Oct 11, 2025
- During winter in northern climates, sunlight is too weak to trigger vitamin D production, leaving many people — especially those with excess body fat — at risk for deficiency
- A 10-week study found that exercise alone, without supplements or weight loss, helped maintain levels of active vitamin D in overweight or obese adults
- Physical activity altered enzyme activity in fat tissue, boosting the body’s ability to convert stored vitamin D into its usable form and preventing it from being broken down
- People with the most fat tissue saw the biggest improvements in vitamin D activation, showing that exercise is especially important if you're carrying extra weight
- Exercise trains your body to activate and protect the vitamin D it already has, offering a natural way to help maintain vitamin D levels through winter when sun exposure is limited