Vitamin D is often called the “sunshine vitamin,” yet deficiency is increasingly common — even in sunny countries like India. Modern indoor lifestyles, sunscreen usage, and poor dietary habits have contributed to rising Vitamin D deficiency across all age groups. At Lee Health Domain , we emphasize preventive awareness because optimal Vitamin D levels play a crucial role in immunity, bone health, mood stability, and overall vitality. What Is Vitamin D and Why Is It Important?