Vitamin D - the Sunshine Vitamin is an essential nutrient that the body creates by converting cholesterol in the body via sunshine. However, today's culture of cubicles, sunscreen, and near-round-the-clock indoor living minimizes our exposure to natural sunlight for the needed period of time for sufficient Vitamin D to form. Supplementing with Nature's Bounty Vitamin D3 is an easy way to increase your daily intake of this important nutrient. Product Benefits. Supports strong bones and immune system.