Dr. Eric Berg highlights 12 symptoms of vitamin D deficiency that people may not be aware of. Why are the symptoms of vitamin D deficiency not common knowledge, especially in temperate regions of the world where the Sun’s rays are weaker and, particularly during the winter months, there is less direct sunlight that reaches the ground and even less that reaches our bare skin? Is it because effective vitamin D treatment competes with Big Pharma and will interfere with their profits?