Dr. Michael Holick is one of the great sunlight scientists and has been instrumental in establishing the necessity of sunlight exposure as the best way to receive adequate vitamin D. He is also one of the few proponents among dermatologists for tanning beds as health devices. In a recently published scientific paper, Dr. Holick states, “There needs to be a renewed appreciation of the beneficial effect of moderate sunlight for providing all humans with their vitamin D requirement for health.” Of course, vitamin D is not the only healthful photoproduct delivered by the skin after exposure to sunlight, but it is exceptionally important. The abstract below is a concise and accurate summary of the need for sunlight and vitamin D, as written by this enlightened scientist.
Adv Exp Med Biol. 2014;810:1-16.
Sunlight, ultraviolet radiation, vitamin D and skin cancer: how much sunlight do we need?
Vitamin D is the sunshine vitamin for good reason. During exposure to sunlight, the UVB photons enter the skin and photolyze 7-dehydrocholesterol to previtamin D3 which in turn is isomerized by the body’s temperature to vitamin D3. Most humans have depended on sun for their vitamin D requirement. Skin pigment, sunscreen use, aging, time of day, season and latitude dramatically affect previtamin 13 synthesis. Vitamin D deficiency was thought to have been conquered, but it is now recognized that more than 50% of the world’s population is at risk for vitamin D deficiency. This deficiency is in part due to the inadequate fortification of foods with vitamin D and the misconception that a healthy diet contains an adequate amount of vitamin D. Vitamin D deficiency causes growth retardation and rickets in children and will precipitate and exacerbate osteopenia, osteoporosis and increase risk of fracture in adults. The vitamin D deficiency has been associated pandemic with other serious consequences including increased risk of common cancers, autoimmune diseases, infectious diseases and cardiovascular disease. There needs to be a renewed appreciation of the beneficial effect of moderate sunlight for providing all humans with their vitamin D requirement for health.
Well said, Dr. Holick. Let’s all press forward in helping humanity to recover the health that has been lost through avoidance of the sun, our life-giving friend.