Vitamin D: Importance, Deficiency Symptoms, and How to Replenish It
Have you ever wondered why Vitamin D is called the “sunshine vitamin”? Despite its importance, deficiency affects nearly 1 billion people worldwide (WHO, 2023). From bone strength to immunity, mood, and even cardiovascular health, this fat-soluble vitamin plays a much bigger role than most people realize. This article provides a comprehensive overview of Vitamin D: its physiological functions, deficiency symptoms, risk factors, diagnosis, and strategies for supplementation and prevention. What is Vitamin D? Vitamin D is a fat-soluble vitamin that functions more like a hormone. It exists in two main forms: Vitamin D2 (Ergocalciferol): Found in plants and fortified foods. Vitamin D3 (Cholecalciferol): Produced in the skin after sunlight exposure and found in fatty fish and egg yolks. Both forms are metabolized in the liver to 25-hydroxyvitamin D [25(OH)D] , the main circulating form used for diagnosis, and then converted in the k...
