[Science Update] Maternal iodine deficiency and human milk composition

2 min read /
General Nutrition Obstetrics / Gynaecology Public health

In this study, the influence of maternal iodine deficiency on the metabolome and elemental composition of human milk was examined through a metabolomic analytical approach. Lactating women with normal and deficient iodine status were clearly distinguished accordingly to their multi-element and metabolomic profiles.

Samples collection:

  • 40 transitional human milk samples were collected by manual expression or by pump within 48 hours after delivery
  • Urine samples were taken from pregnant women when they were admitted for giving birth to measure urine iodine concentration

Analytical method:

  • An integrated analytical multiplatform has been applied. It was based on:
    • Gas chromatography coupled to mass spectrometry
    • Ultra-high performance liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry

Key findings:

  • Levels of selenium, zinc and copper were significantly lower in human milk of women with iodine deficiency* as compared with that of normal women
  • 31 metabolites were remarkably altered in the human milk of women with iodine deficiency* compared with women with normal iodine status,
    • They belong to various metabolic pathways influencing mother-offspring transport of crucial molecules, e.g.
      • Lower levels of glycerophospholipids involved in neurodevelopment
      • Generally lower levels of metabolites of the tricarboxylic acid (TCA) cycle
      • Higher levels of 1,25-dihydroxyvitamin D3-lactone that is a seco-cholestane (a hydroxy seco-steroid, a member of the group of D3 vitamins, a secondary alcohol and a steroid hormone)

Iodine deficiency was defined according to the World Health Organization (WHO) criteria for pregnant women who show urine iodine levels below 150 mcg per liter

Link to the full article:



Arias-Borrego A et al. Iodine deficiency disturbs the metabolic profile and elemental composition of human breast milk. Food Chem. 2022;371:131329.

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