Do Canadians Have Low Vitamin D Levels?

January 3, 2026 •

4 min read

According to Statistics Canada, about two-thirds of Canadians have sufficient vitamin D levels, but approximately 32% fall below the threshold for bone health. This raises the question: do Canadians have low vitamin D and what factors, including limited sun exposure and diet, contribute to these insufficient levels?

Quick Summary

An examination of Canadian vitamin D levels reveals that many individuals, particularly in winter and specific age groups, have insufficient or deficient levels. Key factors include Canada's high latitude, diet, supplement use, and other demographic characteristics.

Key Points

High Latitude is a Major Factor: Canada's high northern latitude means insufficient sunlight for vitamin D synthesis occurs between October and March, making dietary intake and supplementation critical.
Seasonal Deficiency is Common: Statistics Canada reports that the percentage of Canadians with insufficient vitamin D levels (<50 nmol/L) is significantly higher in winter (40%) compared to summer (25%).
Young Adults and Seniors are Most Vulnerable: Individuals aged 20-39 have the lowest rates of sufficient vitamin D, while older adults' production declines with age, although supplement use helps many seniors.
Diet and Fortification Play a Role: Common foods like milk and margarine are fortified, but most Canadians do not get sufficient vitamin D from diet alone, highlighting the need for supplements.
Supplements Show Significant Impact: Canadians who take vitamin D supplements are far more likely to have sufficient blood levels than non-users.
Low Levels Affect Bone and Muscle Health: Chronic low vitamin D can lead to bone pain, muscle weakness, and increases the risk of bone fractures and conditions like osteoporosis.
At-Risk Groups Need Year-Round Action: People with darker skin pigmentation, those with limited sun exposure, and individuals with obesity may need year-round supplementation.

Canada's Unique Challenge with Vitamin D

Canada's geographic location at a high latitude significantly impacts its population's ability to naturally produce vitamin D from sunlight. Between October and March, the sun's angle is too low for ultraviolet B (UVB) rays to stimulate adequate vitamin D synthesis in the skin. As a result, reliance shifts to dietary sources and supplements during these long winter months. This seasonal variation is starkly evident in national health data. The Canadian Health Measures Survey (CHMS) has shown that the percentage of Canadians with vitamin D levels below the recommended cutoff more than doubles in winter compared to summer.

Which Canadian Demographics Are Most at Risk?

While low vitamin D is a national concern, some demographic groups are more susceptible than others.

Young Adults (20-39): Data consistently shows that this age group has the lowest rates of sufficient vitamin D compared to younger children and older adults. In a 2016-2019 CHMS study, 13% of young adults had deficient levels (<30 nmol/L), the highest of any adult age group.
Seniors: While supplement use is higher among seniors and helps maintain their levels, their skin's efficiency at synthesizing vitamin D decreases with age.
Individuals with Darker Skin: Higher melanin content in darker skin acts as a natural sunscreen, reducing the skin's ability to produce vitamin D from sunlight. This places individuals of African, African-Caribbean, and South Asian backgrounds at higher risk, a factor exacerbated by the low sun exposure during Canadian winters.
Those with Limited Sun Exposure: Individuals who are housebound, live in long-term care facilities, or whose clothing covers most of their skin are at increased risk year-round.
People with Obesity: Individuals with a higher body mass index (BMI) have lower serum vitamin D levels, as fat cells can sequester the vitamin, making it less available for the body's use.

The Importance of Supplementation and Diet

Because of limited sun exposure, especially outside of summer, diet and supplementation become critical for maintaining healthy vitamin D levels. Many Canadians turn to supplements, and studies show that those who do are far more likely to have adequate levels. Fortified foods are also a key component of the Canadian strategy to combat insufficiency. Products such as milk, margarine, and some plant-based beverages and cereals are routinely fortified with vitamin D. Natural dietary sources, though fewer, include fatty fish like salmon, mackerel, and sardines, as well as egg yolks and some types of mushrooms.

Comparison of Vitamin D Sources


Source	Pros	Cons
Sunlight	Free and highly effective during summer months.	Ineffective in Canadian winters; risk of skin cancer from excessive exposure.
Diet (Natural)	Whole food sources offer other nutritional benefits.	Few naturally rich foods; limited dietary intake often insufficient on its own.
Diet (Fortified)	Widespread in common foods, making it easy to access.	Content can vary; some people may not consume these specific foods.
Supplements	Reliable and consistent dosage year-round; essential for high-risk groups.	Can be forgotten or inconsistent; dosage requires careful attention to avoid toxicity.

Health Implications of Low Vitamin D

Beyond just bone health, sufficient vitamin D is crucial for overall well-being. Prolonged low levels can lead to a range of complications.

Bone Health: The most widely known effect is on bone mineralization. In children, severe deficiency causes rickets, while in adults it leads to osteomalacia (bone softening) and can contribute to osteoporosis.
Immune Function: Vitamin D plays an important role in immune system function, and deficiency is linked to increased susceptibility to infections and illnesses.
Mental Health: Some research indicates a link between low vitamin D levels and a higher risk of depressive episodes, though studies on supplementation for existing depression are mixed.
Muscle Function: Low levels can increase the likelihood of muscle weakness, pain, and loss of tone, which may lead to a higher risk of falls, especially in older adults.

Conclusion: A Widespread Issue Requiring Proactive Measures

In conclusion, while a majority of Canadians may have sufficient vitamin D levels, a significant portion faces insufficiency or deficiency, particularly during the winter months. Canada's high latitude and climate are primary drivers, but factors like age, skin tone, body weight, and lifestyle also play crucial roles. The reliance on diet alone, even with fortified foods, is often insufficient to meet the body's needs year-round, underscoring the importance of supplements, especially for at-risk populations. Addressing low vitamin D is a key public health challenge that can improve overall bone health, immune function, and mental well-being for many Canadians.

Take Action Against Low Vitamin D

Maximize Safe Summer Sun Exposure: Enjoy 10-15 minutes of unprotected sun exposure on your arms and legs during summer months, but avoid overexposure and use sun protection otherwise.
Integrate Fortified Foods: Incorporate fortified milk, plant-based beverages, and cereals into your daily diet.
Choose Vitamin D-Rich Foods: Increase your intake of fatty fish like salmon, tuna, and mackerel.
Consider Year-Round Supplementation: Especially during the Canadian winter, a daily vitamin D3 supplement is a reliable way to maintain adequate levels, as recommended by Osteoporosis Canada.
Consult a Healthcare Professional: Discuss your specific needs with a doctor, especially if you fall into a high-risk group.

For more information on vitamin D, consult Health Canada's guidelines on nutrient intake.

How to Check Your Vitamin D Status

Recognize Subtle Symptoms: Be aware of potential signs like persistent fatigue, bone or muscle pain, frequent illness, and mood changes.
Request a Blood Test: The most accurate way to check your levels is through a blood test (25-hydroxy vitamin D test) from your doctor.
Monitor Annually: Given the seasonal fluctuations, consider checking your levels annually, particularly at the end of winter.

Frequently Asked Questions

The primary reason is Canada's high latitude, which results in insufficient UVB radiation from the sun during the long autumn and winter months to stimulate vitamin D production in the skin.

According to the Canadian Health Measures Survey, young adults between the ages of 20 and 39 have the lowest rates of sufficient vitamin D compared to other age groups.

No, it is difficult to get enough vitamin D from diet alone in Canada. While fortified foods like milk and fatty fish can help, most Canadians, especially during winter, need to rely on supplements to meet their daily requirements.

Symptoms can include persistent fatigue, bone and muscle pain, muscle weakness, frequent illnesses, and changes in mood. However, low vitamin D can be silent and difficult to diagnose without a blood test.

People with darker skin have more melanin, which reduces the skin's ability to produce vitamin D from sunlight. This places them at higher risk of deficiency and makes year-round supplementation more important, especially in Canada.

In Canada, relying on sunlight is unreliable for much of the year due to the high latitude. Supplements are a safer and more consistent option for maintaining adequate levels, especially during winter, as excessive sun exposure poses a risk of skin cancer.

The most accurate way to check your vitamin D levels is through a blood test ordered by a healthcare provider. This test measures the concentration of 25-hydroxy vitamin D in your blood.