Evaluating the relationship between the nutrient intake of lactating women and their breast milk nutritional profile: a systematic review and narrative synthesis.
Level 2 - randomized trial
Systematic review encompassing both randomized and observational studies without meta-analysis due to heterogeneity
PubMed 38053371 · doi:10.1017/S0007114523002775
What was done
Researchers systematically searched PubMed, CENTRAL, Web of Science, and CINAHL through June 4, 2023, to assess the effects of maternal nutrient intake and exclusion diets on breast milk nutrient and contaminant composition. Study quality was evaluated using the Cochrane Risk of Bias tool and the Newcastle-Ottawa scale. The review included 88 studies comprising 6,577 participants, analyzed via narrative synthesis because high heterogeneity precluded meta-analysis.
What was found
The abstract reports qualitative categories without pooled numerical effect sizes. There was strong evidence of breast milk responsiveness to maternal intake for DHA, EPA, vitamins A, E, and K, iodine, and selenium. Some evidence of responsiveness was observed for alpha-linolenic acid, B vitamins, vitamins C and D, ovalbumin, tyrosine, and contaminants. Evidence was insufficient to determine effects on arachidonic acid, copper, iron, zinc, and choline.
Why it matters
This review distinguishes which breast milk nutrients reflect maternal intake versus those that are tightly regulated, supporting targeted supplementation such as DHA and vitamin B12 for lactating women on restrictive diets.
Limits
High heterogeneity across the 88 included studies prevented quantitative meta-analysis, and no numerical effect sizes or confidence intervals are reported in the abstract. Evidence was insufficient to draw conclusions for several key micronutrients, including iron, zinc, copper, and choline.
Cited by
- contradicts Human breast milk contains vitamin D and all eight B vitamins derived from the mother's microbiome.