If you eat salmon a few times a week and drink fortified milk, you might assume your vitamin D levels are covered. But when you look at the actual numbers, the gap between what food provides and what your body needs is bigger than most people expect.
Let's break it down.
How Much Vitamin D Do You Actually Need?
Health Canada recommends 600 IU (15 mcg) per day for adults aged 1 to 70, and 800 IU (20 mcg) for adults over 70. However, organizations like Osteoporosis Canada suggest that many adults may benefit from 800 to 2,000 IU daily, particularly during fall and winter months when sunlight exposure drops significantly.
For Canadians specifically, this matters. From October through March, the sun sits too low in the sky for your skin to produce meaningful amounts of vitamin D, no matter how much time you spend outdoors.
So the question becomes: can food fill the gap on its own?
Vitamin D in Common Foods: The Real Numbers
Here's where it gets eye-opening. Very few foods naturally contain vitamin D in significant amounts, and the ones that do aren't foods most people eat every day.
| Food | Serving Size | Vitamin D (IU) |
|---|---|---|
| Sockeye salmon (cooked) | 75 g (2.5 oz) | 570 IU |
| Rainbow trout (cooked) | 75 g (2.5 oz) | 600 IU |
| Canned tuna (light, in water) | 75 g (2.5 oz) | 60 IU |
| Sardines (canned) | 75 g (2.5 oz) | 70 IU |
| Egg yolk | 1 large | 40 IU |
| Fortified cow's milk | 1 cup (250 mL) | 100-200 IU |
| Fortified plant-based milk | 1 cup (250 mL) | 80-120 IU |
| Fortified orange juice | 1 cup (250 mL) | 100 IU |
| Fortified margarine | 1 tsp (5 g) | 25-30 IU |
| Beef liver (cooked) | 75 g (2.5 oz) | 36 IU |
| Mushrooms (UV-exposed) | 1/2 cup | 150-375 IU |
Note: In Canada, cow's milk and margarine are required by law to be fortified with vitamin D. Fortification of plant-based beverages and yogurt is voluntary, so always check the label.
What a Typical Day of Eating Actually Provides
Let's say you have a glass of fortified milk with breakfast, an egg at lunch, and a serving of canned tuna at dinner. That's a better-than-average day for vitamin D from food:
- Fortified milk (1 cup): ~120 IU
- 1 egg yolk: ~40 IU
- Canned tuna (75 g): ~60 IU
- Total: ~220 IU
That's roughly a third of the minimum recommended intake for most adults, and well under half of what many health professionals suggest for Canadians.
Even on a great day where you eat a full serving of wild salmon, you'd get around 570 IU from that meal alone. That's solid, but most people aren't eating salmon every day.
According to national survey data, the average daily vitamin D intake from food and beverages in adults is only about 150 to 230 IU per day. That falls short of even the most conservative recommended intake.
Why Food Alone Usually Isn't Enough
There are a few reasons the "food-only" approach falls short for most people:
The list of natural food sources is very short. Outside of fatty fish and egg yolks, almost no whole foods contain meaningful vitamin D. You're largely relying on fortified products, and those typically provide modest amounts per serving.
Consistency is hard. Getting enough vitamin D from food requires eating specific foods every single day. Most people's diets vary, and that variation creates gaps.
Canada's geography works against you. For roughly six months of the year, we Canadians can't rely on sunlight to make up the difference. That puts extra pressure on dietary sources, and as the numbers show, food alone typically can't carry the full load.
Absorption varies. Vitamin D is fat-soluble, which means your body absorbs it best when eaten alongside dietary fat. If your meals are low in fat, or if you have a condition that affects fat absorption, you may get even less from food than the numbers suggest.
Does This Mean Food Doesn't Matter?
Not at all. Food absolutely contributes to your vitamin D levels, and choosing vitamin D-rich foods is a smart habit. Fatty fish, eggs, fortified milk, and fortified plant-based beverages all play a supporting role.
But "supporting role" is the key phrase. For most Canadians, food provides a foundation while a daily supplement fills the rest of the gap.
Osteoporosis Canada puts it directly: Canadians cannot get enough vitamin D through diet alone, and routine supplementation is recommended for all adults.
A Practical Approach
If you want to make the most of your vitamin D intake, a combined strategy tends to work best:
Eat vitamin D-rich foods regularly. Include fatty fish a couple of times per week, choose fortified dairy or plant-based milks, and don't skip the egg yolks.
Take a daily vitamin D supplement. For most Canadian adults, a supplement in the range of 1,000 IU is a common, well-tolerated daily dose. If you're unsure, talk to your healthcare provider about what's right for you.
Take vitamin D with food that contains fat. Whether from food or a supplement, vitamin D is absorbed much better when paired with fat. A handful of nuts, a drizzle of olive oil, or an avocado alongside your supplement can help. For more on this, read our guide on foods to eat with vitamin D for better absorption.
Be consistent. Vitamin D works best as a daily habit, not something you take on and off. The best time to take vitamin D is to just consistently take it. Pick a time that fits your routine and stick with it.
The Bottom Line
Food is an important part of any vitamin D routine, but for most people, especially those living in northern climates like us in Canada, it's not enough on its own. The gap between what food provides and what your body needs is real, and a quality supplement is the simplest way to close it.
If you're just getting started with vitamin D, our complete guide to vitamin D covers everything from how it works to how to choose the right supplement. And if you're already supplementing, learning about the best supplements to take alongside vitamin D can help you get even more out of your routine.
