As the sunny seasons fade and temperatures begin to fall, many of us are left wondering how to keep our vitamin D intake sufficient. This essential nutrient is crucial for our overall health, so here are some strategies to maintain optimal levels even when sunlight is scarce.
The Importance of Vitamin D
Primarily known for its role in bone health, vitamin D is also essential for boosting immune function, facilitating muscle movement, and enabling nerve communication between the brain and the body.
Olivia Rose, ND, clinic director at Rose Health Clinic in Scarborough, Ontario, points out that recognizing a vitamin D deficiency can be challenging. Symptoms are often subtle or easily overlooked, including:
- changes in mood
- cognitive difficulties
- seasonal affective disorder
- skin conditions like eczema
- increased susceptibility to colds and allergies
“Vitamin D acts more like a prohormone than a typical vitamin. Its involvement spans numerous bodily processes, from immune support to mental health and skin health,” explains Rose. “Thus, keeping your levels optimal is vital for good health, making regular checks and suitable supplements essential.”
Maintaining Vitamin D Levels as Days Get Shorter
Statistics Canada reports that individuals are four times more likely to achieve adequate vitamin D levels if they take supplements and nearly double the chance if they include fish in their diet regularly.
Rose emphasizes the importance of monitoring vitamin D levels throughout the year, as many believe they get sufficient levels from sunlight in summer. “In truth, many of us spend limited time outdoors or wear clothing and sunscreens that inhibit vitamin D synthesis,” she states. “By the time autumn approaches and respiratory viruses rise, many people’s levels may already be low, increasing their vulnerability to infections.”
Factors Influencing Vitamin D Levels
Vitamin D is synthesized when UVB rays from sunlight interact with skin, converting a skin component to vitamin D3, which is then processed through the liver and kidneys into calcitriol, the hormonally active form of vitamin D.
Sun Exposure and Vitamin D Absorption
Your risk of vitamin D deficiency increases with higher latitudes due to reduced sunlight exposure. Additionally, factors such as cloud cover, buildings, trees, and air pollution can also limit UV ray penetration and interfere with vitamin D metabolism in the skin.
Skin Type Considerations
Skin type significantly affects vitamin D absorption. A study conducted between 2012 and 2019 in Canada highlighted race as a critical factor, showing First Nations women were notably more likely to have insufficient vitamin D during pregnancy compared to their non-First Nations counterparts.
Influence of Socioeconomic Status
Various socioeconomic factors impact vitamin D absorption, including access to sunny vacations, preference for shaded environments, dietary habits, light exposure, clothing styles, use of sunscreen, smoking habits, and the natural aging process.
Vitamin D Levels Across Canada
Research indicates that approximately 19% of Canadians suffer from inadequate vitamin D levels. During winter, the likelihood of deficiency more than doubles across the country, as most regions, with the exception of the southern tip of Ontario, lie above the 42nd parallel north.
This situation is one of the reasons why vitamin D fortification in milk and margarine is standard in Canada. If your diet lacks sufficient sources of this vitamin, like salmon, tuna, or eggs, consider discussing suitable supplementation with your healthcare provider.
This article was initially featured in the September 2025 issue of Thewindowsclubs magazine.
