You don't get enough Vitamin D in the winter

[KMSP Fox 9 News, January 08, 2014] The short daylight hours in the winter up north here, plus all the skin-covering clothing we wear, makes it virtually impossible for us to naturally get from the sun all the vitamin D we need.

So says Dr. Greg Plotnikoff of the Penny George Institute for Health and Healing at Allina Health. He talked with Fox 9 News anchor Jeff Passolt about the problem.