Vitamin A Deficiency Changes Jejunal Mucosal Fatty Acid Profile in Rats

Changes in intestinal epithelial integrity have been postulated to explain the association between vitamin A status and diarrhoeal disease in children living in areas where vitamin A deficiency is a major public health problem. Fatty acids are an integral component of normal enterocyte structure, and changes to their profile in the intestinal mucosa may impact on the efficacy of the mucosal barrier. The aim of this study therefore was to determine the effect of vitamin A deficiency on intestinal mucosal fatty acid profile. Weanling male specific pathogen free rats were maintained on a vitamin A deficient diet for either 40-42 (subclinical deficiency) or 60-63 days (clinical deficiency), and compared with rats pair fed or allowed free access to the same diet, but supplemented with vitamin A (vitamin A sufficient). Fatty acid profile of jejunal mucosal homogenates was determined using gas chromatography. While subclinically vitamin A deficient rats had only minor differences in fatty acid profile as compared with pair fed and vitamin A sufficient rats, there were marked differences in a number of fatty acids in the clinically vitamin A deficient rats. Clinically vitamin A deficient rats had more arachidonic acid (C20: 4n-6) than pair fed rats, and less linoleic acid (C18: 2n-6) than both pair fed and vitamin A sufficient rats. These findings suggest that vitamin A deficiency modifies intestinal mucosal fatty acid composition such that there is an increase in proinflammatory eicosanoid precursors. This may contribute towards our understanding of a biological mechanism of the epidemiological association between vitamin A status and diarrhoeal disease.