Vitamin C and zinc form a foundation for overall health by supporting immune system function. Vitamin D receptors are found in a number of immune cells, including lymphocytes and macrophages, supporting healthy immune cell activation. Elderberry and lemon balm extracts offer immune-supportive anthocyanins, flavonoids and polyphenols. Polysaccharides from arabinogalactan, aloe and maitake provide complementary support for healthy immune activity. Quercetin plays an important role in mast cell function. Astragalus and eleuthero have been added for their adaptogenic potential.