When daylight gets shorter in Victoria, BC, conversations about vitamin D tend to pick up. Can the “sunshine vitamin” improve your workouts? Could low levels affect muscle strength? And does exercising outdoors provide everything you need?
At BPM Fitness Centre, we believe understanding your body helps you build better habits. Whether you enjoy strength training, group fitness classes or HYROX training, vitamin D deserves attention. Its role in exercise is important, but the science is more nuanced than supplement marketing suggests.
What Does Vitamin D Do?
Vitamin D is a fat-soluble nutrient that your body obtains through certain foods, supplements and production in your skin following ultraviolet B exposure. Your liver converts it into 25-hydroxyvitamin D, the form commonly measured in blood tests. Your kidneys then help produce its active hormonal form.
This active form helps regulate calcium and phosphorus, supporting normal bone mineralization. Vitamin D also contributes to neuromuscular and immune function. These processes help maintain the systems your body relies on during exercise.
Think of vitamin D as part of your exercise foundation. It supports normal function, while progressive exercise supplies the challenge that drives fitness improvements.
Why Vitamin D Matters for Canadians
Living on Vancouver Island means enjoying outdoor opportunities throughout the year. However, spending time outside does not guarantee adequate vitamin D production.
Season, cloud cover, time of day, clothing and limited outdoor time can affect how much vitamin D your skin makes. Older adults produce less, while greater skin pigmentation reduces production under equivalent conditions. Health Canada therefore recommends getting vitamin D from food or supplements every day.
For Canadians balancing indoor work, early morning workouts and winter clothing, a deliberate nutrition routine makes sense. Keep enjoying outdoor movement and practising sun safety; use dietary sources and appropriate supplementation to address vitamin D intake.
Vitamin D, Muscle Strength and Athletic Performance
Vitamin D deficiency can contribute to muscle weakness. However, that does not mean taking extra vitamin D automatically builds stronger muscles when your levels are already adequate.
Research on vitamin D supplements and athletic performance remains mixed. A 2023 meta-analysis of randomized controlled trials found no statistically significant overall improvement in athletes’ maximal strength or power. Researchers also highlighted limitations in the available studies, including differences in participants and supplementation protocols.
The practical message for BPM members is straightforward: correcting a deficiency matters for health, but supplements cannot promise a heavier squat or faster HYROX finish.
For strength gains, keep prioritizing progressive resistance training, adequate food, protein, sleep and consistency. Our personal training can help you develop an exercise plan that matches your starting point and goals.
How Vitamin D and Exercise Supports Bone Health
Your bones constantly remodel, responding to both nutritional resources and physical demands. Vitamin D helps your body absorb calcium, providing support for maintaining their mineral structure. Severe deficiency can cause osteomalacia, a condition involving poorly mineralized bones in adults.
Nutrition and exercise therefore belong in the same conversation about lifelong strength. At BPM, movements such as squats, carries and appropriately progressed resistance exercises can form part of a broader training routine.
Explore our group fitness classes to find coaching and a format that helps you stay consistent.
How Much Vitamin D Do Canadians Need?
Canadian recommended dietary allowances describe total daily intake from food and supplements:
- Adults aged 19–70: 600 IU, or 15 micrograms.
- Adults over 70: 800 IU, or 20 micrograms.
These values assume minimal sun exposure.
Health Canada’s practical supplement advice is slightly different: adults up to age 50 should eat vitamin D foods daily or take a supplement containing 400 IU. Adults aged 51 and older should take a daily 400 IU supplement while continuing to include dietary sources. The supplement amount and total daily requirement describe different things.
Training hard does not automatically establish a need for higher doses. A pharmacist, registered dietitian or physician can help you apply these recommendations to your circumstances.
Food First, With Supplements When Appropriate
Useful vitamin D sources include salmon, trout, egg yolks, milk and fortified plant-based beverages. Check labels, particularly when choosing dairy alternatives, because fortification varies.
Practical options include a smoothie made with fortified soy beverage, salmon with rice after training, or eggs alongside your usual breakfast. Build these choices into meals that also provide enough overall energy. BPM’s article on nutrition needs when training hard explores that bigger picture.
Should You Get Your Vitamin D Tested?
Routine vitamin D testing is generally not recommended for otherwise healthy adults. Testing may be appropriate when a clinician identifies a specific medical reason. Persistent weakness, bone pain or unexplained fatigue deserves assessment rather than an assumption that vitamin D is responsible.
At BPM Fitness Centre, our approach connects consistent exercise with sustainable habits. Meet your nutritional needs, seek individualized medical advice when needed, and keep showing up for training that supports your strength, confidence and long-term health.
References
- Sist, M., Zou, L., Galloway, S. D. R., & Rodriguez-Sanchez, N. (2023). Effects of vitamin D supplementation on maximal strength and power in athletes: A systematic review and meta-analysis of randomized controlled trials. Frontiers in Nutrition, 10, Article 1163313. https://pubmed.ncbi.nlm.nih.gov/37841405/
- Han, Q., Xiang, M., An, N., Tan, Q., Shao, J., & Wang, Q. (2024). Effects of vitamin D3 supplementation on strength of lower and upper extremities in athletes: An updated systematic review and meta-analysis of randomized controlled trials. Frontiers in Nutrition, 11, Article 1381301. https://pubmed.ncbi.nlm.nih.gov/38860160/
- Bislev, L. S., Grove-Laugesen, D., & Rejnmark, L. (2021). Vitamin D and muscle health: A systematic review and meta-analysis of randomized placebo-controlled trials. Journal of Bone and Mineral Research, 36(9), 1651–1660. https://pubmed.ncbi.nlm.nih.gov/34405916/
