Cobalamins in human pregnancy and lactation

Area of Science:

• Biochemistry
• Human Nutrition
• Analytical Chemistry

Background:

• Cobalamins (Vitamin B12) are essential micronutrients crucial for various physiological processes.
• Understanding cobalamin status in maternal and infant populations is vital for ensuring adequate nutrition.
• Variations in cobalamin forms and concentrations may impact health outcomes.

Purpose of the Study:

• To analyze and compare cobalamin forms in maternal plasma, fetal blood, human milk, and cow's milk.
• To investigate quantitative and qualitative differences in plasma cobalamins during pregnancy and postpartum.
• To assess cobalamin distribution between maternal plasma and breast milk.

Main Methods:

• Chromatography and bioautography were employed for the quantitative analysis of cobalamins.
• Samples analyzed included maternal blood, fetal blood, human milk, cow's milk, and dried cow's milk.
• Comparative analysis was performed between different physiological states and milk types.

Main Results:

• Plasma cobalamin levels and proportions differed significantly in pregnant and postpartum women compared to non-pregnant individuals.
• Distinct cobalamin profiles were observed between mothers and their newborn infants.
• Breast milk showed a higher proportion of 5-deoxyadenosyl cobalamin relative to methylcobalamin compared to maternal plasma.
• Parenterally administered cyanocobalamin was detected in maternal plasma and breast milk.
• Fresh cow's milk was rich in 5-deoxyadenosyl cobalamin, while dried milk contained hydroxocobalamin and cyanocobalamin.

Conclusions:

• Methylcobalamin may be a more labile form of cobalamin in plasma than 5-deoxyadenosyl cobalamin.
• The findings highlight significant variations in cobalamin forms and concentrations across different biological matrices and physiological conditions.
• The study provides insights into cobalamin transport mechanisms and has implications for maternal and infant nutrition.