Diurnal variations in folacin levels of human milk: use of a single sample to represent folacin concentration in milk during a 24-h period

• Published in: The American journal of clinical nutrition Vol. 45; no. 4; pp. 770 - 779
• Main Authors: Udipi, S A, Kirksey, A, Roepke, J L
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Elsevier Inc 01.04.1987; American Society for Clinical Nutrition
• Subjects: ACIDE FOLIQUE; ACIDO FOLICO; Adult; ALIMENTOS; Biological and medical sciences; Circadian Rhythm; COMPOSICION; COMPOSITION; Female; Folic Acid - administration & dosage; Folic Acid - metabolism; Fundamental and applied biological sciences. Psychology; Humans; INFANTES; Lactation - metabolism; LAIT HUMAIN; LECHE HUMANA; Milk, Human - metabolism; Mother. Fetoplacental unit. Mammary gland. Milk; NOUVEAU-NE; NUTRICION; NUTRITION; Pregnancy; Pregnancy. Parturition. Lactation; PRODUIT ALIMENTAIRE; RITMOS BIOLOGICOS; RYTHME BIOLOGIQUE; Time Factors; Vertebrates: reproduction; Human; Human milk; Chemical composition; B-Vitamins; Circadian rhythm; Folic acid
• ISSN: 0002-9165; 1938-3207
• DOI: 10.1093/ajcn/45.4.770

Studies of breast-feeding and its adequacy for the infant could be simplified if a single milk sample were representative of nutrient levels during a 24-h period, despite diurnal variation. In this study, free and total folacin levels were measured in samples collected from 27 well-nourished mothers at each infant feeding from 2 wk to 1 yr of lactation. Folacin levels were higher (p less than 0.05) in the afternoon and evening than in the morning; variations decreased as lactation progressed (greater than 8 mo) and paralleled the decreased number of daily feedings. Despite 2- to 3-fold variations in milk folacin levels occur a 24-h period during the first 10 mo of lactation, the level in a single sample obtained at 1300-1450 h was representative (r = 0.74-0.93) of mean folacin concentration in samples obtained from all feedings during a 24-h period.