Source of Life Garden Vitamin D3 2500IU (60). Plant Sourced Vitamin D3. Nature's Plus Source of Life Garden Vitamin D3 capsules provide 2500IU of Vitamin D3 per serving from a 100% plant source.. Derived from Cholecalciferol, a variety of organic mushrooms with numerous health benefits, the capsules supply essential Vitamin D3, which is vital for immune support and bone support, and a range of other minerals and nutrients which support overall optimum levels of health.