Fatty Acids and Fat-Soluble Vitamins in Breast Milk: Physiological Significance and Factors Affecting Their Concentrations.

Fatty acids (FAs) and fat-soluble vitamins are vital components of the human milk lipid fraction. About two-thirds of the human milk FA fraction consist of oleic, linoleic, and palmitic FAs, but the precise composition depends on maternal geography, diet, and genetics. Mothers with high fish consumption have more docosahexaenoic acid (DHA) and other ω-3 FAs in their milk, while mothers with high dairy consumption have more branched-chain FAs in their milk. Vitamins A and E are the most common fat-soluble vitamins, but milk concentrations vary, depending on maternal diet and body stores. Vitamin D is typically low or undetectable in mother's milk and typically fails to meet the infant needs. However, trial data indicate that high maternal supplementation (6,400 IU/day) safely provides nutritionally adequate amounts of vitamin D in her milk. FA and fat-soluble vitamin levels in mother's milk can significantly influence infant health; for example, in preterm infants, low endogenous stores of DHA paired with low levels in maternal milk may influence the risk of chronic lung disease and other inflammatory conditions. Greater attention is warranted to the variation in FA and fat-soluble vitamin content of human milk in relation to infant health.