By Robert Preidt, HealthDay Reporter

• Vitamin D, which is actually a hormone, is created in your body when your skin is exposed to the sun.
• Without the proper amounts of vitamin D, you could be at risk for all kinds of health problems, including heart conditions and weakened bones.
• Children who have vitamin D deficiencies are also at higher risks of developing rickets.

By Amanda MacMillan

Osteoporosis is generally viewed as a woman's disease, but men get it, too. While this fragile bone disease is indeed more common in women, there is increasing recognition that it strikes men more frequently than previously believed. Whereas one in two women will break a bone during their lifetime due to osteoporosis, according to the National Osteoporosis Foundation, one in four men will have an osteoporosis-related broken bone. 

By Jeannette Moninger

Your immune system puts up a pretty good fight against germs and infections, but sometimes your inner warrior mistakenly starts picking on the good guys. When your own defense system mistakenly attacks healthy cells in your body, you end up with an autoimmune disease.