I’ve tried bundling up and going on morning circadian walks to get sun exposure (even if I couldn’t feel it). I’ve spent hours working in the glow of a sunlamp. But this year, I wanted to be proactive and target my seasonal mood issues from the inside out. Enter: mindbodygreen’s vitamin D3 potency+. A 2021 systematic review of 15 studies concluded that research supports a link between vitamin D levels and mood1, with lower levels of vitamin D increasing the prevalence of mental health challenges, and higher levels tied to fewer cases and, in some instances, improved mood. Another 2021 review homed in on the mechanism linking vitamin D and mood, concluding that vitamin D plays an essential role in the synthesis of serotonin2, which is often dubbed the “feel-good hormone” for its role in mood regulation. All this suggests that vitamin D and mood are inextricably linked. But what does that have to do with winter? Well, since vitamin D is synthesized from sun exposure (and found in low quantities in a small number of foods), I worry about my ability to get optimal amounts during the winter, if not year-round (more on that later). So, when I heard that mbg’s vitamin D3 potency+ delivers a research-backed dose of vitamin D3 with a trio of organic oils for optimal absorption, I figured it was worth a shot.* Of course, I try to support my mind in other ways too—like making time for movement, prioritizing sleep, eating balanced meals, and leaning on my community. But on days when life gets in the way of my mental self-care routine, I can rest easy knowing that I’ve done something to support my mood (and whole-body health) just by taking vitamin D3 potency+.* And I’ll continue taking vitamin D3 potency+, even as the seasons change, because I now know that vitamin D insufficiency is far from a seasonal problem. Many people assume they can meet their vitamin D needs just by spending some time outdoors, but if you live far from the equator (or wear sunscreen) simply getting outside may not do the trick: Altitude, season, clothing, pollution, skin tone, age, and time of day also have to be considered. As Michael Holick, M.D., Ph.D., professor of medicine, physiology, and biophysics at Boston University Medical Center and author of foundational research on vitamin D synthesis5, previously told mindbodygreen, “Unless you’re going to be a lifeguard or a hunter-gatherer, you’re not going to make very much vitamin D.” And while eating plenty of foods containing vitamin D is a great start, food alone isn’t a practical strategy for most people. A vegetarian like me would have to consume about 10 glasses of fortified milk6 (whether dairy or plant milk)or 20 whole eggs7 just to reach 1,000 IU of vitamin D3 (the body’s preferred form). And that amount won’t even move the needle if I want to achieve vitamin D sufficiency. Plus, many experts agree that to reach truly optimal blood serum concentrations of vitamin D (i.e., 50 ng/ml or more), one would have to consume closer to 5,000 IU of vitamin D daily or sometimes more depending on body composition. That nets out to over 100 eggs8 or 50 glasses of milk! (Or, a single gelcap of mindbodygreen’s vitamin D3 potency+.) It may even help with dry skin, as one clinical trial from Nutrients found a correlation between low blood serum levels of vitamin D and lower levels of skin moisture10. So while I love the mood-supporting benefits of vitamin D, I see taking a daily supplement as a strategy for supporting my overall health.* With 5,000 IU of high-quality algal organic vitamin D3, mindbodygreen’s vitamin D3 potency+ gives me peace of mind that I’m nurturing healthy vitamin D levels in the wintertime, and always.