New methods to add more iron to dairy products could help millions of Americans avoid iron deficiencies without shortchanging them of essential calcium, Utah State University researchers say.

Adding an iron-milk protein complex to milk used to make cultured dairy products such as cheese and yogurt increased the iron levels without creating any of the off-flavors previously associated with iron, say scientists at USU's state agricultural experiment station.Dairy products contain little iron but are a rich source of calcium and vitamin D. As a result, diets that contain enough calcium are often deficient in iron, and vice versa.

Iron deficiencies are especially common among women of childbearing age, pregnant women and young children, and among low-income groups. A shortage of calcium increases the risk of osteoporosis and hypertension.

"We can increase the iron content of cultured dairy products to at least 18 milligrams per 2,000 calories, the recommended daily allowance of iron and calories for women," said food scientist Art Mahoney, who developed the iron-fortification procedure. Even higher iron-fortification levels are possible.

Food scientists testing the technique did not detect any off-flavors in cheese made from iron-fortified milk. Studies also indicate that the iron is "at least as bioavailable as in foods such as meat, which is a good source of iron, and in iron supplements," Mahoney said.

Mahoney said additional research is required, and that it may be several years before the technique will be perfected and approved for production.

But, he added, the iron-fortified dairy products promise to be particularly useful in school lunches for children and free dairy commodities for low-income recipients.

The research was supported by the Utah Agricultural Experiment Station and the National Dairy Promotion and Research Board through the Western Dairy Foods Research Center.