Vitamin D in winter: a guide for Atlantic Canada

Every November, the same question starts coming up in our supplement aisle: "Should I be taking vitamin D?" It's a fair question. From about November to March, the sun in Atlantic Canada sits too low for your skin to make much vitamin D, however bright the day looks. So for a good chunk of the year, food and supplements do the heavy lifting.

Below are the daily amounts, where you can get vitamin D from food, and how to choose a supplement if you need one.

Why winter is different here

Your skin makes vitamin D from UVB light, and how much it makes depends on the angle of the sun. Halifax sits at about 44.6°N, and the rest of Atlantic Canada is farther north. Through the winter, the sun never climbs high enough for much UVB to reach us, even on a clear, cold day. From late spring to early fall, uncovered skin can make vitamin D around midday. (Sunscreen still matters. Sunburns and tanning beds are not a vitamin D plan.)

Statistics Canada has found that Canadians' vitamin D levels tend to dip in winter, which won't surprise anyone who has commuted home in the dark in January.

Keep going outside anyway. A winter walk does plenty for you, even if vitamin D isn't one of them.

What vitamin D does

Vitamin D helps in the development and maintenance of bones and teeth, and helps your body absorb and use calcium and phosphorus. That's the job, and it's an important one.

How much do adults need?

Adults 19 to 70 need 600 IU (15 µg) of vitamin D a day, and adults over 70 need 800 IU (20 µg). These amounts cover everything you get from food and supplements together.

Age	Recommended daily intake
Adults 19–70	600 IU (15 µg)
Adults over 70	800 IU (20 µg)

The usual guidance is for adults over 50 to take a daily 400 IU vitamin D supplement on top of following Canada's Food Guide.

A couple of practical notes:

Add it all up. If you take a multivitamin, a calcium-and-D product and a separate vitamin D, the IU from each counts toward your total.

Who should pay closer attention

Some of us are more likely to run low over the winter:

Darker skin. More melanin means less vitamin D from the same sunlight.

Mostly indoors. Office work, school, night shifts, long-term care.

Older adults. Skin makes vitamin D less efficiently with age.

Absorption issues. Celiac disease, Crohn's disease, weight-loss surgery and some medications can affect how you absorb fat-soluble vitamins.

Babies. The usual guidance is a daily 400 IU vitamin D supplement for breastfed infants.

If you'd like to know where your levels sit, your doctor or naturopathic doctor can order a blood test.

Food first, where you can

Very few foods have much vitamin D naturally, which is why Canada fortifies some staples.

Fatty fish. Salmon, mackerel, trout and sardines. Living by the ocean helps here, and a tin of Wild Planet sardines on toast counts.

Wild PlanetWild sardines in water, 125 gA pantry tin for sardines on toast.Shop →

Eggs. The vitamin D is in the yolk.

Fortified milk and margarine. Fortification is required by law in Canada, and as of January 1, 2026 the amount roughly doubled. A 250 mL glass of cow's milk now has about 200 IU.

Fortified plant-based drinks. Soy, almond and oat drinks labelled as fortified. Check the Nutrition Facts table.

Cod liver oil. It's also high in vitamin A, so follow the label.

Fish once or twice a week and fortified milk or a plant-based drink most days goes a long way. Getting all the way there from food alone is harder in winter, which is where a supplement comes in.

Choosing a supplement

D3 or D2? Most products in Canada use vitamin D3 (cholecalciferol), and research suggests it raises blood levels more effectively than D2. If you're vegan, look for D3 made from lichen.

Drops or softgels? Drops make it easy to adjust a dose and are handy for families. Softgels are easy to take and travel well. Gummies suit people who'd rather not swallow anything, but check the sugar. There's no wrong answer; pick the one you'll actually take.

Check the strength. Common amounts are 400 IU, 1,000 IU and 2,500 IU per serving. Multiply by the number of servings you take to get your daily total.

Look for the NPN. An eight-digit NPN (Natural Product Number) on the label shows the product is licensed for sale in Canada.

D3 with K2. You'll see a lot of D3 and K2 combinations on our shelf. Some people and practitioners prefer them because both nutrients play a role in how the body uses calcium. If you take a blood thinner such as warfarin, talk to your healthcare provider before taking anything with vitamin K.

Take it with food. Vitamin D is fat-soluble, so taking it with a meal that has some fat in it, like eggs, yogurt or a handful of nuts, can help absorption. Breakfast or supper, whichever you'll remember.

What we carry

These are a few of the vitamin D products on our shelves, from CanPrev, Naka and Natural Factors, all licensed for sale in Canada. Ask us in store or give us a call if you'd like help comparing them.

You'll find more in our bone and teeth health collection, and our guide to the best form of magnesium compares the forms on the same shelf. For vitamin C, zinc and elderberry, see our winter immune shelf guide.

In store: Bedford (486 Starboard Drive, (902) 835-9319) and Dartmouth (590 Portland Street, (782) 358-2374), open seven days a week.

Same day in HRM: Order by 11 am with Luminate Express and it arrives that afternoon.

Anywhere in Canada: Orders over $80 ship free, from Nova Scotia to the rest of the country.

Our naturopathic doctors are next door to the Bedford store if you'd like to book an appointment.

Questions we hear a lot

Can I store up enough vitamin D over the summer?

Your body does store some, but it runs down through the fall and winter, and how long it lasts varies a lot from person to person. Most of us are better off planning for winter than counting on August.

When should I take vitamin D?

Whenever you'll remember, with a meal that has some fat in it. Follow any timing directions on the label.

Do I need a blood test first?

Most adults don't need one to take a typical daily amount. Your doctor or naturopathic doctor may suggest one if they'd like to check your levels.

What about vitamin D for kids?

Children have their own recommendations by age. Use a product made for kids and follow the label. Don't give children adult-strength products unless a healthcare provider has recommended it.

Should I take vitamin D all year, or just in winter?

Some people take a modest amount year-round and some adjust by season. Either way, follow the directions on your product's label.