Vitamin D Explained: Deficiency Symptoms and How to Boost Your Levels

A few years ago when I was living in Winnipeg, winter felt endless. The sky stayed grey, and even stepping outside bundled in layers, I barely saw the sun. At the time, I was still breastfeeding my first son, juggling teaching yoga, and trying to keep myself well. What I didn’t realize was that my body was running on empty in one crucial way: vitamin D.

I only found out because I went to a naturopath to get some blood work done. I was shocked — my vitamin D levels were incredibly low. To make things even more layered, I later found out I was four weeks pregnant with my second baby. No wonder I felt like I was going crazy. Vitamin D deficiency was depleting me at a time when my body was already giving so much.

And I’m not alone. Long winters, busy lives, and indoor routines mean vitamin D deficiency is common. In fact, about 32% of Canadians and 42% of Americans have insufficient levels, according to national health surveys. That’s almost half of us walking around with low stores of a nutrient that impacts everything from bone strength to mood.

What is Vitamin D?

Vitamin D isn’t just a vitamin — it’s actually a hormone. When UVB rays from the sun hit our skin, our body makes vitamin D. But in northern climates (like Winnipeg), that process doesn’t happen for months at a time because the sun’s angle is too low.

There are two main dietary forms:

• Vitamin D2 (ergocalciferol): Found in some plants and fungi. It’s less effective in raising blood levels.

• Vitamin D3 (cholecalciferol): Found in animal-based foods like fish, eggs, and fortified dairy. It’s the form your body makes naturally from sunlight and is generally more effective.

Both forms are transformed in the liver into 25(OH)D — the storage form tested in bloodwork. From there, your kidneys turn it into the active form that your body uses.

How to Get Vitamin D

Sunlight: About 10–30 minutes of midday sun on arms and legs, a few times a week, can keep levels healthy in the summer months. But in Canada and much of the northern U.S., this isn’t possible from October to April.

Vitamin D Food Sources (per serving)

• Salmon (wild, cooked 100 g / ~3.5 oz): ~500–600 IU (12–15 mcg)

• Salmon (farmed, cooked 100 g): ~250–300 IU (6–8 mcg)

• Sardines (canned in oil, 2 fish ~50 g): ~180 IU (4.5 mcg)

• Mackerel (Atlantic, cooked 100 g): ~360 IU (9 mcg)

• Egg yolk (1 large): ~40 IU (1 mcg)

• Fortified cow’s milk (1 cup / 250 mL): ~100 IU (2.5 mcg)

• Fortified plant milks (soy, oat, almond; 1 cup): ~100 IU (2.5 mcg) — check label, amounts vary

• Fortified orange juice (1 cup): ~100 IU (2.5 mcg)

• Cod liver oil (1 tsp / 5 mL): ~450 IU (11 mcg)

• Mushrooms (UV-exposed, raw 100 g / ~1 cup sliced): ~400 IU (10 mcg)

  • Note: Regular mushrooms without UV exposure have negligible vitamin D.Even with a nutrient-rich diet, it’s hard to meet daily needs through food alone.

Even with a nutrient-rich diet, it’s hard to meet daily needs through food alone.

Supplements :

• Vitamin D3 is generally more effective than D2.

• Look for supplements without unnecessary fillers or marketing hype (you don’t need “special delivery systems” or fancy labels — just quality D3 with third-party testing).

• Pairing vitamin D with vitamin K2 and magnesium helps with absorption and directing calcium to the right places (your bones, not your arteries).

💡 Quick comparison:

• The RDA (Recommended Dietary Allowance) for most adults is 600–800 IU daily (15–20 mcg).

• A single serving of wild salmon or 1 tsp of cod liver oil can meet or exceed that need.

• For most people, diet alone isn’t enough year-round, which is why supplements are often recommended.

Signs & Symptoms of Vitamin D Deficiency

Vitamin D deficiency doesn’t always scream at you — it whispers. But those whispers can add up:

• Fatigue and low energy

• Brain fog or feeling “off” mentally

• Low mood, even depression (sometimes called “seasonal affective disorder” in the winter months)

• Frequent illness (weakened immunity)

• Bone or muscle aches

• Poor recovery from workouts

• In severe cases, bone loss and fractures

Looking back, many of these symptoms lined up with what I was experiencing in Winnipeg.

What to Watch Out For

The wellness market knows vitamin D is trending. But here are a few red flags when choosing supplements:

• Overhyped claims like “cures everything.”

• Tiny doses that won’t make a difference (most adults need 1000–2000 IU daily, though your provider may recommend more if you’re deficient).

• Mega doses without medical supervision (too much vitamin D can cause problems with calcium levels).

• Lack of transparency — no mention of third-party testing or sourcing.

How to Raise Your Levels Effectively

1. Get tested. A simple blood test can confirm your levels.

2. Supplement smart. Vitamin D3 with K2 and magnesium is a strong combo.

3. Soak up summer sun. Bank those reserves in the warmer months.

4. Eat whole foods. Aim for fatty fish twice a week, eggs, and fortified options.

5. Stay consistent. Vitamin D works best when taken regularly, not sporadically.

Closing Thoughts

That naturopath appointment in Winnipeg was a turning point for me. I realized my “winter blues” weren’t just in my head — my body was asking for help. With the right support, I was able to restore my levels, feel more like myself again, and carry on through pregnancy and breastfeeding in a much stronger place.

Vitamin D isn’t glamorous, but it’s foundational. It supports your bones, your immunity, your energy, and your mood. And especially if you live in a northern climate or spend a lot of time indoors, it’s worth paying attention to.

Think of it like fuel for your inner light — helping you shine brighter even in the darker months.

As we move our way into the colder and darker season here in the northern hemisphere, this is one to keep top of mind. Stock it in your holistic medicine cabinet right alongside your teas, tinctures, and cozy rituals. A little consistency now can carry you through the months ahead with more energy, resilience, and ease.

May your tea be hot, your blanket cozy, and your vitamin D levels steady 🌙☀️

Larissa- Founder of RoamWell

P.S. At RoamWell, I believe our personal wellness and the planet’s wellness are connected. That’s why I love what Earth Conscious Life is doing—sharing holistic, solution-focused stories that remind us when we care for our health, we also care for the Earth. 🌎☀️

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