Extensive literature search and review as preparatory work for the evaluation of the essential composition of infant and follow-on formulae and growing-up milk
This systematic review summarises health effects of infant formulae, follow-on formulae or growing-up milks with specified composition compared to other formula with modified composition (objective 1) or breast milk (objective 2). Furthermore, this review presents data on nutrient deficiencies in otherwise healthy European populations aged 0-36 months (objective 3). PubMed was searched to identify publications since 2000 and completed by grey literature and hand search. For objective 1, 4 reviews and 30 original research publications were included and for objective 2 we included 23 original research publications. Results showed no disadvantage nor a clear benefit on health or nutrient status of infant formula with reduced protein content (n=6). Publications on infant formula supplemented with long chain polyunsaturated fatty acids (2 reviews, 11 original publications), pre/probiotics (2 reviews, 2 original publications), nucleotides (n=4), cholesterol (n=2), β-palmitate (n=2), palm oil (n=1) and selenium (n=1) did not show a clear benefit as compared to control formula. Modification of iron (n=2) or lactose (n=2) content of infant formulae did not affect iron status or growth, respectively. Results on comparisons of formula (standard n=10, supplemented n=13) with breast milk showed that growth velocity was higher among formula-fed infants than for breast fed infants, but no further significant differences in clinical outcomes were observed. From grey literature we identified 3 guidelines and directives concerning minimum and maximum levels of nutrients in infant and follow-on formula. For objective 3, 28 publications were extracted on the prevalence of deficiencies of iodine (n=1), iron (n=12), vitamin D (n=4), vitamin K (n=3), multiple nutrients (n=3), and undernutrition (n=5). From grey literature, we obtained data on the prevalence of anemia (n=4), iodine deficiency (n=1), undernutrition (n=14) and inadequate nutrient intakes (n=1). Results for objective 3 showed that in general, good peer-reviewed data on nutrient deficiencies in infants are scarce. Reasons for differences in prevalence of deficiencies, besides basic diet, appear to be national supplementation and fortification strategies, different use of cut-off values for defining deficiency, selection bias in study populations and "real" geographic differences.