When you think of vitamin D what’s the first thing that comes to mind? Chances are that it’s not mental health. Researchers aren’t exactly sure how vitamin D is connected to depression but more and more studies show an association between low vitamin D levels and mental health problems…

As a nurse practitioner in the ER, I’ve treated many COVID patients over the last 18 months. After the first few months of the pandemic, a clear pattern began to emerge. People with low vitamin D levels were more likely to end up with severe COVID.  Study after study like this one published in Frontiers in Public Health from March of this year conclude that having sufficient Vitamin D levels circulating in the blood is associated with a significantly decreased risk of COVID-19 infection.

If only government health officials encouraged the masses to get a 25-OH test or calcidiol 25-hydroxycholecalciferol test (that’s the fancy way of saying a vitamin D test). Because getting a blood test is the only way for sure to know if you have sufficient levels. Even if you live in sunny Florida and spend plenty of time outside, you may still have low levels. So wouldn’t it make sense that making sure everybody had adequate vitamin D levels was a top national health priority? And if you found out that your levels were low, you could buy a vitamin D3 supplement to boost your serum levels. 

Sorry to turn this intro into a rant. It’s been a frustrating, challenging year as a frontline healthcare worker. I still love helping people recover. That part of the job is so rewarding. But public health policy can make you want to tear your hair out and yell. 

The Unsung Role of Vitamin D: Mental Health Support

Speaking of anger management, mental health and vitamin D, there’s another story brewing below the surface. I’d like to bring more attention to the connection between vitamin D and depression/mental health. 

For years, many people have known that vitamin D is important for bone health. In more recent years, there have been studies that show that the antioxidant, fat-soluble nutrient also supports heart health. And of course, over the last 18 months, the connection between vitamin D and immune function has taken the spotlight. 

Why Vitamin D Matters For Mental Health

But not enough attention is given to the role vitamin D plays in regulating mood. The publicity of this connection must become more widespread. That’s because most people  in the U.S. have insufficient levels of vitamin D. 

There’s some debate as to whether low levels of vitamin D cause depression or if it’s just a correlation. Regardless, depression itself is an epidemic. According to Issues in Mental Health Nursing, it’s the leading cause of disability worldwide, affecting over 120 million people. Approximately 10 percent of all adults in the US suffer from a depressive illness each year, according to Hopkins Medicine. Depression is also the leading cause of disability for Americans between the ages of 15 and 44.

One more sobering statistic to consider: one in four American adults suffers from a diagnosed mental health disorder any given year. 

Low Vitamin D Levels: An Epidemic

Now that you see how pervasive mental health problems are, let’s take a look at how common vitamin D deficiency or insufficiency is. 

This research estimates that over one billion (yes, with a “B”) people have either vitamin D insufficiency or deficiency. In light of this epidemic of low vitamin D levels, the first thing I want you to do after you read this article is to get some blood work done so you know what your baseline levels are. 

As a functional medicine practitioner and health coach, I can order a full panel of lab tests for you that will not only reveal your vitamin D levels but tons of other health markers such as a comprehensive analysis of 28 genes that will tell you everything you need to know about what the best foods and exercise are best for you and so much more…

Actually, take a break from this article now and schedule a complementary consultation with me to take your first step towards living your best life. 

Now then, where was I? 

Oh yeah, let’s take a look at what your vitamin D levels should be…

Vitamin D: What’s The Best Levels and Dosage?

Mainstream health experts and institutions such as the Mayo Clinic recommended the daily amount of vitamin D you should get either through the diet (which is hard to do, more on this in a bit) is 600 IU (international units) for people ages 1 to 70 years, and 800 IU for people over 70 years.

But most functional health experts like yours truly believe that’s far too low. Considering that most people on this planet are deficient in vitamin D, you probably need way more. In fact, some natural health experts suggest taking 4,000 IUs or 5,000 IUs or even upwards of 10,000 IUs per day. Is that a safe amount to take? Well, according to this study, the Endocrine Society Practice Guidelines recommend that up to 10,000 IUs daily was safe for adults. 

If you want to know the exact amount of vitamin D you should take for mental health as well as immune support, bone health, heart health and every other awesome thing vitamin D does for your body, the comprehensive lab reports I’ll order for you will reveal exactly the best dosage for your unique biochemistry.

Having levels of vitamin D lower than 30 ng/mL is considered insufficient. In my opinion, your vitamin D levels should actually be 40 or higher. And if your levels are less than 20, well then, Houston, we’ve got a problem; you’re technically vitamin D deficient. 

Most of my functional medicine and health coaching clients are women. And when it comes to low vitamin D levels, studies suggest women are more susceptible to having both vitamin D levels and mood disorders. 

Why Does Low Vitamin D Cause Depression And Mental Health Issues? 

Researchers aren’t exactly sure what the connection is. The theory goes that the hypothalamus gland, located on the underbelly of the brain, contains vitamin D receptors. Because the hypothalamus produces hormones that control mood, it’s possible that having low vitamin D levels could result in not having enough feel-good chemicals like serotonin. 

Can You Get Enough Vitamin D From Food Or Sunshine?

When’s the last time you ate Atlantic herring? Never? Me neither. Too bad because that’s the best dietary source of vitamin D. Next highest is canned salmon, which provides about 600 IUs. Remember, if you have low vitamin D levels, you really should shoot for a much higher daily intake than what the federal guidelines recommend. Unless you’re a native person living in the arctic, eating plenty of vitamin D-rich foods like arctic chars (fish), seal liver, fish eggs, walrus and whale blubber, the bottom line is that most everybody is not getting enough vitamin D from food and should be taking a supplement. 

As for sunshine, in a perfect world, we’d all be able to spend ample time outdoors sunbathing with plenty of skin exposed because that’s the most effective way for our body to make vitamin D. But life ain’t perfect. 


If you want to support your mental health, make sure you optimize your vitamin D levels. Get a blood test and work with a functional medicine/health coach to start living your best life. 

Until next time, 

Jenna Witt, NP