Sources and Fates of Docosahexaenoic Acid (DHA): A Review Study

Abstract

Docosahexaenoic acid (DHA) is an essential omega-3 polyunsaturated fatty acid with profound importance for human health. It is a critical structural component of neuronal and retinal membranes, underpinning its vital role in cognitive function and visual acuity. While endogenous synthesis from alpha-linolenic acid is possible, the conversion rate in humans is notoriously low, making pre-formed DHA from the diet indispensable. This mini-review consolidates current knowledge on the sources and fates of DHA. We first detail its primary origins, ranging from marine fish and seafood to algal oils, which serve as a sustainable, vegetarian alternative. The review then delineates the metabolic journeys of DHA upon ingestion: its incorporation into phospholipid membranes of target tissues, its role as a precursor for potent specialized pro-resolving mediators that quell inflammation, and its catabolism for energy. By synthesizing the pathways from intake to utilization, this review highlights the critical importance of adequate DHA intake for maintaining physiological functions across the lifespan and informs nutritional strategies to prevent deficiency.