When it comes to vitamins and minerals, HM contains just an ample amount for normal growth of an infant, except for vitamin K and D. Lactose content in HM is approximately 7%, while bovine milk has a lactose content of 4.5%. All these nutritional differences should be modified and modulated in such a way that the infant milk formula thus developed mimics both the structure and composition of mature HM. Table 1 shows a nutrient comparison between bovine milk and HM (per 100 ml).
*ND: No data available; Ahern et al., 2019
The Science of making IMF
Infant milk formulas are the result of decades of scientific research aimed at achieving a precise balance of macronutrients (carbohydrates, proteins, and fats), micronutrients (vitamins and minerals), and bioactive compounds so that they closely approximate the composition of HM. Although donkey milk is considered the closest natural analogue to HM for formulating infant milk, cow milk remains the most widely used base due to its global availability (Bakshi et al., 2023). For infants with cow milk allergy, formulas derived from the milk of other species such as buffalo, goat, sheep, or donkey can serve as suitable alternatives.
Lactose is the predominant carbohydrate in HM. During the manufacture of IMFs, its level is typically adjusted to approximately 7–7.50 g/100 mL to replicate HM composition. However, lactose is not the only carbohydrate present; HM contains nearly 100 distinct HM oligosaccharides (HMOs), which have been associated with improved gut health, reduced infection and inflammation, and enhanced cognitive development (Debnath et al., 2022). HMOs constitute the third most abundant solid component in HM after lactose and lipids (Wejryd et al., 2025). Recognising their well-documented health benefits, Nestlé introduced an HMO-enriched IMF in China in 2023.
For proteins, only the L-form of amino acids is permitted, while the D-form is not allowed because it may lead to D-lactic acidosis (Martin et al., 2016). Whey protein isolates (WPI), skim milk powder (SMP), whey protein concentrates (WPC), and similar ingredients are incorporated into IMFs to achieve the required protein levels (Lagutin et al., 2022). Typically, formulas are manufactured to contain approximately 1.3–1.5 g/100 mL of protein, which is slightly higher than the amount in HM to compensate for essential amino acid needs. Partially or fully hydrolysed proteins and demineralised proteins are also used in IMFs because they enhance digestibility, reduce allergenicity, improve nutritional functionality, and bring the formula closer to HM composition (Drapala et al., 2017). Amino acid-based formulas are developed for infants who are highly allergic to bovine milk proteins (Novak et al., 2019).
Fats serve as the primary source of energy in IMFs, providing nearly half of an infant’s caloric requirements. Long-chain polyunsaturated fatty acids such as arachidonic acid and docosahexaenoic acid are present in much lower amounts in cow’s milk compared to HM (Skolnick et al., 2020). Therefore, formulas must be fortified with these fatty acids to improve digestibility, reduce intestinal inflammation, and make their composition closer to that of HM. According to FSSR (2019), the fat content in IMFs should range between 3.80–5.30 g/100 kcal. A study examining the role of vegetable and bovine milk fats suggests that combining both sources in formula may provide additional benefits (Hageman et al., 2019).
In manufacturing IMFs, enhancing intrinsic minerals is preferred because adding fortified minerals can lead to product instability (Crowley et al., 2017). Minerals such as phosphorus, potassium, calcium, sodium, magnesium, and chloride are added in forms that promote solubility—such as citrates, chlorides, carbonates, phosphates, and hydroxides (Masum et al., 2021). Mineral concentrations must be carefully adjusted in formula milk based on cow’s milk, as its naturally higher mineral levels can increase renal solute load and the risk of dehydration in infants. During IMF manufacturing, ingredients are exposed to high temperatures during pasteurisation, concentration, and spray drying, which can degrade heat-sensitive vitamins like vitamin C and thiamine. Therefore, it is important to compensate for these losses through appropriate fortification (Mc Sweeney et al., 2013).
Beyond basic nutrients, IMFs should include several bioactive compounds that are naturally present in HM. Lactoferrin is one of the most important bioactive proteins, contributing to immune modulation, regulation of iron absorption, and exhibiting antiviral, anti-inflammatory, antimicrobial, and anti-cancer properties (Hao et al., 2019). Osteopontin, found in high levels in HM, supports immune regulation and gene expression, and its supplementation up to 160 mg/L is recommended by the FDA (2017). Other essential components include choline, required for brain development; L-carnitine, critical for fatty acid metabolism; taurine, important for fat absorption and nervous system development; and inositol, which is involved in phospholipid synthesis and helps prevent respiratory complications in preterm infants (Bakshi et al., 2023).
IMF is a scientifically developed alternative designed to closely replicate the nutritional and functional qualities of HM. Although HM remains the ideal standard, advances in dairy technology now allow formulas to provide balanced nutrients and key bioactive components such as HMOs, lactoferrin, and structured lipids. Ongoing improvements in ingredient selection and processing have enhanced the safety and nutritional relevance of these products, despite challenges like allergenicity and heat-sensitive vitamins. With emerging research on oligosaccharides, gangliosides, and miRNAs, future formulas are expected to align even more closely with the complexity of HM, supporting infant nutrition when breastfeeding is not feasible.
(The authors belong to Department of Dairy Technology, College of Dairy and Food Science Technology, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab)