More Than Bone Deep: How Vitamin D Deficiency Quietly Dismantles Immune Defense and Mental Clarity
Vitamin D deficiency is far more consequential than its association with brittle bones suggests, with emerging research linking chronically low levels to immune dysregulation, heightened autoimmune risk, and measurable declines in mood and cognitive function. Standard blood panels frequently fail to flag suboptimal levels, leaving millions of Americans unaware that a correctable deficiency may be quietly undermining their health. Understanding the full scope of vitamin D's biological role—and kn