Many experts say that vitamin D is not a vitamin. It is a hormone that our skin creates from sun exposure. This fact is important because, similar to other hormones, vitamin D is crucial for our body and brain to function properly. The right balance of vitamin D makes us feel good physically, intellectually and emotionally. It is necessary for the skin, bone and brain. Furthermore, vitamin D helps in cancer prevention, plays a preventive and curative role in major diseases, is critical for making memories and learning and aids in making people happy. Vitamin D deficiency There is a dramatic rise in the rate of vitamin D deficiency worldwide. According to research, it is estimated that half of the whole population is at risk of vitamin D deficiency and insufficiency. Fifty percent of children aged one to five are vitamin D deficient based on the National Health and Nutrition Examination Survey. Moreover, 70 percent of children aging six to eleven have insufficient or deficient vitamin D levels. Thus, more than half of all children in the US are vitamin D deficient. Moreover, clinical studies also reveal that almost 75 percent of pregnant women are vitamin D deficient. The deficiency puts the unborn children at risk to all types of health problems. In a worldwide scale, vitamin D deficiency affects more than one billion people. The role of sunshine A clinical study involving workers in different fields indicated the role of sunshine in health, mood and productivity. Nurses who were exposed to natural light had lower blood pressure, were more alert, and had better moods when dealing with patients than nurses who were not exposed to sunlight. On the other hand, a study revealed that workers in a windowless workplace had more health problems and worse sleeps habits than those working in windowed workplaces.