Vitamin D is one of the most common nutrient deficiencies I see in my practice. Studies show that 40% of Canadians have insufficient vitamin D blood levels in the winter, and 25% have insufficient levels in the summer (1). This widespread deficiency is concerning, because vitamin D plays such an important role in so many areas of our health. Vitamin D helps maintain calcium homeostasis and healthy bone mineral density, and plays a role in prevention of breast and colon cance