Vitamin D3 is a type of vitamin D that can be naturally produced in the body from animal-based foods and sun exposure. It has better bioavailability and half-life than vitamin D2, and may help with bone health, blood pressure, and osteoporosis. Vitamin D also plays a crucial role in bone growth, remodeling, and regulation of muscle contractions. It is commonly referred to as the “sunshine vitamin” because the D3 type can be naturally produced in the body following exposure to the sun, often in the winter months, we tend to run low on Vitamin D3 thus making us feel sluggish and ran down.