The Benefits of Calcium and Vitamin D

Studies have linked dairy foods to good bone health, better blood pressure, and protection from cancer. Newer research touts the dairy-food connection to weight loss and diabetes prevention, and the advantages of probiotics, or good bacteria, found in cultured products. How much truth is there to these claims?


Nutrition Superstar

While there's no doubt about dairy's status as a nutrition superstar (it's packed with protein, minerals, and vitamins A, D, B12, and riboflavin), the jury is still out on some of the more recently publicized benefits. Here's some help to sort it all out.

Fighting Diabetes?

Calcium and vitamin D may lower the risk of type 2 diabetes in people with pre-diabetes, says Anastassios Pittas, M.D., assistant professor of medicine in the Division of Endocrinology, Diabetes, Metabolism, and Molecular Medicine at Tufts University School of Medicine in Boston.

In a recent study, Pittas found that participants with pre-diabetes who took vitamin D (700 IU per day) and calcium (500 mg per day) for three years had a smaller rise in fasting blood glucose (0.4 mg/dl) compared with those who took a placebo pill.

"Vitamin D and calcium may have direct effects on the pancreatic beta cells to enhance insulin secretion," Pittas says. "There may also be beneficial effects on insulin resistance, but the mechanisms are not clear."

The bottom line: "It's premature to make a recommendation that people at risk for type 2 diabetes should take vitamin D and calcium," Pittas says. "I recommend the same as for most people--800 IU of vitamin D and 1,200 mg of calcium. Getting these from foods is always preferable." However, it can be difficult to get that amount in your diet. Talk with a physician or nutritionist about whether a supplement is right for you.