Breast milk immune factors in Bangladeshi women supplemented postpartum with retinol or beta-carotene.
BACKGROUND
Vitamin A supplementation of mothers postpartum may improve infant health, not only by increasing vitamin A delivery to the infant through breast milk but also by increasing delivery of milk immune factors. Our hypothesis was that postpartum supplementation with vitamin A increases milk concentrations of certain soluble immune factors.


METHODS
In a double-blind trial conducted in Matlab, Bangladesh, women at 1-3 wk postpartum were randomly assigned to receive until 9 mo postpartum 1) a single dose of 60 mg retinol as retinyl palmitate followed by daily placebos (n = 69), 2) daily doses of 7.6 mg beta-carotene (n = 72), or 3) daily placebos (n = 71). Milk samples collected at baseline and 3 mo postpartum were analyzed by enzyme-linked immunosorbent assay for secretory immunoglobulin A, lactoferrin, lysozyme, and interleukin 8; by HPLC for total retinol; and by atomic absorption spectroscopy for sodium and potassium.


RESULTS
After mammary epithelial permeability (defined as an elevated Na:K) and baseline immune factor concentrations were controlled for, there were no significant treatment effects on immune factors at 3 mo. Increased mammary permeability was common (25% of women at baseline and 12% at 3 mo) and was associated with higher concentrations of milk immune factors. Low body vitamin A stores at baseline, as assessed by the modified-relative-dose-response test, were associated with a higher Na:K, but neither retinol nor beta-carotene supplementation affected the prevalence of increased mammary permeability.


CONCLUSIONS
Postpartum vitamin A supplementation does not increase milk concentrations of immune factors. The causes of increased mammary epithelial permeability in this population require further study.
Filteau
S M
SM
Centre for International Child Health, Institute of Child Health, London, United Kingdom. sfilteau@ich.ucl.ac.uk
Rice
A L
AL
Ball
J J
JJ
Chakraborty
J
J
Stoltzfus
R
R
de Francisco
A
A
Willumsen
J F
JF
D001459:Bangladesh; D002214:Capsules; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007071:Immunoglobulin A, Secretory / Q000032:analysis; D016209:Interleukin-8 / Q000032:analysis; D007781:Lactoferrin / Q000032:analysis; D008895:Milk, Human / Q000276:immunology*; D009113:Muramidase / Q000032:analysis; D049590:Postpartum Period; D013997:Time Factors; D014801:Vitamin A / Q000008:administration & dosage*; D019207:beta Carotene / Q000008:administration & dosage*
D002214:Capsules; D007071:Immunoglobulin A, Secretory; D016209:Interleukin-8; D019207:beta Carotene; D014801:Vitamin A; D009113:Muramidase; D007781:Lactoferrin