To prevent widespread nutrient deficiencies caused by a national diet dominated by refined goods, the FDA requires that many, but not all of the nutrients removed during refinement be added back, a process called “enrichment.” Iron, thiamine (B1), riboflavin (B2) and niacin (B3), all lost in the making of refined flour, are replaced with synthetic versions at the end of the manufacturing process. Other lost nutrients that we’re aware of, such as magnesium, zinc, vitamin E and selenium, are not replaced.
“Fortification,” on the other hand, occurs when nutrients not naturally found in a particular food are added to that food. Some fortification, such as the addition of folic acid to cereals and other grain products, or vitamins A and D to milk, is mandatory because a nutrient shortfall has been identified as a public-health problem. Other fortifications, such as the addition of calcium to orange juice, iodine to salt, or multiple vitamins and minerals to breakfast cereals, are optional.
—Sylvia M. Geiger, M.S., R.D.