Today Vitamin D is considered more important than ever. Vitamin D3 a potent and bio-available form of Vitamin D plays an active role in the absorption of Calcium and Phosphorus the building blocks of bone health.* With concern about the damage of long term sun exposure many of us are not getting the Vitamin D we need from natural sunlight. Non-Acidic Ester-C with D3 Bone & Immune Health Complex combines the advanced active immune system support of pH-neutral Ester-C Vitamin C with high-potency (5000 IU) Vitamin D3 in a once daily formula.*Other products from HerbsPro