Many studies have reported that including fruits and vegetables as a significant part of the overall diet is beneficial to bone health. There may be many components of fruits and vegetables responsible for this. Researchers at the University of Toronto reported that lycopene, found mostly in tomato products, slows bone breakdown rates and likely helps to reduce the risk of osteoporosis.

They studied 33 postmenopausal women and found that those with the greatest intake of lycopene from their diet had the lowest blood levels of markers of bone loss. On average, those with the lowest rates of bone loss consumed daily the amount of lycopene present in about two tablespoons of tomato sauce or catsup.

Lycopene is absorbed by the body more efficiently from cooked tomato products than it is from fresh tomatoes. Also, the presence of some fat in the meal increases the intestinal absorption of lycopenes.

So, pizza looks rather good as a food for bones: cheese provides the calcium along with some fat to enhance the absorption of lycopene from the tomato sauce. As part of a diet with plenty of overall variety, you and your bones can feel good about enjoying pizza and other foods made with tomato sauces. Hold the mayo, extra catsup please!

Source
Rao, Leticia G. et al. “Lycopene Consumption Decreases Oxidative Stress and Bone Resorption Markers in Postmenopausal women.” Osteoporosis International 18 (2007): 109-15. (See article abstract)