoons of vegan Becel margarine
-Eat several bowls of fortified breakfast cereal (not all are vegan)
-Eat some combination of the above
Otherwise, during the dark winter months in northern locales, it’s prudent to take a supplement. They come in all shapes and sizes, from tablets to multivitamins, but I prefer liquid drops since it’s so easy and hassle-free to ingest.
Vegan Issues with Vitamin D
There are two types of vitamin D – vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). Vitamin D3 is used widely in fortified foods but is not vegan, since it’s derived from lanolin (wool fat). D2, on the other hand, is vegan and typically made from UV-saturated fungi. There has been some debate about the effectiveness of vitamin D2 in comparison to D3, but recent and comprehensive studies suggest that they both work well and can successfully treat deficiency. 
Companies such as Source Of Life Garden and Vitashine have come up with a vegan version of D3, which is made from something called Lichen, a type of plant that is sort of like a cross between a fungi and algae. Since these products are fairly new, there aren’t any studies documenting their use (that I know of), but they have been rigorously tested and are proven to contain cholicalciferol (D3).
Where To Buy It
I live in a smallish Canadian city of roughly 200,000 people, and have had no trouble finding vitamin D2 supplements at my local health food store. If you can’t find it on the shelves, talk to the shop owner – in my experience, they’re typically enthusiastic about ordering in products for you.
Otherwise, you can turn to the great world wide web, where vitamin D2 supplements can be found everywhere from Amazon to Vegan Essentials (US-based) or Karmavore (Canada-based).
Vegans, vegetarians and omnivores alike need a reliable source of vitamin D, especially during the cold winter months. Whether the source be sunlight, supplements, fortified foods or an assortment of all three, it’s important to ensure your intake is adequate for the sake of your bones and overall health.
1. Vitamin D Deficiency, Michael F. Holick, M.D., Ph.D., N Engl J Med 2007 (pdf)
2. Vitamin D deficiency soars in the U.S., study says, Scientific American, March 23, 2009
3. Becoming Vegan, Brenda Davis, R.D. and Vesanto Melina, M.D., R.D., 2000
4. Vitamin D2 Is as Effective as Vitamin D3 in Maintaining Circulating Concentrations of 25-Hydroxyvitamin D, Michael F. Holick, Rachael M. Biancuzzo, et al, J Clin Endocrinol Metab., 2008 March