Is Omega-3 the Same as Vitamin D? What Every Canadian Should Know

by Vorst Canada June 03, 2025

Although they serve different roles in the body, omega-3 and vitamin D are often confused. Learn how they differ, how they complement each other, and why both may be essential to your health.

Disclaimer: This information is not meant to replace expert medical advice, diagnosis, or treatment; rather, it is meant only for educational and informational purposes.

Table of Content

Are Vitamin D and Omega-3 the Same Thing?
Omega-3 Fatty Acids: What Are They?
What Is Vitamin D?
Important Distinctions Between Vitamin D and Omega-3
Are You Able to Take Them Together?
Omega-3 Fatty Acids' Health Benefits
Vitamin D's Health Benefits
Typical Canadian Shortfalls
Who Needs to Take Vitamin D or Omega-3 Supplements?
Conclusion
References and Resources

Are Vitamin D and Omega-3 the Same Thing?

Let’s get this straight: No, vitamin D and omega-3 are not interchangeable.

They are separate nutrients with different functions in your body, even though they frequently coexist in fish oil supplements or "brain-boosting" blends.

Omega-3 is a type of fat
Vitamin D is a fat-soluble vitamin—actually a hormone precursor

Although they operate in different systems and have distinct effects, both are vital to your overall health.

Omega-3 Fatty Acids: What Are They?

Omega-3 polyunsaturated fatty acids are essential fats your body cannot produce on its own. You must get them through food or supplements.

The three primary types are:

EPA (eicosapentaenoic acid): Found mainly in fatty fish
DHA (docosahexaenoic acid): Also in fish; essential for brain and eye health
ALA (alpha-linolenic acid): A plant-based omega-3 found in chia, flaxseeds, and walnuts

Omega-3s support heart health, brain development, and inflammation control.

What Is Vitamin D?

Vitamin D is a fat-soluble vitamin your body produces when exposed to sunlight—specifically UVB rays. It's also available through certain foods and supplements.

There are two primary forms:

Vitamin D2 (ergocalciferol): Plant-based
Vitamin D3 (cholecalciferol): Synthesized from sunlight or found in animal-based foods

Vitamin D is critical for:

Calcium and phosphorus absorption
Bone strength
Immune system support

Important Distinctions Between Vitamin D and Omega-3

Without a table, let’s break down the main differences:

Omega-3 fatty acids help regulate inflammation, support brain function, and protect the heart. They are key to the health of cell membranes and help control hormone-like signalling molecules.

Vitamin D, on the other hand, acts more like a hormone than a vitamin. It plays a major role in immune defence, mood regulation, and mineral absorption.

In short:

Omega-3 works in your cardiovascular and nervous systems
Vitamin D supports skeletal, hormonal, and immune balance

Are You Able to Take Them Together?

Yes—and you probably should.

Omega-3 and vitamin D are highly compatible and complement each other in a few important ways:

Both support immune function
Both help regulate mood
Since both are fat-soluble, omega-3 may improve vitamin D absorption

Many high-quality fish oil supplements now include vitamin D. Be sure to check the label for proper dosing, as the vitamin D content can vary.

Omega-3 Fatty Acids' Health Benefits

Here’s why omega-3 deserves a place in your diet or supplement routine:

Helps lower triglycerides and blood pressure for heart health
Enhances brain function and memory, particularly with DHA
Reduces inflammation, which may benefit joints and skin
May support mood regulation, especially in kids and older adults
Plays a key role in eye health and development

Vitamin D’s Health Benefits

Known as the "sunshine vitamin," vitamin D plays a powerful role in:

Calcium and phosphorus regulation for healthy teeth and bones
Boosting the immune system to fight infection
Supporting mood and emotional wellness—especially during dark winter months
Reducing the risk of some autoimmune conditions
Assisting in hormone synthesis and metabolic function

Typical Canadian Shortfalls

Vitamin D deficiency is common in Canada due to long winters and limited sun exposure. In fact, over one-third of Canadians have suboptimal levels during colder months.

Omega-3 deficiency is also widespread, particularly among those who don’t eat much fatty fish. Vegans and vegetarians may find it especially difficult to get enough EPA and DHA.

These deficiencies can lead to:

Fatigue
Brain fog
Mood swings
Weakened immunity
Inflammation and joint pain

Who Needs to Take Vitamin D or Omega-3 Supplements?

You may benefit from supplementation if you:

Live in Canada or another northern country
Spend most of your time indoors
Avoid fish or animal-based foods
Experience low energy or mood
Have joint, immune, or skin issues
Are pregnant, breastfeeding, or over 50

These nutrients are generally safe when taken as directed. However, speak with a healthcare professional if you have a chronic condition or are on medication.

Conclusion

Although vitamin D and omega-3 are often linked in wellness circles, they are not the same. But that’s not a bad thing.

Think of it this way:

Omega-3 is your body’s internal oil—supporting the brain, heart, and reducing inflammation
Vitamin D is the biological signal—guiding cells in mineral use and immune response

They aren’t interchangeable, but together, they are powerful allies in your long-term health—especially for Canadians who may be falling short on both.

References and Resources

Laing, B. B., Cavadino, A., Ellett, S., & Ferguson, L. (2020). Effects of an omega-3 and vitamin D supplement on fatty acids and vitamin D serum levels in Double-Blinded, randomized, controlled trials in healthy and Crohn’s disease populations. Nutrients, 12(4), 1139. https://doi.org/10.3390/nu12041139
Harvard Health. (2019, March 1). Fish oil and vitamin D supplements might offer some health benefits. https://www.health.harvard.edu/staying-healthy/fish-oil-and-vitamin-d-supplements-might-offer-some-health-benefits