Vitamin D; The “Sunshine Vitamin” and It’s Link to Mental Health

Trying to sort through the onslaught of online nutrition advice and how it relates to our mental health can be overwhelming. Dietitian’s cut through the sea of voices to offer evidence-based nutrition facts and sound advice from a place of science and genuine care for your well-being and health.

In general, we encourage our clients to try and eat a whole food diet that nourishes their body, mind and soul. We believe that nutrients should come from food first! Supplements are used only when individuals are struggling to eat whole foods and are managing a diagnosis of some sort. At times of diagnosis certain nutrients may be poorly absorbed or utilized by our body. Thus, supplementation is necessary to assist recovery.

In regards to our mental health, there are certainly a handful of nutrients that we need to bring to your attention. Evidence has shown that key nutrients support our mental health and overall cognitive functioning. These nutrients are the “five well-being warriors”, and include Vitamin D, Omega-3, Zinc, B-Vitamins, and Magnesium.

Over the coming weeks, as we enter into the darker months of winter and during these stressful times, Healthy Essentials Clinic will focus on these warriors.  Starting with the benefits of Vitamin D. Each blog post will delve into the evidence around each of these nutrients and their role in mental health.

The Basics

Vitamin D, the “sunshine vitamin”, is an essential fat-soluble vitamin that we primarily absorb from the suns UV rays. It is also absorbed in smaller amounts from certain foods in our diet and Vitamin D specific supplements. The more well-known functions of vitamin D include working alongside calcium to maintain healthy bones and teeth. As well as ensuring our muscles and immune system are function properly1. A less well-known function of vitamin D is its role in our mental health and cognitive functioning.
Another unique trait of vitamin D is that it must be activated2 in order to function within the human body. This is done via the kidneys, liver, and the brain3.

The Link to Mental Health

A recent review4 of all relevant studies researching the link between vitamin D and mental health found that low vitamin D concentrations are associated with depression. In other words, those individuals living with depression were more likely to have low vitamin D levels when compared to their counterparts without depression. This link between depression and low vitamin D levels has been modelled through many recent studies, as well as vitamin D’s imperative role in cognitive functioning5, and reduced stress responses6.

So, what exactly is the relationship between vitamin D and mental health? While more research is certainly warranted, we do have some research which sheds light on the potential relationship between vitamin D and our mental health.

There are specific areas in our brain that researchers know are associated with depression, and new research has found links between these areas of the brain and the activation of vitamin D4. One study found evidence that the activated form of vitamin D in our brains may in fact act as a growth factor, encouraging normal development and functioning of brain neurons3. Another study6 found a link between vitamin D and its role in reducing the production of corticosteroids (cortisol) in the hippocampal area of the brain.  Meaning that less of the “stress hormone” is produced and then circulated through the body. Elevated corticosteroid levels are associated with multiple cognitive disturbances, including major depression. 

Where Can We Get It, and How Much Do We Need?

We now know that vitamin D is important for just about every function and system in our body. So, where do we get it and how much do we need?

Since vitamin D is primarily absorbed from sunshine, deficiency is much less likely for those living closer to the equator. However, for those living north of the equator, the sun goes into some serious hiding during winter months. So, we have to make up for that loss by optimizing our diets with vitamin D rich foods and/or supplements.
Below is a table of the current recommended daily intakes of vitamin D in Canadafor different age groups7. The recommended dietary allowance refers to the minimum vitamin D needed to avoid deficiency. The upper tolerable limit refers to the maximum limit one should not surpass in order to avoid toxicity (unless recommended by a physician).


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Some of the most vitamin D rich foods include seafood, mushrooms, dairy products/fortified non-dairy products, and eggs. The chart below can be a helpful guide to understanding how much vitamin D can be found in these items2:


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As you can see from this chart, enriching each day to ensure we are consuming enough vitamin D from our diet may become tricky. Particularly if we are not kicking back the cod liver oil, or consuming copious amounts of fish and UV exposed mushrooms every day. So, that is where daily supplementation can play a role.

Most vitamin D supplements are fairly affordable, and available in liquid forms where one drop is equivalent to 1000 IU, making it an easy step to add to our daily routines.

On the average day, aiming to get above your age brackets recommended RDA (600 IU for most adults) and less than the upper tolerable limit (4000 IU) is a safe and non-invasive way to help optimize your mental health.

The Bottom Line

While more evidence is needed, there is ample evidence to suggest that vitamin D does play a crucial role in our health! Specifically, our bones, muscles, immune system and our mental health and cognitive functioning. 

Finding a way to get enough vitamin D into your day is most definitely one way we recommend optimizing overall health and mental well-being through nutrition.


1 Dietitians of Canada. (2020). What you need to know about vitamin D. Unlock Food. Received from,If%20you%20do%20not%20drink%20milk%20or%20fortified%20soy%20beverage,foods%20that%20contain%20vitamin%20D.

2National Institutes of Health. (2020). Vitamin D: fact sheets for professionals. Received from:

3Eyles, D. W., Smith, S., Kinobe, R., Hewison, M., & McGrath, J. J. (2005). Distribution of the vitamin D receptor and 1α-hydroxylase in human brain. Journal of Chemical Neuroanatomy, 29(1), 21-30.

4Anglin, R., Samaan, Z., Walter, S., & McDonald, S. (2013). Vitamin D deficiency and depression in adults: Systematic review and meta-analysis. British Journal of Psychiatry, 202(2), 100-107. doi:10.1192/bjp.bp.111.106666

5Przybelski, R. J., & Binkley, N. C. (2007). Is vitamin D important for preserving cognition? A positive correlation of serum 25-hydroxyvitamin D concentration with cognitive function. Archives of Biochemistry and Biophysics460(2), 202–205.

6Obradovic, D., Gronemeyer, H., Lutz, B. and Rein, T. (2006), Cross‐talk of vitamin D and glucocorticoids in hippocampal cells. Journal of Neurochemistry, 96: 500-509.
7Government of Canada. (2020). Vitamin D and calcium: updated dietary reference intakes. Received from: