<prompt> Which of the following is elevated in Pyridoxal Phosphate deficiency?FIGLUHomocystineMethylmalonic acidXanthurenic acid  <response>: Xanthurenic acid Homocysteine Both are increased in PLP deficiency 3-OH Kynurenine is one of the intermediate in Tryptophan catabolism Normally conveed to next intermediate and this conversion requires vitamin B6 PLP. But in B6 deficiency, 3-OH Kynurenine is diveed to form alternate metabolite Xanthurenic acid See fig which is excreted in urine. Homocystine is a chemical compound consisting of two homocysteine molecules joined by a disulfide. 