Effect of fortified milk on growth and nutritional status in young children: a systematic review and meta-analysis

Abstract

Objective: Adequate nutrition is critical for optimal growth and development. However, young children may be at risk of nutrient deficiencies when transitioning to weaning foods for a variety of reasons. Supplementation with fortified milk may provide potentially lacking essential nutrients, but effects on growth and nutritional status are yet to be established.

Design: Five databases were searched for randomised controlled trials using fortified milk against control milk in young children. Outcomes were growth, body composition and/or biochemical markers. Pooled differences in means were calculated for continuous outcomes and odds ratios for binary outcomes.

Setting: Randomised controlled trials set in any country.

Subjects: Otherwise healthy children aged 6-47 months.

Results: Fifteen articles met the eligibility criteria. Fortification varied from Fe, Zn, vitamins, essential fatty acids, to pre- and/or probiotics. Frequently reported outcomes were weight, height and Fe status. Studies varied in geographical location, sample size and duration. Fortified milk had minimal effects on weight gain (mean difference=0·17 kg; 95 % CI 0·02, 0·31 kg) compared with control milk. The risk of anaemia was reduced in fortified milk groups (OR=0·32; 95 % CI 0·15, 0·66) compared with control groups. There were no significant effects on height gain, changes in body composition or Hb concentration.

Conclusions: Fortified milk is an effective source of complementary nutrition to supplement children in need when consumed in appropriate amounts in addition to a normal diet. Due to compositional differences, further research on fortified milk is warranted before making global recommendations on benefits for growth and nutritional outcomes in young children.

Keywords: Fortified milk; Growth; Iron deficiency; Nutritional status; Young children.

Fig. 1

(colour online) Flow diagram of the study selection process including the relevant number of papers at each stage and reasons for exclusion

Fig. 2

(colour online) Forest plot: effect of fortified milk compared with control milk on mean difference in weight gain (kg) among 6–47-month-old children. The study-specific mean difference and 95 % CI are represented by the black dot and horizontal line, respectively; the area of the grey square is proportional to the specific-study weight to the overall meta-analysis. The centre of the open diamond/vertical dashed line represents the pooled mean difference and the width of the diamond represents the pooled 95 % CI. The solid vertical line represents no effect

Fig. 3

(colour online) Forest plot: odds of anaemia with fortified milk compared with control milk among 6–47-month-old children. The study-specific OR and 95 % CI are represented by the black dot and horizontal line, respectively; the area of the grey square is proportional to the specific-study weight to the overall meta-analysis. The centre of the open diamond/vertical dashed line represents the pooled OR difference and the width of the diamond represents the pooled 95 % CI. The solid vertical line represents no effect