Say it with us: not all nutrient forms are created equal. There are certain nutrients that might go by the same name and behave very similarly, but still have some key differences that can actually impact the way our bodies are able to use them. This often comes down to the way nutrients are sourced or synthesized.

Vitamin D is no exception. You might already know that Vitamin D is a fat-soluble vitamin that plays a part in a variety of functions in the body, including calcium absorption, bone health support, and immune function (1). Basically, our bodies need Vitamin D to support foundational health—but maintaining ideal Vitamin D levels can be a challenge.*

While we use Vitamin D as an umbrella term, there are actually two major types of Vitamin D that our bodies use: Vitamin D2 (also known as ergocalciferol), and Vitamin D3 (aka cholecalciferol). And knowing the differences between these different forms can shed some light on how to supplement with Vitamin D.(2)

Vitamin D2 vs. Vitamin D3

Vitamin D2 is found naturally in some plant sources, like mushrooms, while Vitamin D3 is found in animal-sourced foods. Vitamin D3 is also the form of Vitamin D the skin naturally makes when exposed to sunlight. Both sound like solid bets, right? Well, there’s a catch. (1)

While the body can metabolize both Vitamin D2 and Vitamin D3, it’s shown that higher doses of Vitamin D2 aren’t quite as potent as Vitamin D3. This, coupled with the fact that Vitamin D3 is the form the body produces, is why many experts (including those on our science team) recommend supplementing with D3.* (3)

Getting Enough Vitamin D3

Unfortunately, sunlight just isn’t a reliable resource for Vitamin D3—there are too many factors that get in the way of consistent exposure, ranging from climate to SPF usage (a good thing!) to skin tone. That’s why many Americans are not getting enough Vitamin D or D3 from diet and sunlight alone.

It’s also why we opt for Vitamin D3 in our vitamins—we want to make sure we’re meeting our daily needs. Essential for Women 18+ was even clinically shown to increase Vitamin D levels over 12 weeks, as compared to no change in a placebo group.*

References:

1. National Institutes of Health Office of Dietary Supplements. Vitamin D Fact Sheet for Health Professionals. Retrieved from National Institutes of Health

2. Dietary Reference Intakes for Calcium and Vitamin D. (2011). doi: 10.17226/13050

3. Itkonen, S. T., Skaffari, E., Saaristo, P., Saarnio, E. M., Erkkola, M., Jakobsen, J., … Lamberg-Allardt, C. (2016). Effects of vitamin D2-fortified breadv. supplementation with vitamin D2 or D3 on serum 25-hydroxyvitamin D metabolites: an 8-week randomised-controlled trial in young adult Finnish women. British Journal of Nutrition, 115(7), 1232–1239. doi: 10.1017/s0007114516000192