For years we've been told "drink milk for strong bones."

Now there's more research suggesting Vitamin D may also lower your risk of death from heart disease, cancer, and diabetes.

Monday's study in the Archives of Internal Medicine isn't new. It's part of a growing body of evidence showing just how important Vitamin D is to our health.

We know Vitamin D, in foods like milk, fish, even juice, prevents osteoporosis, brittle bones. But now there's new evidence it may also help keep you alive.

Johns Hopkins Researchers tracked more than 13,000 patients for eight years.

Former Johns Hopkins Researcher Dr. Michal Melamed of the Einstein College of Medicine says "the people who had the lowest vitamin D levels back in 1988 to 1994 had a 26% higher chance of dying."

Why?

Besides making bones strong, Vitamin D also affects the immune system.

Dr. Melamed says "it can tell a cell either to grow or to not grow and it can tell immune cells whether to turn on or not turn on."

So if you don't have enough, those immune cells that prevent disease may not turn on. And while dairy products may be the most well-known source of Vitamin D scientists say most of us get all we need from the sun.

Dr. Melamed says "10 to 15 minutes a day of direct sunlight can probably provide enough vitamin D to not be Vitamin D deficient."

People who spend most of their time indoors, the elderly, overweight adults, dark-skinned Americans, and breastfed babies face the highest risk.

Fortunately, it can be a fun problem to fix.

Of course, any dermatologist will tell you, hanging out in the sun without sunscreen isn't healthy either. You might wonder, won't sunscreen block Vitamin D? Yes, but experts say most of us use it so ineffectively (we dont' put on enough or reapply) that we get plenty of Vitamin D even with sunscreen.