As one who is A1298C -Ho I'm concerned about low BH4 and the related buildup of Ammonia, Peroxinitrite, Superoxide as a result. Came across something interesting today. Apparently, Watermelon (especially the rind) is high in all the cofactors that drive the urea cycle -- Ornithine, Citrulline and Arginine. A study indicated that watermelon increased arginine and ornithine 22% and 18% respectively and citrulline is derived but not elevated but that's because it's converted into arginine. http://www.ncbi.nlm.nih.gov/pubmed/17352962 As an added bonus, these components in watermelon increase HGH. http://www.nutritionalhealthenterprises.com/newsletter_detail.ews?newsletter.ewdid=19 Any other thoughts on lowering Ammonia, Peroxinitirite, Superoxide and also Phenylalanine (though not part of this cycle) would be appreciated.