Dr. Michael Holick, director of the General Clinical Research Center and the Vitamin D, Skin and Bone Research Center at the Boston University School of Medicine, published an article in the international medical journal The Lancet in January. In countries where some foods are fortified with vitamin D, the assumption is that dietary fortification is more than adequate to satisfy everyone's requirement for the vitamin.
Little recognition is given to sunlight as the major source of Vitamin D for most people.
Publicity about risk of skin cancer with exposure to sunlight has lead to the wide spread avoidance of exposure to the sun. Consequently, Vitamin D insufficiency has become epidemic in adults over the age of 50 years. Holick reviews several respected journal articles supporting his case. With adequate exposure to sunlight, dietary Vitamin D becomes unnecessary. It is remarkable how exposure to sunlight a few times a week can reduce the risk of osteoporosis, osteomalacia, muscle weakness, fractures and maybe some of the common cancers, but also induce a feeling of well being.