Morning Rounds: Is McDonald's getting healthier?

(CBS News) CBS News chief medical correspondent Dr. Jon LaPook and CBS News contributor Dr. Holly Phillips discussed on "CBS This Morning: Saturday" the major medical stories of the week.

A new partnership for healthy eating, announced by the Clinton Global Initiative and McDonald's is getting a lot of attention. Next year McDonald's customers will be able to substitute fruit, salad or a vegetable for french fries. The developments will be rolled out in many countries, including the United States.

Also, McDonald's has said that advertising directed to children will feature nutrition messages. This is the first time a big player in the food business has made a commitment in the United States to change advertising directed at children.

"It's a very nice first step, especially if you know the history. For years health experts have had a real problem with the fact that so much junk food is marketed to kids, and now for the very first time we're hearing a CEO of major company saying it's a business decision," said LaPook. "They're not doing this out of the goodness of their heart. The consumers are driving this because of a demand. We're seeing this with Burger King, with Subway."

This week there were two important studies about bone health. The first looked at vitamin D, and the other examined how often people should have a bone-density scan. Some nine million Americans live with osteoporosis and more than 48 million are at risk for the condition.

"The study out this week looked specifically at high-dose vitamin D supplements and whether or not they prevent osteoporosis," said Phillips. "One really important aspect of osteoporosis is called bone turnover, and it turns out that even in high doses vitamin D supplements taken by themselves don't help to prevent osteoporosis, but vitamin D plus calcium, when you take that supplement, it does."

For Dr. Jon LaPook and Dr. Holly Phillips' full roundup on this week's medical stories, watch the video in the player above.