Why spring is the perfect time to improve your mood

Despite the sometimes gray skies of April, many of us feel a familiar lift in spirits. That post-winter mood boost isn't just your imagination—there's fascinating biology at work, centered around a crucial nutrient that nearly half of Americans don't get enough of.

The Winter-Spring Mental Health Connection

If you've ever felt like a different person once spring arrives, you're not alone. What many experience as winter blues transforms into a natural mood elevation that mental health professionals have dubbed the "spring surge." During winter's short, dark days, approximately 10%-20% of Americans experience Seasonal Affective Disorder (SAD), characterized by depressed mood, low energy, and increased sleep, according to the Cleveland Clinic. But as spring progresses, those symptoms often naturally reverse.

Vivian Chung Easton, a mental health clinician at Blueprint, a company focused on building AI-powered tools for therapists, explains, "This seasonal transition isn't just about feeling happier because winter is over. There's complex neurochemistry at work." A primary contributor to this seasonal brain chemistry shift is vitamin D.

The Science Behind Vitamin D and Mental Health

Here's where things get interesting: Vitamin D has a dual identity. While we classify it as a nutrient, it actually functions as a hormone in the body. Unlike most nutrients that we can only get through diet, our skin synthesizes vitamin D when exposed to UVB rays from sunlight—earning it the nickname "the sunshine vitamin."

That unique creation process helps explain why so many of us are lacking it: According to research from the National Institutes of Health, approximately 42% of Americans are vitamin D deficient, with even higher rates in northern regions where winter sunlight is scarce and weak.

So why does this deficiency matter for mental health? The connection lies in how vitamin D functions within the brain. Vitamin D receptors exist throughout the central nervous system, including brain regions involved in mood regulation. When activated, these receptors influence the production and action of neurotransmitters like serotonin and dopamine—the very chemicals targeted by many antidepressant medications.

Spring and Vitamin D: A Natural Mood Booster

The brain's relationship with vitamin D goes deep—quite literally. Vitamin D receptors are abundant in the hypothalamus, limbic system, and prefrontal cortex—key regions related to our emotion, motivation, and cognitive function. When these receptors don't get enough vitamin D, our mental processing can suffer.

The evidence connecting vitamin D to mood is growing. The British Journal of Psychiatry published research revealing that people with depression are 14% more likely to have low vitamin D levels compared to nondepressed individuals. Even more compelling, studies published in the Journal of Clinical Endocrinology & Metabolism have found that vitamin D supplementation can improve depression symptoms by 30%-40% in people with deficiency.

This relationship helps explain the pattern many people report every spring: feeling mentally sharper, more energetic, and emotionally balanced after a few weeks of increased sunlight exposure. As our bodies rebuild vitamin D stores depleted during winter, our brains receive the support needed for optimal function.

Practical Ways to Boost Vitamin D's Mental Health Benefits

Spring offers the perfect opportunity to naturally increase your vitamin D levels while also engaging in activities that support mental well-being. According to the Cleveland Clinic, just 10-15 minutes of midday sun exposure can jumpstart the process of producing vitamin D for people with light skin types, and 25-40 minutes for folks with more melanated skin.

According to Vivian Chung Easton, here are evidence-based ways to capitalize on spring's vitamin D potential:

• Fitting in some outdoor exercise: Getting some physical activity into your day provides an additional boost to your mood through releasing endorphins—and when done outside, you get the added vitamin D benefit. If available, try taking a brisk walk instead of opting for driving, or getting outside during a lunchtime break.
• Adding sunshine to your morning routine: Incorporate getting some extra sunshine into your morning routine. Consider having your morning coffee outside, listening to the news while taking a walk around the block, or taking a mindful moment outdoors before starting your day. 
• Bring socializing outdoors: Combine the mood-boosting effects of social connection with sunlight exposure. For example, if you're meeting a friend for coffee, you can walk and talk, or maybe sit outside. Socializing on your phone also counts too. Try calling a loved one while taking a walk or sitting outside.  
• Being smart about supplements: While food provides minimal vitamin D (typically only 5%-10% of recommended intake according to the American Journal of Clinical Nutrition), taking vitamin supplements can help. Pay close attention to the labels of potential supplements: There can be a variety of dosages. Before you start any supplement regimen, it's essential to consult a healthcare provider, as vitamin D levels can be measured through a simple blood test to determine your specific needs.
• Take your hobbies outdoors: Consider whether some of your hobbies can be done outside, this can include anything from puzzles to reading to taking some photos. You can also create some new outdoor hobbies like gardening or biking, that will help you get more sun, as well as encourage screen-free time, so you can take a break and recharge.  

What can be particularly effective is combining approaches. Taking both supplements and getting some spring sunlight addresses both our biochemical needs—and leads to behavior changes like getting outdoors, moving more, connecting with others—which address multiple pathways for improving mental health.

Embracing the Spring Sun

As days lengthen and temperatures rise, spring presents a natural opportunity to restore your vitamin D levels and potentially improve mental well-being. While not a cure-all for serious mental health conditions, addressing a vitamin D deficiency is one evidence-based approach to supporting your brain health and regulating your mood.

The beauty of the spring surge is its accessibility. Unlike many wellness trends that require expensive products or complicated regimens, sensible sun exposure costs nothing and requires minimal time investment. Combined with other mood-supporting practices like regular exercise, stress management, and social connection, increasing vitamin D levels offers a scientifically proven approach to feeling better as the seasons change.

So the next time you find yourself drawn to that patch of sunlight streaming through your window or feel the urge to take a midday stroll, know that spring sunshine isn't just brightening your environment—it's also illuminating your mood from the inside out.