Chapter 10 – When to Start with Cow’s Milk

Cow’s milk is rich in energy, protein, and calcium, making it a valuable component of the diet for adults and children. However, it is not suitable as a substitute for breast milk during the first year of life. It contains less iron than human milk, and the small amount it does have is poorly absorbed due to interference from calcium and casein at the intestinal level. Additionally, because its proteins are less digestible than those in breast milk, cow’s milk can cause colitis and minor bleeding in the intestinal mucosa in infants, leading to hidden blood loss in the stool and a further depletion of iron stores.

Several studies have shown that infants fed primarily with cow’s milk during their first year of life are at greater risk of iron deficiency compared to those fed with human milk or infant formula (15).

Moreover, cow’s milk is high in mineral salts. Filtering them places a heavy burden on the kidneys of a small child. Under normal physiological conditions, after the age of one, this strain typically does not pose a health risk. However, in situations involving fluid loss, such as with fever or diarrhea, the added stress on the kidneys increases the risk of dehydration.

Finally, the excessive protein concentration (in relation to a baby’s needs) in cow’s milk may contribute to a greater risk of becoming overweight later in life.

For these reasons, according to experts from the World Health Organization and Italy’s Ministry of Health, cow’s milk and its derivatives may be introduced in small amounts as part of complementary feeding starting at 6 months. However, it should not be offered as the main milk source to replace breast milk within the first year of life (16). Some pediatric specialists and scientific societies go even further and recommend waiting until 24 to 36 months of age before including cow’s milk as a significant part of the diet.