(Continued from page 9)

Not only do plants need the sun but humans do too.
• Scientists say that north of the 42nd parallel, or at about Omaha, the sun's energy is insufficient for vitamin D synthesis from November through February. Related is the condition we experience up here called seasonal affective disorder, or the winter blues. It is a real depressive condition due to not enough light, treated simply by giving those effected more exposure to the beams of the sun, or another strong source of light.
• On the other hand, there are disadvantages to too much sun, especially in those light-skinned, red or blonde-

headed, blue-eyed Scandinavian/German/Scotch-Irish type. UV radiation is toxic to the skin and it is the lifetime exposure that counts up. I see the ravages of Ol' Sol on the face of my patients with premature aging and cancers of several types. They come in with excessive wrinkles, sores that don't heal, scales that are turning into little horns, and pigmented spots that are spreading.
• How can something so good be also so bad?
• Bottom line, enjoy the sun, but balance with sun screening, checking vitamin D levels, and seeing your doctor when skin bumps change.
•
•
• Dr. Rick Holm wrote this Prairie Doc Perspective for "On Call®," a weekly program where medical professionals discuss health concerns for the general public.  "On Call®" is produced by the Healing Words Foundation in association with the South Dakota State University Journalism Department. "On Call®" airs Thursdays on South Dakota Public Broadcasting-Television at 7 p.m. Central, 6 p.m. Mountain. Visit us at OnCallTelevision.com.