Do You Actually Need That Multivitamin?
The surprising truth about supplements and what Canadians are actually missing.
Walk into any pharmacy and the supplement aisle can feel overwhelming. Multivitamins, magnesium, vitamin C, B-complex — the promise is simple: take this pill and fill whatever gaps your diet leaves behind. But a new Canadian study published in Applied Physiology, Nutrition, and Metabolism — the official journal of CSEP — suggests the reality is a lot more nuanced than that.
Here's what the research actually found, and what it means for you.
About 1 in 4 Canadians Takes a Multivitamin
Roughly 25% of Canadians regularly take a multivitamin/mineral supplement. The highest users? Children aged 1–8 and women over 51. And here's where it gets interesting: supplement use was significantly more common among higher-income, food-secure households — people who, statistically, are already eating better diets.
Researchers call this the "supplement use paradox": the people most likely to buy supplements are often the ones who need them the least. Meanwhile, those with lower incomes, food insecurity, or less nutritional awareness — who may genuinely benefit — are the least likely to use them.
The solution isn't necessarily a pill. It starts with understanding which nutrients you're actually missing, and where to find them on your plate.
The Nutrients Canadians Are Actually Low On And How to Fix It
The study examined three key nutrients of public health concern: Magnesium, Vitamin C, and Vitamin A. Here's the real picture — and the simplest food-first fixes for each.
Magnesium: The Biggest Gap Nobody's Talking About
Over half of Canadians who don't supplement are falling short on magnesium. Even among people who do take supplements, 52% still aren't hitting their target from diet alone. This is the most underappreciated deficiency in active Canadians.
Why does it matter? Magnesium is involved in over 300 processes in the body — muscle contraction, energy production, nerve signalling, and sleep quality. If you're training hard and recovering poorly, low magnesium is one of the first things worth addressing.
Food solutions — add these regularly:
Pumpkin seeds — one of the highest magnesium sources available, easy to add to smoothies, salads, or oatmeal (roughly 150mg per ¼ cup)
Black beans and lentils — a serving of cooked lentils provides around 70mg alongside protein and fibre
Dark leafy greens — spinach, Swiss chard, and kale are all strong sources; a cooked cup of spinach delivers roughly 160mg
Dark chocolate (70%+) — yes, really. A 30g square provides around 50mg and makes the "eat more magnesium" advice significantly easier to follow
Almonds and cashews — a small handful with lunch goes a long way
Whole grains — brown rice, quinoa, and oats all contribute meaningfully to daily intake
The Respyre habit: build one magnesium-rich food into each main meal rather than relying on a supplement to do all the work.
Vitamin C: Underestimated in Active People
Among non-supplement users over 14, roughly 25–54% of Canadians aren't hitting their Vitamin C targets. This matters beyond immune function — Vitamin C is essential for collagen synthesis, meaning it directly supports tendon, ligament, and joint health. If you're training consistently, your connective tissue needs it.
The good news: Vitamin C is one of the easiest deficiencies to fix with food, and it's almost impossible to overdo it from dietary sources alone.
Food solutions — these are surprisingly high in Vitamin C:
Red bell peppers — contain nearly double the Vitamin C of an orange, and they're one of the most versatile vegetables in the kitchen
Kiwi — two kiwis deliver more than your full daily requirement and make an excellent pre-training snack
Strawberries — a cup provides around 85mg, easy to add to a morning smoothie or overnight oats
Broccoli and Brussels sprouts — a serving of cooked broccoli has roughly 100mg; even slightly undercooked is better than skipping it entirely
Citrus — oranges, grapefruit, and clementines are reliable and portable
Guava — if you can find it, one guava contains over 200mg — among the highest of any fruit
The Respyre habit: add a raw or lightly cooked Vitamin C source to at least one meal per day. Heat degrades Vitamin C, so raw or quickly cooked wins.
Vitamin A: A Gap That Grows With Age
Vitamin A inadequacy is high among Canadians over 9, with rates climbing above 50% in some older adult groups who aren't supplementing. Vitamin A supports immune function, vision, and cellular repair — all processes that matter more, not less, as we age and stay active.
The important nuance here: there are two forms. Preformed Vitamin A (retinol, found in animal foods) can build up to excess if over-supplemented. Provitamin A (beta-carotene, found in plants) is converted by the body only as needed — making plant sources both safer and more flexible.
Food solutions — focus on colour:
Sweet potato — one medium sweet potato delivers well over your full daily Vitamin A requirement as beta-carotene
Carrots — half a cup of cooked carrots covers your daily target; raw works too but cooking slightly improves absorption
Butternut squash — excellent in soups, roasted, or blended; one cup provides over 100% of your daily needs
Leafy greens — spinach, kale, and romaine all contain meaningful beta-carotene alongside their other benefits
Eggs — one of the most practical sources of preformed Vitamin A, with a whole egg providing around 10% of daily needs
Liver — if it's in your rotation, even a small monthly serving is extraordinarily high in preformed Vitamin A (note: this is also where over-supplementing can be a concern — you don't need both regularly)
The Respyre habit: orange and dark green vegetables at dinner most nights covers this almost automatically.
When Supplements Do Make Sense
Food-first doesn't mean supplement-never. The research — and Canada's Food Guide — are clear that certain groups benefit from targeted supplementation:
Vitamin D for adults over 50 (Canada's Food Guide recommends 400 IU daily; most Canadians don't get enough sun exposure year-round to compensate)
Folic acid for women of childbearing age (this is one of the most evidence-supported recommendations in nutrition)
Magnesium if you're highly active and your diet is consistently low in the sources listed above
Vitamin B12 for those eating primarily plant-based diets, since it's found almost exclusively in animal products
If you're unsure where your personal gaps are, bloodwork through your doctor is far more useful than buying the most comprehensive bottle on the shelf.
The Supplement Paradox Re-framed
The study's most important finding isn't really about supplements at all. It's about the gap between who's spending money on nutritional products and who actually needs nutritional support. Higher-income, health-conscious Canadians are buying supplements on top of already-adequate diets — sometimes pushing certain nutrients into excess. Meanwhile, the people most likely to have genuine deficiencies are the least likely to address them.
The most democratizing nutrition strategy available is learning which whole foods close which gaps — and building meals around them consistently. That's something anyone can do regardless of what's on the pharmacy shelf.
The Respyre Bottom Line
Every recipe in our quarterly content drops is built with these gaps in mind — magnesium-rich seeds and legumes, Vitamin C from whole fruit and vegetables, beta-carotene from roasted root vegetables. The goal is never perfection. It's building a pattern where the nutrients you need show up on your plate most days without requiring a spreadsheet or a supplement stack.
Real food, consistently. That's the strategy that actually works.
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Source: Keshavarz P, Shakur AY, Vatanparast H. Bottle to body: how multivitamin/mineral supplements shape Canadian nutrient intake. Applied Physiology, Nutrition, and Metabolism. 2026;51:1–10. doi:10.1139/apnm-2025-0305
Published in the official journal of the Canadian Society for Exercise Physiology (CSEP)
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Colby Johnson is a CSEP-certified exercise physiologist and founder of Respyre Health & Performance Ltd. Respyre delivers customized corporate wellness programs for organizations across Atlantic Canada.
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