Vitamin D3
Vitamin D3 - (Cholecalciforol or Calciol) acts as both a vitamin and a hormone. It acts as a vitamin when it binds with calcium for proper absorption. Humans have difficulty digesting calcium without Vitamin D3. This is why Vitamin D is so often added to products such as Milk.
Vitamin D3 deficiency can result in High Blood Pressure, Depression, Type 2 Diabetes, Osteoporosis, Fibromyalgia, and even Alzheimer's. It is a wonder that with all our medical advances, Vitamin D3 deficiency is still an epidemic.