Vegan Friendly Promote Bone Health and Boost Immune System with Vitamin D3 | 5000iu Vitamin D3, scientifically known as cholecalciferol, is an essential vitamin that is crucial for bone health, immune function, and even mood regulation. Our supplement provides the necessary dosage for the absorption of calcium and phosphorus, vital for strong bones and teeth. Additionally, Vitamin D3 supports a healthy immune system and may play a role in regulating mood.