Age of introduction of first complementary feeding for infants: a systematic review.
BACKGROUND
Despite a World Health Organization recommendation for exclusive breastfeeding of all full-term infants to 6 months of age, it is not clear what the health implications may be. Breast milk alone may not meet the nutrition needs for all growing infants, leaving them at risk for deficiencies. The objective of this study was to investigate the relationship between moderate (4 months) versus late (6 months) introduction of complementary foods to the full-term breastfed infant on iron status and growth.


METHODS
An electronic search of peer-reviewed and gray-literature was conducted for randomized control trials (RCTs) and observational studies related to the timing of introduction of complementary foods. Iron status and growth data from the relevant RCTs were analyzed using RevMan 5.2.11.


RESULTS
Three RCTs and one observational study met the inclusion criteria. Meta-analysis showed significantly higher hemoglobin levels in infants fed solids at 4 months versus those fed solids at 6 months in developing countries [mean difference [MD]: 5.0 g/L; 95% CI: 1.5, 8.5 g/L; P = 0.005]. Meta-analysis also showed higher serum ferritin levels in the 4-month group in both developed and developing countries [MD: 26.0 μg/L; 95% CI: -0.1, 52.1 μg/L, P = 0.050], [MD: 18.9 μg/L; 95% CI: 0.7, 37.1 μg/L, P = 0.040]. Short follow-up periods and small sample sizes of the included studies were the major limitations.


CONCLUSIONS
RCT evidence suggests the rate of iron deficiency anemia in breastfed infants could be positively altered by introduction of solids at 4 months.
Department of Human Nutritional Sciences, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada. wafaaqasem@yahoo.com.|Richardson Centre for Functional Foods and Nutraceuticals, 196 Innovation Drive, University of Manitoba, Winnipeg, MB, R3T 6C5, Canada. wafaaqasem@yahoo.com.
Wafaa
W
Qasem
Nutrition Services, Alberta Health Services, Alberta Children's Hospital Research, Institute, Department of Community Health Sciences, University of Calgary, TRW Building, 3280 Hospital Dr NW, Calgary, AB, T2N 4Z6, Canada. tfenton@ucalgary.ca.
Tanis
T
Fenton
Department of Human Nutritional Sciences, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada. James.Friel@umanitoba.ca.|Richardson Centre for Functional Foods and Nutraceuticals, 196 Innovation Drive, University of Manitoba, Winnipeg, MB, R3T 6C5, Canada. James.Friel@umanitoba.ca.
James
J
Friel
D000367:Age Factors; D018798:Anemia, Iron-Deficiency / Q000517:prevention & control; D001942:Breast Feeding; D002657:Child Development / Q000502:physiology; D003906:Developing Countries; D005293:Ferritins / Q000097:blood; D006128:Growth / Q000502:physiology*; D006801:Humans; D007223:Infant; D007225:Infant Food; D007227:Infant Nutritional Physiological Phenomena; D019266:Iron, Dietary / Q000008:administration & dosage / Q000097:blood*
D019266:Iron, Dietary; D005293:Ferritins