What is the difference between vitamin D, D2, and D3?

    Vitamin D is a nutrient that plays an important role in maintaining bone health, supporting the immune system, and regulating mood. It comes in two main forms: vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). Understanding the differences between these two forms is essential to optimizing your health.

    Vitamin D3 is naturally synthesized in your skin when exposed to sunlight, specifically ultraviolet B (UVB) rays. It is also found in animal-based foods such as egg yolks, fatty fish like salmon and mackerel, and fortified dairy products. On the other hand, vitamin D2 is typically derived from plant sources, including yeast and mushrooms exposed to ultraviolet light, making it a popular option for vegetarians and vegans.

    Both forms are available as dietary supplements and are often added to fortified foods.

Vitamin D3 is significantly more effective than D2 at increasing blood vitamin D levels, showing a 40% greater increase in total vitamin D concentrations with supplementation.

    Natural sunlight exposure remains the optimal source of vitamin D, but factors such as skin color, geographic location, and body composition affect individual vitamin D synthesis.

    Global vitamin D deficiency affects approximately 76.6% of the population, impacting bone health, immune function, mental health, and chronic disease risk.

    For optimal health benefits, maintain vitamin D levels between 60 and 80 ng/mL through a combination of sensible sun exposure and vitamin D3 supplementation when needed.