Our Vegan Vitamin D-3 is derived from sustainably sourced lichen instead of sheep's wool, making a great vegan source of vitamin D-3. Many adults don't get enough vitamin D through diet - or get adequate sunlight - so adding vitamin D-3 to your regimen is a great way to make sure you get the support you need for healthy bones and teeth. Vitamin D also enhances calcium absorption and is essential for bone mineral density.