Big Friends Liquid Vitamin D3 is carefully blended in a mixture of medium chain triglycerides (sourced from certified sustainable palm and coconut oil) and flaxseed oil providing 10 mcg (400 IU) of vitamin D3 in just one little drop. Vitamin D3 is essential for strong bones and teeth as it increases the body’s absorption of calcium from food.* Its role in regulating calcium levels also helps regulate the immune system and maintain healthy nerves and muscles.*