Researchers from Massachusetts General Hospital Weight Center in Boston randomly assigned 171 obese patients to drink plain orange juice or orange juice spiked with calcium and vitamin D. They found similar weight loss between the two groups; however, the patients who drank the juice with the calcium and vitamin D had significantly greater reductions in stomach fat compared to the patients who drank the juice without the extra nutrients. They published their data in the January 2012 issue of the American Journal  of Clinical Nutrition.

This is a key finding because research shows that excess belly fat increases the risk of cardiovascular disease, type 2 diabetes and colorectal and breast cancers.

The study participants drank about 8 ounces of juice three times a day. The fortified juice contained 350 mg of calcium and 100 IU of vitamin D per serving. This study lasted 16 weeks, and the average weight loss among both groups was just over five pounds. However, researchers found the highest waistline reduction in the plain juice drinkers was just under 14 cm, compared to 25 cm in the calcium-vitamin D juice drinkers.

Previous studies have shown that people whose diets are higher in calcium are less likely to be overweight. Vitamin D aids the absorption of calcium, which may explain its effects. The Natural Standard Research Collaboration concludes, “While more research is needed to understand the relationship between calcium intake and body fat, these findings [from the combined research] emphasize the importance of maintaining adequate calcium intake while attempting to lose weight.”

Milk, yogurt and cheese contain high amounts of calcium, but they are also high in fat. Kale is an excellent, healthy source of calcium, as is salmon and some nuts such as almonds. Vitamin D is found in fish, milk and mushrooms.