(P22-21-26) Maternal Supplementation Effects on Human Milk Micronutrients: Exploratory Applications of Reference Values from the Mothers, Infants and Lactation Quality (MILQ) Study

Objectives: Valid nutrient reference values (RVs) for assessing micronutrients (MN) in human milk have been limited. Using proposed RVs from the Mothers, Infants and Lactation Quality (MILQ) Study, we evaluated the effects of MN supplementation on milk vitamins (A, E, B1–7, B12) and minerals (Fe, Se, Ca, Cu, Zn) .

Methods: Individual-participant milk MN concentrations from 6 randomized controlled trials (RCTs) that provided ~1–2 times the Recommended Dietary Allowance of multiple MNs were converted to continuous percentiles (pct) based on postpartum age-specific MILQ RVs. RCTs provided: Small-quantity Lipid-based Nutrient Supplements (iLiNS—Ghana [N=754], Malawi [N=315]; BAN—Malawi [N=537]); Balanced Energy-Protein (MISAME—Burkina Faso [N=290]; Mumta LW–Pakistan [N=150]); and Oral Tablets (JiVitA-3—Bangladesh [N=752]; iLiNS—Ghana, Malawi). Each MN pct outcome was analyzed separately for each study using non-parametric contrasts between intervention and control groups. Analyses were stratified by supplementation period: pregnancy only, lactation only, and pregnancy plus lactation.

Results: Supplementation during pregnancy and/or lactation generally resulted in higher B-vitamin pcts relative to controls. Significant (p < 0.05) comparisons favoring intervention were observed for B1:11 of 20 contrasts examined; B2: 8 of 12; B3: 6 of 12; B5: 10 of 13; B6: 7 of 12; B7: 2 of 11; B12: 4 of 20. Yet, for B3, > 50% of supplemented individuals in most RCTs had milk concentrations ≤ the 50th pct. Significant effects on fat-soluble vitamins were limited (retinol: 2 of 16 contrasts; α-tocopherol:1 of 12). Pregnancy-only supplementation showed minimal influence on milk MN pcts at 1–4 months postpartum, except for Selenium (Se). Among 5 RCTs administering mineral-containing supplements, Se was the only mineral with significant increases in 2 contrasts, though individual concentrations remained < the 25th pct. In scenarios where interventions had significant effects, median vitamin pcts often remained ≤ the 50th.

Conclusions: We provide the first application of recently published human milk nutrient RVs to assess the impact of maternal supplementation on milk MN concentrations. While supplementation can increase some milk MN concentrations, population status and intervention timing influence the magnitude of response.

Funding Sources: Gates Foundation, USDA ARS