Vitamin D is called the Sunshine Vitamin because it is produced naturally by the body after exposure to approximately 1/2 hour of sunlight. The amount of Vitamin D produced is dependent on such variables as skin type and time of day. Many people develop Vitamin D deficiencies due to a lack of sun exposure and other reasons. Vitamin D is most well known for its contribution to supporting bone health by helping the body absorb calcium*. Adequate Vitamin D levels help maintain healthy bones throughout our life cycle. Vitamin D3 is used to help support a healthy immune system and support bone health.