What Is Fortified Milk? Benefits and Uses

Fortified milk is cow’s milk that contains extra vitamins and minerals that are not naturally found in milk in significant amounts.

Typically, vitamins D and A are added to milk sold in the United States (1).

However, milk can be fortified with various other nutrients, including zinc, iron, and folic acid (2).

How or if milk is fortified depends on where you live and what nutrients may be lacking in the typical diet of your country. While some countries require fortification of milk by law, this is not the case in the United States (3).

Still, fortified milk is much more common than unfortified milk in the United States.

In terms of uses, fortified milk is utilized in the same way as unfortified varieties, such as for drinking or cooking.

To fortify milk, vitamin A palmitate and vitamin D3 are added. These are the most active and absorbable forms of these nutrients (4, 5).

As they’re heat resistant, these compounds can be added to milk before pasteurization and homogenization, which are heat processes that kill harmful bacteria and improve shelf life (2, 6, 7).

Other nutrients like B vitamins must be added later, as heat can destroy them. However, milk is not typically fortified with B vitamins in the United States (2).

summary

Fortified milk is milk that contains added nutrients. In the United States, milk is often fortified with vitamins A and D, though it’s not required by law.

Fortified milk is a good source of vitamins A and D. Plus, milk is naturally high in several other vitamins and minerals.

The chart below compares the nutrient contents of 8 ounces (240 ml) of fortified and unfortified 2% milk (8, 9):

Both fortified and unfortified milks are highly nutritious.

They also promote bone health due to their high content of calcium and phosphorus, the two primary minerals that comprise bones. In addition, vitamin D in fortified milk boosts your body’s absorption of calcium (10, 11).

What’s more, nearly 30% of the calories in milk come from protein, which your body needs to build healthy muscles and create compounds that help direct bodily processes (12, 13).

summary

Fortified and unfortified milks are highly nutritious and particularly rich in vitamin B12, calcium, and phosphorus. Fortified milk in the United States is also high in vitamins A and D.

Compared with unfortified milk, fortified milk offers several benefits.

Fills nutrient gaps in your diet

Fortification (adding nutrients that a food lacks) and enrichment (reintroducing nutrients lost during processing) were first developed to prevent nutrient deficiency diseases like rickets, a weakening of bones due to vitamin D deficiency (3).

The fortification and enrichment of flour and milk have helped almost eradicate deficiency diseases in developed countries (14).

In addition, fortification is a useful strategy to correct other micronutrient deficiencies that may not be as serious but can still be harmful (15).

For instance, most people around the world get enough vitamin D to prevent rickets but not other harmful side effects of vitamin D deficiency, such as decreased immunity (16, 17, 18).

One study found that countries with widespread use of fortified milk had populations with higher vitamin D intake and blood vitamin D levels than countries that didn’t widely use fortified milk (19).

Promotes healthy growth in children

Fortified milk helps prevent iron deficiency anemia in children, a common problem, especially in developing countries. In these regions, milk is often fortified with iron and other nutrients, such as zinc and B vitamins.

One review of studies in over 5,000 children found that milk and grain foods fortified with iron, zinc, and vitamin A decreased the occurrence of anemia by over 50% in children younger than 5 years old (20).

In another study conducted in Pakistan, folic-acid-fortified milk helped improve the iron status of toddlers, compared with unfortified cow’s milk (21).

A similar study in the United Kingdom noted that toddlers who drank fortified milk consumed more iron, zinc, vitamin A, and vitamin D and had higher vitamin D and iron levels than those drinking unfortified cow’s milk (22).

Additionally, fortified milk may improve brain function in older children (23).

In one study in 296 Chinese middle school students, those who drank fortified milk were less likely to have riboflavin and iron deficiency. Plus, they showed improved academic performance and motivation, compared with those drinking unfortified milk (23).

However, keep in mind that the nutrients milk is fortified with depend on the regional needs of certain populations. Typically, milk in the United States is not fortified with iron, folic acid, zinc, or riboflavin.

Improves bone health

Fortified milk may help improve bone health. Consuming milk and dairy foods, which are often fortified, is associated with higher bone mineral density, or stronger, thicker bones (24, 25).

Milk is naturally high in calcium and phosphorus, and bone is made of a matrix of these two nutrients (11).

Therefore, even unfortified milk may promote bone health by providing the raw materials needed to create and strengthen your bones (11).

However, vitamin-D-fortified milk, in particular, is excellent for bone health, as this nutrient helps your body absorb more calcium (10).

Proper calcium intake is essential for preventing osteoporosis, a disease characterized by weak and brittle bones. Fortified milk is a low-cost and easily accessible way to get enough calcium and boost your absorption of this important mineral (26).

summary

Fortified milk helps prevent nutrient deficiencies, promote healthy development in children, and increase bone mass and strength.

Though fortified milk is very beneficial, there are some potential downsides to consider.

Researchers estimate that about two-thirds of the world’s population is lactose intolerant and thus unable to properly digest the sugar found in dairy. People with this condition often experience diarrhea and other intestinal issues after consuming milk or dairy (27).

If you’re lactose intolerant or react badly to dairy products, you should avoid fortified milk or choose lactose-free products. If you have a milk allergy, you should avoid dairy products completely.

However, you can choose fortified nondairy milk alternatives, such as soy or almond milk.

In addition, fortification does not necessarily mean that a food is healthy.

For example, chocolate milk can be fortified with vitamins A and D just like white milk. Yet, it’s often loaded with sugar and additives and should be enjoyed in moderation (28).

Finally, choosing fat-free fortified milks may hinder the absorption of vitamins A and D. These vitamins are fat-soluble and need fat while they’re being digested to be fully absorbed (4, 5).

summary

Many people are lactose intolerant and should either avoid dairy or choose lactose-free products. Plus, fortified foods may not necessarily be healthy, and consuming fat-free milk may prevent your body from adequately absorbing fat-soluble vitamins.

Fortified milk contains added nutrients.

In the United States, milk is commonly fortified with vitamins A and D. However, depending on where you live, milk may be fortified with other nutrients or left unfortified.

Fortification may help fill nutrient gaps, prevent iron deficiencies in children, and increase bone density and strength.

Still, if you’re lactose intolerant or have a dairy allergy, you should choose lactose-free or nondairy alternatives.