Vitamin D and Emotional Support Animals

Dr. Rick Rieser, MD – April 7, 2025

How They Are Connected and What the Science Says

Mental health is influenced by many factors, including lifestyle choices, physical health, finances, and social connections. Two factors that can work together in a powerful way are Vitamin D and the support of an emotional support animal (ESA). Vitamin D and the company of a faithful ESA can both reduce anxiety, decrease depression, and improve mood while boosting an overall sense of well-being.

In this article, we explore recent scientific information on how Vitamin D levels and ESAs can affect emotional and mental well-being. We will review how they are connected and what roles they can play in supporting both emotional and physical health.

Vitamin D: The “Sunshine Vitamin” and Mood Regulator

While it’s usually called a vitamin, Vitamin D is actually a precursor to a hormone that is essential for overall health. It is produced when our skin is exposed to sunlight. Most people know about its crucial role in bone health, but many are unaware of its role in brain function and mood regulation.

Numerous Vitamin D receptors are spread throughout the human brain in multiple areas, including the prefrontal cortex and the hippocampus. The hippocampus is a region involved in memory and emotion. This suggests a direct connection between Vitamin D, mood, and individual behavior. Research has also shown that Vitamin D has anti-inflammatory and antioxidant properties, which may counteract biological factors that play a role in depression and anxiety.

Vitamin D and Mental Health

Over the years, research has found a connection between Vitamin D levels and mental health, particularly in relation to depression and anxiety. In 2013, a large meta-analysis in the British Journal of Psychiatry showed that many people with depression had significantly lower Vitamin D levels than their non-depressed counterparts. In this analysis, low Vitamin D levels were associated with about 1.3 times higher odds of depression and more than double the risk of developing depression in the future.

Additionally, other recent research has shown that Vitamin D deficiency is often associated with individuals suffering from anxiety and mood disorders, and that lower levels often correlate with more severe symptoms.

What the Studies Show

A national study of over 12,000 US adults showed that higher Vitamin D blood levels were linked to lower anxiety symptoms. Those with the highest Vitamin D levels had about a 20%–25% lower risk of anxiety compared to those with the lowest levels. These findings suggest that maintaining healthy Vitamin D levels is important for mental well-being.

Winter Blues and Vitamin D

Many people notice that their mood tends to dip during the winter months. This phenomenon is known as Seasonal Affective Disorder (SAD) or winter depression. It is often due to reduced sunlight exposure caused by colder temperatures and shorter days.

When individuals are exposed to less sunlight, their ability to produce Vitamin D is diminished, which has been linked to worsening mood and SAD. An official VA bulletin noted that during the darker and colder months, we can make less Vitamin D, which can lead to diminished mental health and depression.

This is one reason many doctors recommend getting outside on bright days when possible and, if needed, using light therapy. Spending more time outdoors, even when it’s cold, allows individuals to soak up mood-lifting natural light and helps the body produce more Vitamin D—offering a double boost for mental health.

Decades of research, including high-quality randomized controlled trials, have investigated whether boosting Vitamin D can improve mental health. The results show that adequate Vitamin D levels are associated with better mood, and supplementation can benefit certain people, especially those who are deficient.

Depression

In 2023, an umbrella meta-analysis (a review of multiple meta-analyses) confirmed that Vitamin D has a beneficial impact on depression. After gathering data from numerous trials, researchers found that Vitamin D supplementation significantly reduced depressive symptoms compared to placebo, with a moderate effect size.

Put simply, people who took Vitamin D often reported feeling less depressed than those who did not. Another recent analysis in 2024 focused on people with clinical depression and found a small but significant improvement in depressive symptoms with Vitamin D supplementation. In that study, the greatest benefit was seen in patients who reached blood Vitamin D levels above about 50 nmol/L, suggesting that correcting deficiency is key.

Anxiety and Negative Emotions

A comprehensive meta-analysis of depression and anxiety showed promising evidence for Vitamin D’s role in reducing negative emotional states. In this review of 25 clinical trials, Vitamin D supplementation significantly reduced negative emotions, especially in people with major depressive disorder and in individuals who were Vitamin D deficient.

Patients with Vitamin D serum levels at or below 50 nmol/L who supplemented Vitamin D for at least eight weeks showed notable improvements in mood and anxiety scores. Another trial reported that six months of Vitamin D supplementation led to reduced anxiety symptoms, even when depressive scores did not change as much. This suggests that Vitamin D may particularly help with anxiety through calming neurochemical effects. While research is ongoing, many studies indicate that optimizing Vitamin D levels can help people feel less anxious and more emotionally balanced.

Overall Sense of Well-Being

Beyond clinical diagnoses, Vitamin D levels may contribute to overall mental wellness. Many people report increased energy and a better outlook in the sunnier, warmer summer months when Vitamin D production is at its highest.

As mentioned, several studies have shown improvements in mood with supplementation, especially in those with low levels. Because Vitamin D plays a role in brain regions related to pleasure and reward, scientists are investigating its connection to conditions like fatigue, irritability, and overall quality of life. While more research is needed, maintaining sufficient Vitamin D levels is considered one important piece of the puzzle for supporting mood and well-being.

Reported Risks and Benefits Around Vitamin D

People with extremely low Vitamin D levels (less than 20 ng/mL, or 50 nmol/L) show higher rates of depression in many studies. In one cohort study, individuals with deficiency had more than double the risk of developing depression over time compared with those who had adequate levels. Low Vitamin D is often observed in patients with severe depression. It is not always clear whether low Vitamin D causes depression, or if depression leads to changes in activity and sunlight exposure that result in lower Vitamin D—but it is still important to check.

It is always a good idea to talk to your doctor about a blood test to see if your Vitamin D levels are adequate, especially if you are suffering from anxiety or depression.

Vitamin D and Seasonal Affective Disorder (SAD)

Depression associated with different seasons is a good example of how environment and Vitamin D intersect. In the winter, shorter daylight hours and staying indoors to avoid the cold mean that many people’s Vitamin D levels plummet. This form of depression often lifts with the arrival of spring.

Some physicians advise individuals to take Vitamin D supplements in the colder months to keep levels in a healthy range. Getting outside for a walk at midday is one simple action that can help increase Vitamin D. In some locations, light therapy lamps are prescribed as a treatment for SAD. While the primary purpose is to regulate circadian rhythms, they can also support Vitamin D levels. If you struggle with seasonal mood swings, it is wise to pay attention to your Vitamin D and daylight exposure.

Emotional Support Animals and Their Mental Health Benefits

For someone struggling with anxiety, depression, loneliness, or other emotional hardships, an emotional support animal (ESA) can provide a kind of comfort that even counseling and medication sometimes cannot. An ESA is an animal that offers emotional support simply by being present. Individuals who qualify for an ESA have a disability related to their mental or emotional health. ESAs are different from service animals—they do not perform specific tasks related to a disability.

The presence of an ESA is often healing and comforting by itself. Science is beginning to prove what most pet owners know: animals can have a powerful positive effect on mental health. Multiple studies have shown that spending time with animals can lower stress hormones and increase oxytocin, a bonding hormone that makes people feel calm and happier.

Benefits of an ESA

• Reducing stress and anxiety: Playing with or even just petting a sweet, friendly animal can quickly reduce feelings of anxiety and stress. Some studies have shown that having a positive interaction with a dog for only a few minutes can significantly reduce feelings of anxiety and worry. ESAs provide a soothing presence that can help panic or anxiety attacks subside more easily and quickly.
• Easing feelings of loneliness: One reason ESAs are so effective is companionship. An ESA is an ever-present friend, which can be life-changing for someone suffering from isolation and loneliness. Research has shown that pets can significantly alleviate loneliness. ESAs give their owners the feeling of being needed and less alone simply by being there.

Other Ways ESAs Help

• Providing unconditional love and support: Unlike people, animals do not judge or hold grudges. This nonjudgmental support is especially important for individuals suffering from depression or PTSD, who may have trust issues or feel stigmatized. Knowing that their ESA will love them no matter what can boost self-esteem and provide a sense of belonging.
• Creating structure and purpose: Caring for an ESA adds structure to a person’s day. Feeding, grooming, and walking a pet provide routine and stability. This can be especially helpful for people with depression who have difficulty getting out of bed or finding motivation. An ESA depends on its owner, which can motivate the owner to take better care of themselves as well.

PTSD Relief

One study of veterans with PTSD showed that having a dog significantly reduced feelings of loneliness, depression, and irritability while increasing feelings of peace. There are many reports of animals sensing when their person is in crisis and staying close to help them get through it. Many mental health professionals now recognize ESAs as an important complementary part of treatment for anxiety and depression.

Outdoor Exercise With Your ESA: A Natural Mood Booster

One especially beneficial connection between Vitamin D, exercise, and ESAs comes from taking your ESA outside for walks. It is like receiving three kinds of therapy at once. You receive the emotional comfort of being with your ESA while also getting the mood-enhancing benefits of physical activity and a dose of Vitamin D from sunlight.

It has been well established that regular exercise can be as effective as medication for mild depression and anxiety in many patients. Physical activity releases feel-good chemicals such as endorphins that improve mood and promote relaxation. Simply adding a daily walk can make a big difference in mental health.

Add to that the motivation that comes from a super-excited ESA who needs daily exercise and sunlight, and you have a recipe for meaningful improvement in mental health.

ESA Owners Tend to Get More Exercise

Many studies show that dog owners are far more likely to meet their daily exercise recommendations. In some research, over 60% of dog owners met the recommended 150 minutes of moderate exercise per week, largely because they walk their dogs. Consistent activity contributes to better mental health for ESA owners and better overall health for both the ESA and the owner.

Another excellent aspect of exercising outside with an ESA is the healing effect of nature itself, often called “green exercise.” Research has found that physical activity in natural environments has an amplified positive impact on mood compared with indoor exercise. A 2021 systematic review showed that nature-based interventions significantly reduce depression and anxiety. Activities like walking, gardening, or conservation work in green spaces—combined with fresh air, greenery, social interaction, and time with your ESA—can elevate your sense of well-being.

The Therapy of Walking

Many people find that being in a park or near water while walking their ESA brings a sense of calm and perspective that indoor workouts don’t provide. Walking with an ESA is not only exercise; it can also be considered a form of therapy. It encourages time outdoors, which has been shown to lower blood pressure and stress hormones and restore mental energy.

You are also more likely to get adequate sun exposure during daytime walks, which increases the body’s ability to synthesize Vitamin D from sunlight. Even just a few hours a week outdoors can help maintain healthy Vitamin D levels, which—as we’ve reviewed—can stabilize mood, reduce anxiety, and alleviate depression.

Social Interaction and Routine

Walking your ESA not only boosts your Vitamin D levels but also increases your opportunities to interact with other people. Many dog owners can tell you that conversations with neighbors and fellow pet owners often start with their animals. A sense of community and belonging is wonderful for mental health.

In addition, having a regular walking schedule—such as every morning and afternoon—adds routine, which can be grounding for people with anxiety and depression. It also provides a sense of accomplishment: “I did something helpful and healthy for myself and my ESA today. I walked half a mile, one mile, or more.” When you add together exercise, nature, sunlight, social connection, routine, and a faithful ESA by your side, you get a powerful, holistic approach to supporting mental health and well-being.

Key Takeaways: Integrating Vitamin D and ESA Care

Vitamin D and emotional support animals each offer unique benefits for mental health, but they do not have to be viewed separately. They can complement each other beautifully. Here are a few ways to integrate this knowledge into a healthier lifestyle or treatment plan:

Healthy ESA Practices

• Check Vitamin D levels: If you are experiencing signs of depression, fatigue, or anxiety—especially in winter—consider asking your healthcare provider to check your Vitamin D levels with a simple blood test. If your levels are low, your doctor may recommend supplementation. You can also add healthy Vitamin D sources to your diet and spend more time in the sun during safe peak hours as recommended by your provider.
• Go outside with your ESA: Getting outside with your ESA is a wonderful way to increase Vitamin D levels, get exercise, and enjoy social interaction, while boosting endorphins and creating a healthy daily routine.
• Combine “sun time” and “ESA time”: Incorporating time outdoors with your ESA gives you nature exposure, movement, connection, and sunlight—all of which can support emotional health.