Vitamin Concentrations in Human Milk Vary with Time within Feed, Circadian Rhythm, and Single-Dose Supplementation

Abstract

Background: Human milk is the subject of many studies, but procedures for representative sample collection have not been established. Our improved methods for milk micronutrient analysis now enable systematic study of factors that affect its concentrations.Objective: We evaluated the effects of sample collection protocols, variations in circadian rhythms, subject variability, and acute maternal micronutrient supplementation on milk vitamin concentrations.Methods: In the BMQ (Breast-Milk-Quality) study, we recruited 18 healthy women (aged 18–26 y) in Dhaka, Bangladesh, at 2–4 mo of lactation for a 3-d supplementation study. On day 1, no supplements were given; on days 2 and 3, participants consumed ∼1 time and 2 times, respectively, the US-Canadian Recommended Dietary Allowances for vitamins at breakfast (0800–0859). Milk was collected during every feeding from the same breast over 24 h. Milk expressed in the first 2 min (aliquot I) was collected separately from the remainder (aliquot II); a third aliquot (aliquot III) was saved by combining aliquots I and II. Thiamin, riboflavin, niacin, and vitamins B-6, B-12, A, and E and fat were measured in each sample.Results: Significant but small differences (14–18%) between aliquots were found for all vitamins except for vitamins B-6 and B-12. Circadian variance was significant except for fat-adjusted vitamins A and E, with a higher contribution to total variance with supplementation. Between-subject variability accounted for most of the total variance. Afternoon and evening samples best reflected daily vitamin concentrations for all study days. Acute supplementation effects were found for thiamin, riboflavin, and vitamins B-6 and A at 2–4 h postdosing, with 0.1–6.17% passing into milk. Supplementation was reflected in fasting, 24-h postdose samples for riboflavin and vitamin B-6. Maximum amounts of dose-responding vitamins in 1 feeding ranged from 4.7% to 21.8% (day 2) and 8.2% to 35.0% (day 3) of Adequate Intake.Conclusions: In the milk of Bangladeshi mothers, differences in vitamin concentrations between aliquots within feedings and by circadian variance were significant but small. Afternoon and evening collection provided the most-representative samples. Supplementation acutely affects some breast-milk micronutrient concentrations. This trial was registered at clinicaltrials.gov as NCT02756026.

Correlations between Maternal, Breast Milk, and Infant Vitamin B12 Concentrations among Mother–Infant Dyads in Vancouver, Canada and Prey Veng, Cambodia: An Exploratory Analysis

“…In addition, a full breast expression was collected, and samples were collected from the majority of women first thing in the morning, which helps to limit intra-participant diurnal variation, although this is not a major concern with vitamin B12 [22]. We also employed current laboratory methods to assess milk vitamin B12 [15]; older methods may have incorrectly measured vitamin B12 analogues.…”

Establishing a case definition of thiamine responsive disorders among infants and young children in Lao PDR: protocol for a prospective cohort study

“…The concentration of ThDP will be measured using the well-established thiochrome reaction coupled with high-performance liquid-chromatography fluorescence detection method 28 29. The assay of ETK will be completed by UV spectrophotometer at the NIHR BRC Nutritional Biomarker Laboratory at the University of Cambridge in the UK.…”

“…Breast milk of the fuller breast will be collected into a breast-milk bag with an electronic hospital-grade breast pump (Symphony Pump, Medela AG, Baar, Switzerland) until the breast is emptied. Since circadian differences in concentrations of thiamine and other vitamins are small,28 the breast-milk sample will be collected at any time of day. Time of day, time since last meal, breast side, time since last emptying of that side and milk volume will be recorded.…”

Lipidome analysis of milk composition in humans, monkeys, bovids, and pigs.

“…Besides nutritional components, milk contains steroid and peptide hormones, including leptin, ghrelin, and adiponectin [9], immune and growth factors [2,10,11], as well as poly-unsaturated fatty acids directly participating in the infant tissue development and growth [12,13]. The most variable element of milk composition is total fat content ranging from 60% in the hooded seals [14] to less than 1% in white rhinoceroses and ring-tailed lemur [15] -the phenomenon mainly linked to the duration of breastfeeding and ecological conditions.…”

“…The most variable element of milk composition is total fat content ranging from 60% in the hooded seals [14] to less than 1% in white rhinoceroses and ring-tailed lemur [15] -the phenomenon mainly linked to the duration of breastfeeding and ecological conditions. In most species, however, a single lipid class, triacylglycerides (TAGs), composes on average, 98% of the milk fat [11]. TAGs have simple chemical composition, consisting of glycerol and three fatty acid residues.…”