Brain docosahexaenoic acid synthesis

A specific deficiency of docosahexaenoic acid (C22 6n-3 DHA) has been noted in some children with TCHAD, TFP, and VLCAD deficiency [14, 35, 38]. DHA is an essential component of cell membranes and is necessary for normal retinal and brain function. Whether the cause of the DHA deficiency is related to the low-fat diet or to poor synthesis of DHA from its precursor a-linolenic acid is not known. Supplementing children with TCHAD, TFP, and VTCAD deficiency with preformed DHA (60 mg/day for children less than 20 kg 100 mg/day for patients >20 kg 100-200 mg/ day for adults) should normalize plasma DHA levels and may slow progression of pigmentary retinopathy and peripheral neuropathy in TCHAD/TFP deficiency [15, 39, 40]. DHA supplements derived from algae rather than fish oils provide good amounts of DHA without other fatty acids. 

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