Ron's diet lacks niacin. he hasn't developed pellagra, because he consumes a high-protein diet that contains plenty of _____, the precursor for niacin.
Tryptophan is the precursor for niacin so it can be used to synthesize the niacin that Ron's diet lack of. But it will need about 60mg tryptophan to synthesize 1mg of niacin. Niacin is vitamin B3 complex that has role in lipid metabolism. Deficiency of niacin will cause a disease called pellagra.