Fortification is the process by which manufacturers add micronutrients such as vitamins and minerals to food. The purpose is to reduce the rate of common deficiencies and diseases that would otherwise occur in the absence of these nutrients. This is especially important in regions where the soil — and thus the plants that grow in the soil — is nutrient poor. Though fortification is sometimes optional, the federal government mandates the inclusion of certain nutrients in cereal, salt and even milk because of concerns over public health.
Vitamin A and vitamin D are the two nutrients that federal regulations mandate for the fortification of milk. Vitamin A is a nutrient that the human body requires for vision and gene transcription. Vitamin D promotes calcium absorption and enhances immune system activity. However, individual manufacturers may choose to fortify milk with additional nutrients such as essential minerals or omega-3 fatty acids. Soy and almond milk, which are made from plants, often undergo a process of fortification to match the nutrient content found in cow's milk.
The developmental childhood period is the most important period for proper nutrition. An estimated 250 million preschool children are afflicted with vitamin A deficiency worldwide, according to the World Health Organization. In its most pernicious form a deficiency can lead to vision loss followed by death. Though rarer in the developed world, deficiencies were more common before public health efforts such as widespread food fortification began in the early 20th century. Some physicians have expressed concern that fortification may lead to unsafe doses of vitamins and minerals — though a normal healthy adult would have to drink dozens of quarts of milk per day over a consistent period of time to reach the tolerable upper limit of vitamin A and vitamin D.
Amount of Vitamins Added
Milk manufacturers must add at least 2,000 IU of vitamin A per quart and 400 IU of vitamin D per quart. IU stands for international unit, which measures the amount of a substance based upon its biological activity or effect. The IU is different for each nutrient. However, the amount of vitamin A and vitamin D that manufacturers must add to milk represents 10 percent and 25 percent of the daily value, respectively.
One benefit of fortification is that it allows the vitamin D to naturally improve the absorption rate of the calcium that already exists within milk. Vitamin D is important for strong bones. It promotes the proper skeletal calcium balance and maintains calcium levels in the blood. Consuming an adequate amount of calcium and vitamin D in your diet is essential for preventing a deformity or softening of the bones such as rickets in children and osteomalacia in adults. It may also diminish or prevent the onset of osteoporosis in the elderly.