Vitamin D is often called the “sunshine vitamin”—and for good reason. It plays a vital role in everything from bone strength and immune function to mood regulation and chronic disease prevention. Yet despite its importance, vitamin D deficiency is incredibly common, particularly in Canada and other northern climates where sunlight is limited for much of the year.
At Intrepid Health, we see vitamin D deficiency more often than people expect—sometimes with subtle symptoms that go unnoticed for years. In this blog, we’ll explain what vitamin D does, why it’s so essential, how to know if you’re low, and what you can do to get your levels back on track.
What Is Vitamin D and Why Do We Need It?
Vitamin D is a fat-soluble vitamin that functions more like a hormone in the body. It helps regulate the absorption of calcium and phosphorus, making it essential for strong bones and teeth. But its role doesn’t stop there—vitamin D also supports:
- Immune system strength, helping your body fight off viruses and bacteria
- Muscle function and coordination
- Mood and brain health, with links to depression and seasonal affective disorder
- Inflammation regulation, reducing the risk of autoimmune diseases
- Chronic disease prevention, including some cancers, type 2 diabetes, and heart disease
Because so many systems rely on it, a deficiency can lead to widespread and sometimes vague health concerns.
How Do We Get Vitamin D?
Unlike most vitamins, vitamin D is primarily produced in the skin when it’s exposed to ultraviolet B (UVB) rays from sunlight. It can also be obtained in smaller amounts from food and supplements.
Natural Sources of Vitamin D:
- Sun exposure (10–30 minutes of midday sun on face, arms, or legs, depending on skin tone and season)
- Fatty fish (salmon, mackerel, sardines)
- Egg yolks
- Fortified dairy products, orange juice, and cereals
- Cod liver oil
Unfortunately, in Canada, sunlight from late fall to early spring is often too weak for our skin to make adequate vitamin D—especially for those who spend most of their time indoors, wear sunscreen year-round, or cover their skin for cultural reasons.
Also Read: Pneumonia: What You Need to Know to Protect Your Health
Who Is Most at Risk for Vitamin D Deficiency?
Certain people are more likely to develop a deficiency, including:
- People with darker skin tones, who naturally produce less vitamin D from sunlight
- Older adults, whose skin is less efficient at synthesizing vitamin D
- People who live in northern latitudes, like most of Canada
- Individuals who work or spend most of their time indoors
- Breastfed infants, particularly if the mother is also vitamin D deficient
- People with digestive conditions, like Crohn’s or celiac disease, which impair absorption
- Those who wear sunscreen consistently, which blocks UVB rays needed for vitamin D production
- Individuals with obesity, as vitamin D is stored in fat cells and may be less bioavailable
Signs and Symptoms of Vitamin D Deficiency
Vitamin D deficiency can be silent for a long time, or it may cause non-specific symptoms that are easy to overlook or misattribute. These can include:
- Fatigue or low energy
- Muscle weakness or cramps
- Bone or joint pain, especially in the lower back or legs
- Mood changes, including irritability or depression
- Frequent infections or slower healing
- Hair thinning or loss
- Difficulty concentrating or “brain fog”
In more severe cases, vitamin D deficiency can lead to osteomalacia in adults (softening of the bones) or rickets in children, both of which can cause bone deformities and increased fracture risk.
Diagnosing Vitamin D Deficiency
At Intrepid Health, if we suspect a vitamin D deficiency based on your symptoms or risk factors, we’ll order a simple blood test called 25-hydroxyvitamin D. This test measures the active form of vitamin D circulating in your body.
Here’s how results are typically categorized:
- < 30 nmol/L – Deficiency
- 30–75 nmol/L – Insufficient
- 75–125 nmol/L – Optimal range
- > 125 nmol/L – May be too high, especially if from supplements
Treatment: How to Rebuild Your Vitamin D Levels
The good news? Vitamin D deficiency is treatable—and often preventable with the right strategies.
1. Supplements
Most people with low levels benefit from vitamin D3 supplements. Your doctor will recommend a dosage based on your current levels, typically ranging from:
- 800–2,000 IU per day for general maintenance
- Up to 4,000 IU per day under medical supervision for deficient individuals
- High-dose therapy (e.g., 50,000 IU weekly) for short-term correction in more severe cases
Supplements are usually taken with food, especially one that contains fat, to improve absorption.
2. Safe Sun Exposure
Spending just 10–15 minutes outdoors (without sunscreen) a few times a week during spring and summer can help maintain healthy levels—but it’s not enough during Canadian winters.
3. Dietary Boost
Incorporate more vitamin D-rich foods into your meals. While not usually enough to fully correct a deficiency, it’s a helpful piece of the puzzle.
Preventing Future Deficiency
Once your vitamin D levels are back to normal, you’ll want to maintain them. Here’s how:
- Get tested regularly, especially in fall or winter
- Continue a maintenance dose, even after symptoms improve
- Aim for moderate sun exposure when possible
- Stay active, as muscle use may help vitamin D circulate more efficiently
- Ask your doctor about combination supplements, like calcium with vitamin D, for bone health
When to Talk to Your Doctor
If you’re experiencing fatigue, low mood, muscle aches, or frequent colds—and especially if you fall into a high-risk category—it’s worth checking your vitamin D levels. You don’t have to wait until you’re sick to take action.
At Intrepid Health, we offer comprehensive blood testing, personalized treatment plans, and lifestyle guidance to help you feel your best through every season.
📩 Book an appointment at appointments@intrepidhealthgroup.com
📅 Or schedule directly at https://intrepid.cortico.ca
Don’t stay in the dark about your health. Let’s work together to make sure your vitamin D levels—and your well-being—stay strong all year long
