Science-Based Nutrition™Supports Heart, Bones, & Immunity Dietary SupplementNon-GMO · Gluten Free · Soy Free At Doctor's Best, we strive to deliver a sunny vitality boost. Our Vitamin D3 formula provides this essential sunshine nutrient, promoting overall health when dietary intake and sun exposure are limited. Cholecalciferol, known as Vitamin D3, plays a key role in supporting a healthy immune system, heart function, and maintaining strong bones. Supports healthy immune system.Regulates calcium and phosphorus for strong bones.Supports heart health.