UTMB Dr. Sungmi Lian wrote that, despite vitamin D fortification in food, vitamin D deficiency is still a major health concern, especially for women and the older population. One half of the world population is estimated to be at risk of vitamin D insufficiency. Typically, we get most of our vitamin D from sun exposure and dietary sources, but a supplemental source is becoming essential due to an increased risk of skin cancer and skin photoaging with sun exposure and inconsistent dietary intake of vitamin D in food. Medical experts have been widely promoting vitamin D and calcium supplementation for fall prevention and osteoporosis for a long time; however, beneficial effects of optimal vitamin D level are expanding. (Link unavailable.)