Nature’s Bounty Vitamin D3 25mcg (1000 IU) is a daily supplement designed to support bone strength, immune function, and overall wellness. It provides vitamin D3  the form your body naturally produces when exposed to sunlight. Vitamin D3 aids in calcium absorption, essential for maintaining strong bones and teeth. It plays a crucial role in modulating the immune response, helping to defend against pathogens. Vitamin D3 supports muscle function and nerve signaling, contributing to overall neuromuscular health.