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

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.